Patent Publication Number: US-2020287071-A1

Title: Time of Flight Sensor Device and Time of Flight Sensor Arrangement

Description:
TECHNICAL FIELD 
     Embodiments relate in general to the field of integrated circuits and, more specifically, to the field of optical sensor devices adapted to detect a time of flight of an electromagnetic signal. Thus, embodiments relate to a time of flight (TOF) sensor device. Further embodiments are directed to N-epi time of flight sensor device having a n-doped semiconductor region in a semiconductor substrate, e.g. bulk or epitaxial grown semiconductor substrate. 
     BACKGROUND 
     Current optical time of flight sensors employ photogate structures for redirecting photo-generated charge carriers in a semiconductor substrate to a read-out node for achieving time of flight information of an amplitude-modulated electromagnetic signal generated by a radiation source, wherein the electromagnetic signal is directed to an object and reflected to the time of flight sensor device. 
     However, the current design of optical time of flight sensor devices suffers from limitations of the quality of the sensor signal, i.e., on the efficiency of the transport of the photo-generated charge carries to the readout node(s), for achieving a good signal-to-noise ratio and a high temperature operability. 
     Therefore, there is a need for improved optical time-of-flight sensor devices with an enhanced capability to convert the received optical signal into an electrical signal. 
     Such a need can be solved by the time of flight sensor device according to the independent claims. In addition, specific implementations of different embodiments of the time of flight sensor device are defined in the dependent claims. 
     SUMMARY 
     According to an embodiment, a time of flight sensor device comprises: a semiconductor substrate comprising a conversion region to convert an electromagnetic signal into photo-generated charge carriers and comprising a substrate doping region having a n doping type, wherein the substrate doping region extends from a first main surface region of the semiconductor substrate into the semiconductor substrate, wherein the semiconductor substrate has adjacent to the substrate doping region a p doped region, and wherein the substrate doping region at least partially forms the conversion region in the semiconductor substrate, a readout node arranged in the semiconductor substrate within the substrate doping region and having the n-doping type, wherein the readout node is configured to readout the photo generated charge carriers; and a control electrode arranged in the substrate doping region and having the p-doping type. 
     According to another embodiment, a time of flight sensor device comprises: a semiconductor substrate comprising a conversion region to convert an electromagnetic signal into photo-generated charge carriers, and comprising a substrate doping region having a n doping type, wherein the substrate doping region extends from a first main surface region of the semiconductor substrate into the semiconductor substrate, wherein the semiconductor substrate has adjacent to the substrate doping region a p-doped region, and wherein the substrate doping region at least partially forms the conversion region in the semiconductor substrate, a readout node arranged in the semiconductor substrate within the substrate doping region and having the n doping type, wherein the readout node is configured to readout the photo generated charge carriers, a control electrode arranged in or on the substrate doping region of the semiconductor substrate, and a buried doping layer in the semiconductor substrate having a higher concentration of the p doping type than p-doped region of the semiconductor substrate adjacent to the substrate doping region, wherein the buried doping layer is formed in the semiconductor substrate and vertically below the substrate doping region in the semiconductor substrate. 
     According to another embodiment, a time of flight sensor device comprises: a semiconductor substrate comprising a conversion region to convert an electromagnetic signal into photo-generated charge carriers, and comprising a substrate doping region having a n doping type, wherein the substrate doping region extends from a first main surface region of the semiconductor substrate into the semiconductor substrate, wherein the semiconductor substrate has adjacent to the substrate doping region a p-doped region, and wherein the substrate doping region at least partially forms the conversion region in the semiconductor substrate, a readout node arranged in the semiconductor substrate within the substrate doping region and having the n doping type, wherein the readout node is configured to readout the photo generated charge carriers; a control electrode arranged in or on the substrate doping region of the semiconductor substrate, and a trench structure which is arranged laterally with respect to the substrate doping region and which extends vertically with respect to the first main surface region of the semiconductor substrate in the semiconductor substrate. 
     According to another embodiment, a time of flight sensor arrangement comprises: a plurality of the time of flight sensor devices, wherein the time of flight sensor devices are arranged in an array, and a controller for providing a control signal to the control electrode. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Embodiments of the time of flight sensor device are described herein making reference to the appended drawings and figures. 
         FIG. 1A  shows a schematic cross sectional view of a time of flight sensor device according to an embodiment. 
         FIGS. 1B-1C  show schematic cross sectional views of the time of flight sensor device according to further embodiments. 
         FIGS. 1D-1E  show schematic cross sectional views along a vertical axis of the time of flight sensor device according to further embodiments. 
         FIG. 2A  shows a schematic cross sectional view of the time of flight sensor device according to a further embodiment. 
         FIG. 2B  shows a schematic plot of the doping concentration of the buried doping layer as shown in  FIG. 2A  in the depth direction (z-direction) of the semiconductor substrate. 
         FIGS. 3A-3H  show schematic cross sectional views of the time of flight sensor device according to further embodiments. 
         FIG. 3I  shows schematic cross sectional views of the time of flight sensor device according to further embodiments. 
         FIG. 4  shows a schematic cross sectional view of the time of flight sensor device according to a further embodiment. 
         FIGS. 5A-5B  show schematic cross sectional views of the time of flight sensor device according to further embodiments. 
         FIG. 6  shows a schematic cross sectional views of the time of flight sensor device according to further embodiments. 
         FIG. 7  shows an exemplary schematic circuit diagram of a time of flight sensor arrangement according to a further embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Before discussing the present embodiments in further detail using the drawings, it is pointed out that in the figures and the specification identical elements and elements having the same functionality and/or the same technical or physical effect are usually provided with the same reference numbers or are identified with the same name, so that the description of these elements and of the functionality thereof as illustrated in the different embodiments are mutually exchangeable or may be applied to one another in the different embodiments. 
     In the following description, embodiments are discussed in detail, however, it should be appreciated that the embodiments provide many applicable concepts that can be embodied in a wide variety of semiconductor devices. The specific embodiments discussed are merely illustrative of specific ways to make and use the present concept, and do not limit the scope of the embodiments. In the following description of embodiments, the same or similar elements having the same function have associated therewith the same reference signs or the same name, and a description of the such elements will not be repeated for every embodiment. Moreover, features of the different embodiments described hereinafter may be combined with each other, unless specifically noted otherwise. 
     It is understood that when an element is referred to as being “connected” or “coupled” to another element, it may be directly connected or coupled to the other element, or intermediate elements may be present. Conversely, when an element is referred to as being “directly” connected to another element, “connected” or “coupled,” there are no intermediate elements. Other terms used to describe the relationship between elements should be construed in a similar fashion (e.g., “between” versus “directly between”, “adjacent” versus “directly adjacent”, and “on” versus “directly on”, etc.). 
     For facilitating the description of the different embodiments, the figures comprise a Cartesian coordinate system x, y, z, wherein the x-y-plane corresponds, i.e. is parallel, to the first main surface region of the semiconductor substrate, and wherein the depth direction vertical to the first main surface region and into the semiconductor substrate corresponds to the “z” direction, i.e. is parallel to the z direction. In the following description, the term “lateral” means a direction parallel to the x-direction, wherein the term “vertical” means a direction parallel to the z-direction. 
       FIG. 1A  shows a schematic cross sectional view of a time of flight sensor device  100  according to an embodiment. 
     As shown in  FIG. 1A , the time of flight (TOF) sensor device  100  comprises a semiconductor substrate  110 . The semiconductor substrate  110  for instance presents a generally rectangular cross-section along a vertical axis (i.e. in the depth direction or z direction). The semiconductor substrate  110  comprises a conversion region  112  to convert an electromagnetic signal “S 1 ” into photo-generated charge carriers  114   a ,  114   b , wherein the semiconductor substrate  100  further comprises a substrate doping region  116  having a n-doping type. The substrate doping region  116  extends from a first main surface region  110 -A of the semiconductor substrate  110 , which may form a top surface thereof, into the semiconductor substrate  110  (in the depth direction or z direction). The semiconductor substrate  110  may comprise silicon, germanium or any other semiconductor material. The semiconductor substrate  110  may comprise a bulk or epitaxially grown semiconductor material. 
     The remaining region  110 - 1  of the semiconductor substrate  110 - 1  adjacent to the substrate doping region  116  has a p-doping type. The substrate doping region  116  at least partially forms the conversion region  112  in the semiconductor substrate  110 . A readout node  120  is arranged in the semiconductor substrate  110  within the substrate doping region  116  and has the n-doping type, e.g. with a higher doping concentration than the substrate doping region  116 . The readout node  120  is configured to readout the photo-generated charge carries  114   b , e.g., the photo-generated electrons. The photo-generated charge carries  114   b  (electrons) have the same type as the minority carriers in the substrate region  110 - 1 . The readout node  120  may be formed as an implanted doping region in the semiconductor substrate  110 . 
     The conversion region  112  is also referred to as absorption region in the semiconductor substrate  110  for receiving the electromagnetic signal S 1 , which is incident to first main surface region  110 -A of the semiconductor substrate  110 , and for generating electron-hole pairs (e/h-pairs). Thus, the portion of the incident electromagnetic signal S 1 , which enters the conversion region  112 , is at least partially converted into the photo-generated charge carriers  114   a ,  114   b  (e/h-pairs), wherein, for example, the negative charge carriers  114   b  (electrons) are shifted to the readout node  120 . 
     The TOF sensor device  100  further comprises a control electrode  122  which is arranged in the substrate doping region  116  of the semiconductor substrate  110  adjacent to the first main surface region  110 -A of the semiconductor substrate  110 . The control electrode  122  has the p-doping type. As shown in  FIG. 1A , the control electrode  122  may optionally be further arranged in the conversion region  112  adjacent to the first main surface region  110 -A of the semiconductor substrate  110 . The control electrode  122  may be formed as implanted doping region in the semiconductor substrate  110 . 
     The TOF sensor device  100  may further comprise a substrate contact  126  which may be arranged at the p-doping type region  110 - 1  of the semiconductor substrate  110  adjacent to the substrate doping region  116 . The substrate contact  126  may be arranged, for example, to receive and discharge the positive charge carriers  114   a , e.g. holes, photo-generated in the conversion region  112 . This may avoid a saturation of the semiconductor substrate  110  by positive charge carriers  114   a  (holes). 
     The substrate doping region  116  may comprise a n-type doping concentration (of doping atoms) in the range between 1E12 atoms/cm 3  and 1E16 atoms/cm 3 , or between 1E13 atoms/cm 3  and 1E15 atoms/cm 3 , for example. The substrate doping region  116  may extend between 1 μm and 100 μm, between 2 μm and 50 μm, or between 3 μm and 20 μm into the semiconductor substrate  110 , for example. 
     It should be noted that the formulation 1EX atoms/cm 3  is intended to be equivalent to the formulation 10 X  atoms/cm 3 . 
     The aspect ratio of the doping region  116 , that is the maximum vertical extension of the doping region  116  relative to a lateral extension of the doping region  116  may be between 0.2 and 5, in some embodiments between 0.5 and 2 and in some embodiments between 0.75 and 1.25. 
     According to an embodiment, the minimum doping concentration of the conversion region  112  is inside the n-doped substrate doping region  116 . The minimum mean or average doping concentration may refer to a minimum number of doping atoms (independent from their charge, therefore positive and negative) per cubic-centimeter. 
     The p-doped region  110 - 1  of the semiconductor substrate  110  may comprise a p-type doping concentration (=substrate doping concentration) in the range between 1E12 atoms/cm 3  and 1E19 atoms/cm 3 , or between 1E14 atoms/cm 3  and 1E18 atoms/cm 3 , or between 1E15 atoms/cm 3  and 1E17 atoms/cm 3  for example. 
     The readout node  120  may comprise a n-type doping concentration greater than 1E14 atoms/cm 3  or in the range between 1E14 atoms/cm 3  and 1E22 atoms/cm 3 , or between 1E16 atoms/cm 3  and 1E21 atoms/cm 3 , or between 1E18 atoms/cm 3  and 5E20 atoms/cm 3 , for example. 
     The control electrode  122  may comprise a p-type doping concentration greater than 1E14 atoms/cm 3  or in the range between 1E14 atoms/cm −3  and 1E22 atoms/cm −3 , or between 1E16 atoms/cm 3  and 1E21 atoms/cm 3 , or between 1E18 atoms/cm 3  and 5E20 atoms/cm 3  for example. The implanted control electrode  122  may extend up to a depth of 10 μm, 2 μm or 0.5 μm into the semiconductor substrate  110 . 
     As shown in  FIG. 1A , the substrate doping region  116  may laterally (in the ±x direction) extend beyond the conversion region  112  in the semiconductor substrate. In this case, only a part of the substrate doping region  116  contributes to the conversion region  112  in the semiconductor substrate  110 . 
     Furthermore, the conversion region  112  may vertically (in the z-direction or depth direction) extend beyond the substrate doping region  116  in the semiconductor substrate  110 , e.g., to the second main surface region  110 -B of the semiconductor substrate  110 . A bottom portion of the conversion region  112  is then formed by a portion of the region  110 - 1 . 
     According to a further embodiment, the entire substrate doping region  116  of the semiconductor substrate  110  may be part of the conversion region  112 . 
     The control electrode  122  in the substrate doping region  116  and adjacent to the first main surface region  110 -A of the semiconductor substrate  110  may be configured to provide, based on a control signal, an electrical potential distribution in the conversion region  112  and, thus, in the substrate doping region  116  for providing a phase sensitive or runtime-sensitive demodulation of the photo-generated charge carriers  114   b  in the conversion region  112 . Thus, the demodulation of the photo-generated charge carriers  114   b  may be achieved by means of a drift-based transport of the photo-generated charge carriers  114   b  to the respective readout node  120 . A controller (not shown in  FIG. 1A ) may apply the control signal to the control electrode  122 . Thus, the control electrode  122  is used to demodulate the photo-generated charge carriers  114   b.    
     To summarize, one type of the photo-generated charge carriers, namely, the electrons  114   b  are demodulated by means of the control electrode(s)  122 , wherein the other type of photo-generated charge carrier, namely the holes  114   a , is not demodulated but rather flows into the common substrate contact  126 . 
     According to an embodiment, a radiation source (not shown in  FIG. 1A ) generates an electromagnetic signal S 0 , which is amplitude-modulated by a modulation signal. The electromagnetic signal S 0  is directed to an object (not shown in  FIG. 1A ) and reflected to the time of flight sensor device  100 . Thus, the reflected portion S 1  of electromagnetic signal S 0  enters the conversion region  112  in the semiconductor substrate  110  and generates the photo-generated charge carriers  114   a ,  114   b . During operation of the time of flight sensor device  100 , a demodulation signal (=the control signal), which is in-phase with a modulation signal or has a fixed phase relationship to the modulation signal, is applied to the control electrode  122 . The photo-generated charge carriers  114   b , i.e. the electrons  114   b , are directed to the readout node  120  depending on the demodulation signal applied to the control electrode  122  and based on the resulting electrical potential distribution in the substrate doping region  116 . The photo-generated charge carriers  114   b  directed to the readout node  120  are detected and a phase shift between the modulation signal and the electromagnetic signal reflected from the object and detected at the TOF sensor device may be determined, e.g. by a processing device or controller (not shown in  FIG. 1A ). Therefore, the time of flight of the electromagnetic signal S 0  and of the reflected portion S 1  of the electromagnetic signal S 0  may be determined from the detected photo-generated carriers  114   b , which are provided at the readout node  120 . In other words, a mixing of the received electromagnetic radiation S 1  with the demodulation signal applied to the control electrode  122  is used to determine a time of flight information from the phase shift between the radiation emitted by the radiation source and the radiation received by the optical TOF sensor device  100 . 
     The substrate doping region  116  provides for an efficient demodulation even in vertical deep lying regions of the conversion region  112  and therefore the demodulation of the photo-generated charge carriers  114   b  is provided deep in the semiconductor substrate  110 . This in-volume demodulation avoids long path lengths and slow diffusive transport. A high electric field strength obtained provides for a fast extraction of the generated charge carriers  114   b  to the respective readout node. 
     According to an embodiment, the TOF sensor device  100  may optionally comprise a further control electrode  122 - 1  to optionally provide a pair of control electrodes  122 ,  122 - 1  and a further readout node  120 - 1  to optionally provide a pair of readout nodes  120 ,  120 - 1 . 
     The optional further control electrode  122 - 1  is also arranged in the substrate doping region  116  of the semiconductor substrate  110  and has the p-doping type. As shown in  FIG. 1A , the further control electrode  122 - 1  may also be arranged in the conversion region  112  adjacent to the first main surface region  110 -A of the semiconductor substrate  110 . The further control electrode  122 - 1  may be formed as implanted doping region in the semiconductor substrate  110 . The further control electrode  122 - 1  may comprise the same p-type doping concentration as the control electrode  122 , for example. 
     In case, the further control electrode  122 - 1  is arranged in the time of flight sensor device  100 , the above description with respect to the functionality of the control electrode  122  is equally applicable to the further control electrode  122 - 1 . 
     The optional further readout node  120 - 1  is arranged in the semiconductor substrate  110  within the substrate doping region  116  and has the n-doping type, e.g. with a higher doping concentration than the substrate doping region  116 . The further readout node  120 - 1  is also configured to readout the photo-generated charge carries  114   b , e.g., the photo-generated electrons. The further readout node  120 - 1  may be formed as further implanted doping region in the semiconductor substrate  110 . The further readout node  120 - 1  may comprise the same n-type doping concentration as the readout node  120 . 
     In case, the further readout node  120 - 1  is arranged in the time of flight sensor device  100 , the above description with respect to the functionality of the readout node  120 - 1  is equally applicable to the further readout node  120 - 1 . 
     Thus, the readout nodes  120 ,  120 - 1 , and the control electrodes  122 ,  122 - 1  can be arranged pairwise in the substrate doping region  116  and optionally in the conversion region  112  as well, wherein the pair of readout nodes  120 ,  120 - 1  may be symmetrically arranged with respect to a symmetry line  110 -C (=on opposing sides of the center line  110 -C), which extends parallel to the z-direction, wherein the pair of control electrodes  122 ,  122 - 1  may be also arranged symmetrically with respect to the symmetric line  110 -C (=on opposing sides of the center line  110 -C). Thus, the pairwise arranged readout nodes  120 ,  120 - 1  may each have the same distance x 1  parallel to the x-direction from the center line (symmetry line)  110 -C, wherein further the pairwise arranged control electrodes  122 ,  122 - 1  may each have the same distance x 2  parallel to the x-direction from the center line  110 -C. 
     The above described demodulation concept may be further applied to the pairwise arranged control electrodes  122 ,  122 - 1  and pairwise arranged readout nodes  120 ,  120 - 1  in that the photo-generated charge carriers  114   b  are directed to the first readout node  120  and subsequently to the second readout node  120 - 1  depending on the demodulation signal applied to the respective control electrode  122 ,  122 - 1 . The photo-generated charge carriers  114   b  (e.g. the electrons) directed to the respective readout node  120 ,  120 - 1  are detected and a phase shift between the modulation signal and the electromagnetic signal S 1  reflected from the object and detected at the time of flight sensor device  100  is derivable. Thus, a mixing of the received radiation S 1  with a demodulation signal is used to determine time of flight information from the phase shift between the emitted radiation S 0  from the radiation source and the radiation S 1  received by the optical time of flight sensor device  100 . 
     As shown in  FIG. 1A , a further substrate contact  126 - 1  may be optionally provided at the p-doped region  110 - 1  of the semiconductor substrate  110 . In case, the further substrate contact  126 - 1  is arranged, the above description with respect to the functionality of the substrate contact  126 - 1  is equally applicable to the further substrate contact  126 - 1 . 
     According to the embodiment of  FIG. 1A , the control electrode  122  and the optional further control electrode  122 - 1  are formed as p-doping regions in the substrate doping region  116  having a n-doping type. Based on the control electrode  122 ,  122 - 1 , a control signal (demodulation signal) applied to the respective control electrode  122 ,  122 - 1  creates an electric field with relatively deep equipotential lines in the semiconductor substrate so that the demodulation of the photo-generated charge carriers can be extended relatively deep into the semiconductor substrate  110  and provides an efficient demodulation of the photo-generated charge carriers. This effect can be efficiently achieved as the at least one “implanted” control electrode  122 ,  122 - 1  can extend relatively deep into the semiconductor substrate  110 . 
     As the at least one p-doped control electrode  122 ,  122 - 1  of the optical time of flight sensor device  100 , as described with respect to  FIG. 1A , is arranged in the substrate doping region  116  of the semiconductor substrate  110 , e.g. as implanted doping region, an absorption loss of the incident electromagnetic signal S 1 , which enters the conversion region  112 , may be avoided or at least reduced when compared to a control electrode design in form of metallization or polysilicon regions with an intermediate insulator layer on the main surface region  110 -A of the semiconductor substrate  110 . 
     Moreover, as the at least one p-doped control electrode  122 ,  122 - 1  of the optical time of flight sensor device  100 , as described with respect to  FIG. 1A , is arranged in the substrate doping region  116  of the semiconductor substrate  110 , e.g. as implanted doping region, a reduced leakage (shot noise) may be achieved. The leakage (shot noise) may result from electron/hole pair generation at the interface, e.g. a silicon-silicon dioxide interface at the first main surface region  110 - a  of the semiconductor substrate  110 , and may be efficiently reduced by the design of the “implanted” control electrode(s)  122 ,  122 - 1 . Thus, the time of flight sensor device  100  may provide a high signal-to-noise ratio (SNR) due to the reduced dark current from e/h pair-generation, for example, at an oxide interface inherent. 
     According to an embodiment, the optical time of flight sensor device  100  forms part of a device known as a pixel, which may further comprise further components, e.g. processing circuitry. This pixel itself forms part of a two-dimensional integrated pixel array for receiving optical visible or infrared radiation emitted by a light source and reflected by an object to be sensed, wherein the respective pixels provide an electrical output signal for determining a distance to the object by measuring the time-of-flight (travelling time) of the optical visible or infrared radiation. It should be noted that the time of flight sensor device  100  can be used in an apparatus comprising a single pixel, or within such an of an array of pixels. 
     As further illustrated in  FIG. 1A , and whether in the corresponding embodiment or in any embodiment of the invention, optionally, the substrate doping region  116  extends to one or more side, i.e. lateral edge, of the sensor device  100  over at least part of the height of the sensor device  100 . For instance, it so extends only over part of the height of the substrate doping region. For instance, the p-doped region  110 - 1  comprises a portion located adjacent and beneath the substrate contact  126  and/or the further substrate contact  126 - 1 . Alternatively, the substrate doping region  116  extends to the main surface region  110 -A in the vicinity of the corresponding lateral edge of the sensor device  100 . 
     For instance, the side or sides of a given sensor device  100  to which the substrate doping region  116  extends is a function of a location of the considered sensor device  100  within the pixel array. 
     For a non-edge sensor device  100 , i.e. a sensor device  100  having no lateral edge forming an outer boundary of the array, the substrate doping region  116  may extend to all the lateral edges of the sensor device. 
     For an edge sensor device  100 , i.e. a sensor having one or more lateral edge forming an outer boundary of the array, the substrate doping region  116  may not extend to the corresponding lateral edge(s) of the sensor device  100 , and the corresponding lateral edge(s) is formed by the material of the p-doped region  110 - 1 . 
     Within the array, two neighboring sensor devices  100  may be in contact with each other laterally, in which case their respective substrate doping regions  116  may be in contact with each other in the region of the lateral edges of the sensor devices  100 . 
     Alternatively, neighboring sensor devices  100  within the array may not be in contact with each other. 
     In some embodiments, whether that of  FIG. 1A  or any other, on one or more side of the sensor device  100 , the region  110 - 1  is arranged so as to form of a wall stretching over the entire span of the side of the sensor device  100 . It may stretch vertically over the entire height of the sensor device, or only over part of it, in which case the substrate doping region  116  may extend to the side of the sensor device above the region  110 - 1 . 
       FIG. 1D  shows a schematic cross sectional view of the time of flight sensor device  100 , wherein the drawing plane is parallel to the y-z-plane (=perpendicular to the drawing plane of  FIG. 1A ). As shown in  FIG. 1D , the region  110 - 1  is arranged so as to form of a wall stretching over the entire span of the side of the sensor device  100 . 
     However, alternatively, the region  110 - 1  is arranged so to as form a plurality of vertical columns with gaps therebetween. The substrate doping region  116  then extends to the corresponding side of the sensor device  100  between the gaps formed between the columns, as schematically shown in  FIG. 1E . 
     On the sides of the sensor device  100 , the matter of the region  110 - 1  may be formed e.g. by epitaxial growth or by implantation, whether in a same process step as the remainder of the region  110 - 1 , or in a prior or subsequent step. 
     In the following, a number of different possible implementations of the time of flight sensor device  100  are exemplarily described. 
     In the present description of embodiments, the same or similar elements having the same structure and/or function are provided with the same reference numbers or the same name, wherein a detailed description of such elements will not be repeated for every embodiment. Thus, the above description with respect to  FIG. 1A  is equally applicable to the further embodiments as described below. In the following description, essentially the differences, e.g. additional elements, to the embodiment as shown in  FIG. 1A  and the technical effect(s) resulting therefrom are discussed in detail. 
       FIG. 1B  shows a schematic cross sectional view of an optical time of flight sensor device according to a further embodiment. 
     As shown in  FIG. 1B , a sensor electrode  130 , e.g. a so-called separation gate or photogate (modulation gate), which is optionally separated by an isolating material  132  form the semiconductor substrate  110  may be arranged on the first main surface region  110 -A of the semiconductor substrate  110 . As shown in  FIG. 1B , the sensor electrode  130  may be arranged in a lateral direction between the control electrode  122  and the readout node  120 . The sensor electrode  130  may be configured to modify, based on a further control signal applied thereto, an electric potential distribution in the substrate doping region  116 , e.g. between the control electrode  122  and the readout node  120 . The sensor electrode  130  may provide a capacitive decoupling of the control electrode  122  and the readout node  120  to prevent crosstalk or biasing from the control electrode  122  to the readout node  120 . 
     According to an embodiment, the sensor electrode  130  may be arranged on the first main surface region  110 -A of the semiconductor substrate  110  laterally neighboring the at least one readout node  120 . The sensor electrode  130  may support retaining the collected or directed charge carriers even in case the potential applied to the control electrode  122  is removed. To this end, a constant potential, e.g., a constant positive voltage in case of an n-type substrate doping region  116 , may be applied to the further control electrode  130 . The amplitude of the potential applied to the further control electrode  130  may be less than the amplitude of the reverse voltage applied to the readout node  120  but may be higher than the maximum potential applied to the control electrode  122 . 
     As shown in  FIG. 1B , the time of flight sensor device  100  may optionally comprise the further control electrode  122 - 1  and the further readout node  120 - 1 , wherein a further sensor electrode  130 - 1 , which is separated by an isolating material  132  from the semiconductor substrate  110 , may be arranged on the substrate doping region  116 , e.g. laterally between the further control electrode  122 - 1  and the further readout node  120 - 1 . 
     In case the further control electrode  122 - 1 , the further readout mode  120 - 1  and the further sensor electrode  130 - 1  are arranged in the time of flight sensor device  100 , the above description with respect to the functionality of the sensor electrode  130  in view of the control electrode  122  and the readout node  120  is equally applicable to the further sensor electrode  130 - 1  in view of the further control electrode  122 - 1  and the further readout node  120 - 1 . 
     To summarize, as shown in  FIG. 1B , a sensor electrode  130  may be provided on the first main surface region  110 -A of the semiconductor substrate  110  in combination with the control electrode  122  for redirecting the photo-generated charge carriers to the readout node  120 . 
     Moreover, the further sensor electrode  130 - 1  may be optionally provided on the first main surface region  110 -A of the semiconductor substrate  110  in combination with the further control electrode  122 - 1  for redirecting the photo-generated charge carriers to further readout node  120 - 1 . 
     Moreover, further sensor electrodes  130 - 2 , . . . , may be provided on the first main surface region  110 -A of the semiconductor substrate  110  for redirecting the photo-generated charge carriers to respective readout node  120 ,  120 - 1 . 
     Based on the combination of the at least one control electrode  122 ,  122 - 1  with the at least one sensor electrode  130 ,  130 - 1 ,  130 - 2 , . . . (e.g. a separation gate electrode or photogate electrode), an efficient demodulation of the photo-generated charge carriers in the conversion region  112  is achieved. 
       FIG. 1C  shows a schematic cross sectional view of the time of flight sensor device  100  according to a further embodiment. 
     As shown in  FIG. 1C , the time of flight sensor device comprises the control electrodes  120 ,  120 - 1  and the associated readout nodes  122 ,  122 - 1 . Further, the substrate contact  126  and, optionally, the further substrate contact  126 - 1  are provided. As shown in  FIG. 1C , a further doping region  136  having a p-doping type may be arranged between the control electrodes  120 ,  120 - 1  in the substrate doping region  116  adjacent to the first main surface region  110 -A of the semiconductor substrate  110 . The further doping region  136  forms a surface pinning layer and may be formed by implantation of dopants at the first main surface region  110 -A of the semiconductor substrate  110 . The pinning layer  136  as well as the at least one control electrode  122 ,  122 - 1  may be formed as implanted doped regions, e.g. during the same implanting step. 
     The pinning layer  136  may comprise a p-type doping concentration greater than 1E14 atoms/cm 3 , such as between 1E14 atoms/cm 3  and 1E18 atoms/cm 3 , or between 1E15 atoms/cm 3  and 1E17 atoms/cm 3 , or between 5E15 atoms/cm 3  and 5E16 atoms/cm 3 , for example. 
     Thus, the pinning layer  136  in form of a p-doped resistive region of the semiconductor substrate  110  adjacent to the first main surface region  110 -A and between the two control electrodes (demodulation electrodes)  122 ,  122 - 1  is configured to suppress or at least reduce a leakage current generation in the semiconductor substrate  110  adjacent to the first main surface region  110 -A thereof. The doping concentration of the resistive pinning layer provides for a high resistivity, so that a low or suppressed leakage (shot noise) from electron/hole pair generations at the first main surface region  110 -A of the semiconductor substrate  110 , i.e., at the semiconductor/oxide interface, may be achieved. Thus, the transport of the photo-generated charge carriers (electrons)  114   b  from the conversion region  112  to the respective readout node  120 ,  120 - 1  may be spatially kept away from the regions of the semiconductor substrate  110  directly adjacent to the first main surface region  110 -A. 
       FIG. 2A  shows as schematic cross sectional view of the time of flight sensor device  100  according to a further embodiment. 
     The time of flight sensor device as shown in  FIG. 2A  may be implemented as described with respect to  FIGS. 1A-C , wherein the time of flight sensor device  100  further comprises a buried doping layer  140  in the semiconductor substrate  110 . Thus, the above description with respect to  FIG. 1A-C  is equally applicable to the further embodiments as described below. 
     The time of flight sensor device  100  comprises a semiconductor substrate  110  comprising a conversion region  112  to convert an electromagnetic signal S 1  into photo-generated charge carriers  114   a ,  114   b , and comprising a substrate doping region  116  having a n-doping type, wherein the substrate doping region  116  extends from a first main surface region  110 -A of the semiconductor substrate  110  into the semiconductor substrate  110 . The semiconductor substrate  110  has adjacent to the substrate doping region  116  a p-doped region  110 - 1 . The substrate doping region  116  at least partially forms the conversion region  112  in the semiconductor substrate  110 . At least one readout node  120 ,  120 - 1  arranged in the semiconductor substrate  110  within the substrate doping region  116  and having the n-doping type, wherein the at least one readout node  120 ,  120 - 1  is configured to readout the negative charge carriers  114   b . At least one control electrode  122 ,  122 - 1  is arranged in the substrate doping region  116  of the semiconductor substrate  110  and in the substrate doping region  116  and having the p-doping type. 
     The buried doping layer  140  is arranged in the semiconductor substrate vertically (in the z-direction) below the substrate doping region  116  and the p-doped region  110 - 1  of the semiconductor substrate  110 . The buried doping layer  140  may, for example, extend to the second main surface region  110 -B of the semiconductor substrate  110 . The buried doping layer  140  may be a part of the p-doped region  110 - 1  of the semiconductor substrate  110 . The buried doping layer  140  has a higher p-type doping concentration than the p-doped region  110 - 1  of the semiconductor substrate  110  adjacent to the substrate doping region  116 . 
     As shown in  FIG. 2A , the conversion region  112  extends into the buried doping region  140 , wherein a portion of the buried doping layer  140  contributes to or is part of the conversion region  112  in the semiconductor substrate  110 . 
     According to a further embodiment, the complete buried doping region  140  may be part of the conversion region  112 . 
     According to a further embodiment (not shown in  FIG. 2A ) the buried doping layer  140  may be arranged in the semiconductor substrate  110  in the z-direction directly adjacent to the substrate doping region  116  in the semiconductor substrate  110 . Thus, the buried doping layer  140  may also form the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     As shown in  FIG. 2A , the buried doping layer  140  is formed in the semiconductor substrate  110  vertically below in the depth direction (z-direction) the substrate doping region  116  and, for example, vertically offset in the depth direction of the semiconductor substrate  110  to the substrate doping region  116 . 
       FIG. 2B  shows two exemplary alternatives I, II of the doping profile D 140  of the buried semiconductor layer  140  in the depth direction (=z-direction) of the semiconductor substrate  110 . 
     As shown in  FIG. 2B , according to a first alternative “I” of the doping concentration D, the buried doping layer  140  has a continuously (or monotonically) increasing p-type doping concentration D 140-1  starting at the depth z 1  (=at the plane parallel to the x-y-plane at the depth position z 1 ) with a first doping concentration D 1  up to a maximum doping concentration D 2 . 
     According to a second alternative “II” of the doping concentration D, the buried doping layer  140  provides a graded doping profile in the semiconductor substrate  110  below the substrate doping region  116 . The graded doping profile “II” has a maximum doping concentration D 3  of the p-doping type in an intermediate region at the depth z 2  (=at a plane parallel to the x-y-plane at the depth position z 2 ) of the buried doping layer  140 . Thus, the buried doping layer  140  comprises an exponentially decreasing doping concentration D 140-2  from the intermediate region z 2  of the buried doping layer  140  in the depth direction to the second main surface region  110 -B. 
     The doping concentration D 1  may comprise a p-type doping with a doping concentration up to 1E15 atoms/cm 3  or 1E12 atoms/cm 3 , for example. 
     The doping concentration D 2  may comprise a p-type doping in the range between 1E17 atoms/cm 3  and 1E20 atoms/cm 3 , or between 5E17 atoms/cm 3  and 5E19 atoms/cm 3 , for example. 
     The doping concentration D 3  may comprise a p-type doping in the range between 1.1E15 atoms/cm 3  and 1E20 atoms/cm 3 , or between 5E17 atoms/cm 3  and 5E19 atoms/cm 3 , for example. 
     The doping concentration D 4  may comprise a p-type doping in the range between 1E12 atoms/cm 3  and 1E18 atoms/cm 3 , or between 1E14 atoms/cm 3  and 1E17 atoms/cm 3 , for example. 
     The buried doping layer  140  may comprise typical or minimum thickness t 140  in the range between 1 μm and 30 μm, or between 3 μm and 10 μm, for example. 
     In case, the buried doping layer  140  extends to the second main surface region  110 -B of the semiconductor substrate  110 , the thickness t 140  of the buried doping layer  140  may be up to 200 μm or 300 μm. 
     The buried doping layer  140  according to alternative I or II provides a drift field for minority carriers drifting the photo-generated electrons in the direction of the main surface and towards the substrate doping region  116 . 
     Moreover, the graded doping profile according to alternative II of the buried doping layer  140  provides a electrostatic barrier for photo-generated charge carriers generated in semiconductor regions of the semiconductor substrate  110  extending in the depth direction beyond the depth position z 2  of the buried doping layer  140  having the maximum doping concentration D 3 . Thus, photo-generated charge carriers  114   a ,  114   b  in deeper regions of the semiconductor substrate  110  laterally diffuse and do not affect or negatively influence the demodulation of the photo-generated charge carriers in the substrate doping region  116 . Thus, the p-type buried doping layer  140  effectively suppresses or at least reduces that “slow” (diffusing) charge carriers photo-generated in deeper regions of the semiconductor substrate  110  reach the substrate doping region  116 . 
     Moreover, the at least control electrode  122 ,  122 - 1  in the n-doped substrate doping region  116  provides in combination with the p-doped buried doping layer  140  an effective electrical drift field for the photo-generated charge carriers  114   b  (electrons) in the substrate doping region  116  for a drift-based transport of the photo-generated charge carriers  114   b  to the respective readout node  120 ,  120 - 1 . 
     Based on the p/n-junction between the p-doped buried doping layer  140  (or the p-doped region  110 - 1  of the semiconductor substrate  110 ) and the n-doped substrate doping region  116 , the electrical drift field for the photo-generated charge carriers extend in relatively deep regions of the substrate doping region  116 . 
     To summarize, based on the p-doped buried doping layer  140 , a relatively slow diffusion of photo-generated charge carriers to the surface  110 -A of the semiconductor substrate  110  can be suppressed or at least reduced, which charge carriers would otherwise adversely affect the resulting demodulation contrast. 
     Moreover, the graded doping profile I, II of the buried of the doping layer  140  as shown in  FIG. 2B  provides for an effective drift field for the photo-generated charge carriers  114   b  so that the sensitive volume, i.e. the demodulation volume with photo-generated charge carriers constructively contributing to the sensor output signal, can be increased, and a fast charge carrier extraction can be achieved. 
     Furthermore, according to the graded doping profile of the second alternative shown in  FIG. 2B , slow, e.g. diffusing, charge carriers can be rejected by the downward grading of the doping profile (beyond the depth position z 2 ) towards the substrate backside  110 -B, i.e., the second main surface region  110 -B of the semiconductor substrate  110 . 
     As exemplarily shown in  FIG. 2A-B , the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  may arranged in the substrate doping region  116  of the semiconductor substrate  110  and may have the p doping type, e.g. as an implanted p doping region in the semiconductor substrate  110 . Thus, the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  300  may correspond to the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  (e.g. as described with respect to  FIGS. 1A-C ). 
     Alternatively, the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  may be arranged on the substrate doping region  116  of the semiconductor substrate  110  and may be separated by an insulating material  123  from the semiconductor substrate, e.g. in form of a metallization or polysilicon region  122 ,  122 - 1  with an intermediate insulator layer  123  on the main surface region  110 -A of the semiconductor substrate  110   
       FIG. 3A  shows a schematic cross sectional view of the time of flight sensor device  100  according to a further embodiment. 
     The time of flight sensor device as shown in  FIG. 3A  may be implemented as described with respect to  FIGS. 1A-C ,  2 A-B wherein the time of flight sensor device  100  further comprises a trench structure  150  in the semiconductor substrate  110 . Thus, the above description with respect to  FIGS. 1A-C  and  2 A-B is equally applicable to the further embodiments as described below. 
     The time of flight sensor device  100  comprises a semiconductor substrate  110  comprising a conversion region  112  to convert an electromagnetic signal S 1  into photo-generated charge carriers  114   a ,  114   b , and comprising a substrate doping region  116  having a n-doping type, wherein the substrate doping region  116  extends from a first main surface region  110 -A of the semiconductor substrate  110  into the semiconductor substrate  110 . The semiconductor substrate  110  has adjacent to the substrate doping region  116  a p-doped region  110 - 1 . The substrate doping region  116  at least partially forms the conversion region  112  in the semiconductor substrate  110 . At least one readout node  120 ,  120 - 1  arranged in the semiconductor substrate  110  within the substrate doping region  116  and having the n-doping type, wherein the at least one readout node  120 ,  120 - 1  is configured to readout the photo generated charge carriers  114   b . At least one control electrode  122 ,  122 - 1  is arranged in the substrate doping region  116  of the semiconductor substrate  110  and in the substrate doping region  116  and having the p-doping type. 
     Furthermore, the time of flight sensor device  100  according to the further embodiment comprises a trench structure  150 , which is configured e.g. to suppress or at least reduce cross-talking between adjacent sensor devices  100  within the array. 
     The trench structure  150  extends vertically in the sensor device. According to an embodiment, it presents a spatial arrangement which is symmetrical relative to a central axis of the device. This central axis is for instance defined as a vertical axis (stretching along the z direction) passing through the middle of the segment between the readout nodes  120  and  120 - 1 . 
       FIG. 3I  shows a schematic cross sectional views of the time of flight sensor device  100 , wherein the drawing plane is parallel to the x-y-plane (=perpendicular to the drawing plane of  FIG. 3A ). 
     For instance, the trench structure  150  presents a cross-section along a vertical axis of the sensor device  100  which is generally quadrilateral, such as diamond-shaped, rectangular or square. 
     The trench structure may be arranged so that the sides of its quadrilateral cross-section are parallel to the sides of the sensor device, see  FIG. 3I —options 1 and 2. In such a configuration, the trench structure is for instance arranged in the periphery of the sensor device  100 . The trench structure  150  may consist of a single continuous trench, see  FIG. 3I —option 1. Alternatively, it comprises a plurality of trenches at a distance from each other and which each stretch along a side of the quadrilateral shape of the trench structure  150 , see  FIG. 3I —option 2. 
     Alternatively, the trench structure  150  is rotated relative to the sides of the sensor device  100 , for instance by 45°. For instance, the sides of the cross-section of the trench structure  150  stretch along planes intersecting the middle of a face of the sensor device  100  and the middle of a neighboring face, see  FIG. 3I —options 3 and 4. The trench structure  150  may consist of a single continuous trench, see  FIG. 3I —option 3. Alternatively, it comprises a plurality of trenches at a distance from each other which each stretch along a side of the quadrilateral shape of the trench structure  150 , see  FIG. 3I —option 4. 
     The trench structure  150  is arranged laterally with respect to all or part of the substrate doping region  116 . 
     The trench structure  150  may border at least a portion of the lateral side face  116 -A of the substrate doping layer  116 . In other words, it may be arranged in the semiconductor substrate to at least partially or completely laterally surround or enclose the substrate doping region  116 . 
     In the example of  FIG. 3A , the trench structure  150  is arranged directly adjacent to a lateral side face  116 -A of the substrate doping region  116  over all or part of the height of the substrate doping region  166 . Thus, in the corresponding locations, the substrate doping region  116  may completely extend between the opposing portions of the laterally arranged trench structure  150 . In such a configuration, the at least one substrate contact  126 ,  126 - 1  may be arranged as a back side contact at the second main surface region  110 - b  of the semiconductor substrate  110  or may be laterally arranged in contact with the p-doped region  110 - 1  of the semiconductor substrate  110  (not shown in  FIG. 3A ). 
     The trench structure  150  may form an outer edge of the sensor device  100  over part of the circumference of the later. Alternatively, the trench structure  150  may be buried in the semiconductor substrate  110 . 
     As shown in  FIG. 3A , the trench structure  150  may extend within the semiconductor substrate  110  to or into the p-doped region  110 - 1  of the semiconductor substrate  110  all the way to a bottom surface of the sensor device  100 . Alternatively, it ends at a distance from the bottom surface  110 -B of the sensor device  100 . 
     Moreover, the trench structure  150  may end at a distance from the first main surface region  110 -A. The substrate doping region  116  may thus extend to the lateral edge of the sensor device  100  above the trench structure, and optionally between the trench structure  150  and the first main surface region  110 -A. 
     Alternatively, the trench structure may extend all the way to the first main surface region  110 -A. 
     The inner volume of the trench structure  150  may be filled with a dielectric material or may comprise an empty space (void or gas), for instance so as to cause Total Internal Reflections of the light incident upon the trench structure  150 . 
     In some embodiments, whether that of  FIG. 3A  or any comprising a trench structure  150 , the trench structure  150  may be provided with a liner  156  surrounding all or part of the trench structure  150 . The liner  156  may vertically extend over the entire portion of the trench which is located laterally relative to the substrate doping region  116 . 
     The liner  156  may extend from the p-doping region  110 - 1 . Alternatively, the liner  156  may extend into the p-doping region  110 - 1 . 
     The liner  156  acts as an outer boundary for the corresponding region of the trench. The liner  156  may encapsulate the trench structure  150  in the region in which the liner  156  is present. Alternatively, the liner  156  may only border some of the sides of the trench structure  150 . 
     The liner  156  is for instance configured to act as a pinning layer. 
     The liner  156  is made of p-doped material. The liner  156  may be made of the same material of the p-doping region  110 - 1 , or a different material. 
     The liner  156  may be grown epitaxially, may be formed by out-diffusion (e.g. from an oxide or gas initially arranged in the trench), or by implantation. 
     In the following, a number of different possible implementations of the time of flight sensor device  100  having the trench structure  150  are exemplarily described. The different configurations, in particular in terms of structure and geometry of the trench structure  150 , described in reference to  FIG. 3A  apply to these implementations. 
     In the present description of embodiments, the same or similar elements having the same structure and/or function are provided with the same reference numbers or the same name, wherein a detailed description of such elements will not be repeated for every embodiment. Thus, the above description with respect to  FIG. 3A  is equally applicable to the further embodiments as described below. In the following description, essentially the differences, e.g. additional elements, to the embodiment as shown in  FIG. 3A  and the technical effect(s) resulting therefrom are discussed in detail. 
       FIG. 3B  shows a schematic cross view of a time of flight sensor device according to a further embodiment. 
     As shown in  FIG. 3B , the trench structure  150  is laterally spaced from the substrate doping region  116 , i.e. from the lateral side face  116 -A of the substrate doping region  116 , wherein at least a part of the p-doped region  110 - 1  of the semiconductor substrate  110  extends between the substrate doping region  116  and the trench structure  150 . 
     As shown in  FIG. 3B , the trench structure  150  is laterally spaced from the substrate doping region  116  by means of the p-doped semiconductor region  110 - 1  of the semiconductor substrate, i.e., the trench structure  150  and the substrate doping region  116  are not directly adjacent. Based on this implementation, a crosstalk between neighboring sensor cells of the time of flight sensor device  100  may be suppressed or at least reduced. Furthermore, the distribution of the electrical potential within the substrate doping region  116  may be improved for providing a fast charge carrier transport to the at least one readout node  120 ,  120 - 1 . 
     As shown in  FIG. 3B , the at least one substrate contact  126 ,  126 - 1  may be arranged at the first main surface region  110 -A (front side) or at the second main surface region  110 -B (back side) of the semiconductor substrate  110  in electrical contact with the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     One notes that the embodiment of  FIG. 3B  can be seen as an embodiment of  FIG. 3A  in which the trench structure  150  borders the device  100  at least in part and wherein the liner  156  is only present next to an internal surface of the trench structure  150  and is made of the same material as the region  110 - 1 . 
       FIG. 3C  shows a schematic cross sectional view of the time of flight sensor device  100  according to a further embodiment. 
     The arrangement of the time of flight sensor device  100  of  FIG. 3C  differs from the arrangement of the time of flight sensor device  100  of  FIG. 3A  or  FIG. 3B  in that the p-doped region  110 - 1  of the semiconductor substrate  110  extends below the trench structure  150  in a direction laterally beyond the trench structure  150  and further vertically to the first main surface region  110 -A of the semiconductor substrate to provide a continuous p-doped region  110 - 1  of the semiconductor substrate. Thus, the p-doped region  110 - 1  of the semiconductor substrate  110  extends from the main surface region  110 -A (from an opposing side of the trench structure  150  with respect to the substrate doping region  116 ) vertically into the semiconductor substrate  110  and, below the trench structure  150 , laterally to the region of the semiconductor substrate  110  vertically below the substrate doping region  116 . 
     Thus, the at least one substrate contact  126  may be arranged at the first main surface region  110 -A (front side) of the semiconductor substrate  110  so that no back side processing of the semiconductor substrate (=wafer)  110  is required for providing the at least one substrate contact  126  during manufacturing of the optical time of flight sensor device  100 . 
     In some embodiments, the semiconductor substrate  110  may only extend below the trench structure(s), i.e. not laterally beyond the later. 
       FIG. 3D  shows a schematic cross sectional view of the time of flight sensor device  100  according to a further embodiment. 
     As shown in  FIG. 3D , the trench structure  150  is buried in the semiconductor substrate  110 . To be more specific, the first main surface region  150 -A (e.g. top end) of the trench structure  150  is offset from the first main surface region  110 -A in the depth direction of the semiconductor substrate  110 . In the depth direction, the second main surface region  150 -B (e.g. bottom end) of the trench structure  150  reaches the p-doped region  110 - 1  of the semiconductor substrate. Thus, the second main surface region  150 - b  of the trench structure contacts the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     As shown in  FIG. 3D , a p-doped substrate contact region  154  is arranged in the semiconductor substrate  110 , this substrate contact region  154  having a higher doping concentration than the p-doped region  110 - 1 . The substrate contact region  154  is arranged adjacent to the first main surface region  110 -A of the semiconductor substrate  110 . The substrate contact region  154  may extend at least between the first main surface region  110 -A of the semiconductor substrate and the first main surface region  150 -A of the buried trench structure  150 . Moreover, the upper portion of the substrate doping region  116  laterally extends between the substrate contact region  154 . Thus, the substrate doping region  116  is laterally confined between (the opposing portions of) the substrate contact region  154  and the vertically following trench structure  150 . 
     The p-doped substrate contact region  154  may comprise a p-type doping concentration in the range between 1E14 atoms/cm 3  and 1E20 atoms/cm 3 , or between 1E16 atoms/cm 3  and 1E19 atoms/cm 3 , for example. 
     The implementation of the time of flight sensor device  100  according to embodiment of  FIG. 3D  provides more area on the surface  110 -A of the semiconductor substrate  110  which is available for (optional) active devices (not shown in  FIG. 3D ). 
       FIG. 3E  shows a schematic cross sectional view of the time of flight sensor device according to a further embodiment. 
     As shown in  FIG. 3E , the time of flight sensor device  100  additionally comprises, as described in reference to the arrangement of  FIG. 3A , a vertical liner  156  forming a resistive pinning layer  156  in form of a p-doped resistive region of the semiconductor substrate  110  which is laterally arranged at least between the substrate doping region  116  and the trench structure  150 . The resistive pinning layer  156  may be arranged between the first main surface region  110 -A of the semiconductor substrate  110  and the p-doped region  110 - 1  of the semiconductor substrate  110 . Thus, the resistive pinning layer  156 , which at least partially or completely laterally surrounds or encloses the substrate doping region  116 , may extend from the first main surface region  110 -A to the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     The doping concentration of the pinning layer  156  is greater than 1E14 atoms/cm 3 , or between 1E14 atoms/cm 3  and 1E18 atoms/cm 3 , or between 1E15 atoms/cm 3  and 1E17 atoms/cm 3 , or between 5E15 atoms/cm 3  and 5E16 atoms/cm 3 , for example and, thus, it is higher than the doping concentration of the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     Based on the pinning layer  156 , the leakage (shot noise) from electron/hole pair generation, at the interface (e.g., SI/SIO2 interface) between the semiconductor material of the semiconductor substrate  110  and the isolating (e.g., dielectric) material of the trench structure  150  may be suppressed or at least reduced. 
     One notes that the embodiment of  FIG. 3E  may be seen as an embodiment of  FIG. 3A  in which the liner  156  extends into the region  110 - 1  and is made of a different material relative to the latter, and is only present next to the internal face of the trench structure  150 . 
       FIG. 3F  shows a schematic cross sectional view of the time of flight sensor device  100  according to a further embodiment. 
     The time of flight sensor device as shown in  FIG. 3F  may be implemented as described with respect to  FIGS. 3A-E , so that the above description with respect to  FIG. 3A-E  is equally applicable to the embodiment as described below. 
     As shown in  FIG. 3F , the time of flight sensor device  100  comprises the trench structure  150  (as described with respect to  FIG. 3D ) which is buried in the semiconductor substrate  110 . To be more specific, the first main surface region  150 - 1  of the trench structure  150  is offset from the first main surface region  110 -A in the depth direction of the semiconductor substrate  110 . In the depth direction, the second main surface region  150 -B of the trench structure  150  reaches the p-doped region  110 - 1  of the semiconductor substrate. Thus, the second main surface region  150 -B of the trench structure contacts the p-doped region  110 - 1  of the semiconductor substrate  110 . As further shown in  FIG. 3F , the p-doped substrate contact region  154  is arranged in the semiconductor substrate  110  adjacent to the first main surface region  110 -A. The substrate contact region  154  may extend between the first main surface region  110 -A of the semiconductor substrate and the first main surface region  150 -A of the buried trench structure  150 . 
     As shown in  FIG. 3F , the time of flight sensor device  100  further comprises the pinning layer  156  (as described with respect e.g. to  FIG. 3E ) in form of a p-doped resistive region of the semiconductor substrate  110  which is laterally arranged at least between the substrate doping region  116  and the trench structure  150 . 
     As shown in  FIG. 3F , the time of flight sensor device  100  further comprises the buried doping later  140  (as described with respect to  FIG. 2A-B ) which is arranged in the semiconductor substrate vertically (in the z-direction) below the substrate doping region  116  and the p-doped region  110 - 1  of the semiconductor substrate  110 . The buried doping layer  140  may, for example, extend to the second main surface region  110 -B of the semiconductor substrate  110 . The buried doping layer  140  may be a part of the p-doped region  110 - 1  of the semiconductor substrate  110 . The buried doping layer  140  has a higher p-type doping concentration than the p-doped region  110 - 1  of the semiconductor substrate  110  adjacent to the substrate doping region  116 . 
     According to a further embodiment (not shown in  FIG. 2A ) the buried doping layer  140  may be arranged in the semiconductor substrate  110  in the z-direction directly adjacent to the substrate doping region  116  in the semiconductor substrate  110 . Thus, the buried doping layer  140  may form the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     As shown in  FIG. 3F , the time of flight sensor device  100  further comprises the sensor electrode  130 , e.g. a so-called separation gate or photogate (modulation gate), (as described with respect to  FIG. 1B ) which is optionally separated by an isolating material  132  form the semiconductor substrate  110  and may be arranged on the first main surface region  110 -A of the semiconductor substrate  110 . As shown in  FIG. 3F , the sensor electrode  130  may be arranged in a lateral direction between the control electrode  122  and the readout node  120 . Moreover, the further sensor electrode  130 - 1  may be optionally provided on the first main surface region  110 -A of the semiconductor substrate  110  in combination with the further control electrode  122 - 1 . Moreover, the further sensor electrode(s)  130 - 2 , . . . , may be provided on the first main surface region  110 -A of the semiconductor substrate  110  for redirecting the photo-generated charge carriers to respective readout node  120 ,  120 - 1 . 
     Based on the implementation of the time of flight sensor device  100  according  FIG. 3F , a very efficient demodulation of the photo-generated charge carriers in the conversion region  112  is achieved. 
       FIG. 3G  shows a schematic cross sectional view of the time of flight sensor device  100  according to a further embodiment. 
     As shown in  FIG. 3G  (when compared to the implementation of  FIG. 3A ), the trench material filling the trench structure  150  comprises charges  152  (negative charge carriers or negatively charged regions) neighboring the lateral main surface region  150 -C of the trench structure  150 . The dielectric trench filling material may comprise, for example, AL 2 0 3 , wherein the AL 2 O 3  material may comprise a layer-like structure. The negative charge carriers  152  may attract positive charge carries (holes)  155  from the substrate material of the semiconductor substrate  110  at the lateral region  116 -A of the substrate doping region  116 . More precisely, negative charges  152  are stored in the dielectric material of the trench structure  150  which leads to an accumulation of holes  155  at the lateral region  116 -A of the substrate doping region  116  bordering to the trench structure  150 . 
     The accumulation of holes  155  at the lateral region  116 -A of the substrate doping region  116  influences the electrical equipotential lines in the substrate doping region  116  which results in a more efficient demodulation of the photo-generated charge carriers  114   b . Furthermore, the leakage (shot noise) from an electron/hole pair generation at the interface between the semiconductor material of the semiconductor substrate  110  and the dielectric material of the trench structure  150  may be suppressed or at least reduced. These results are achievable with a minimum space requirement based on the implementation of the time of flight sensor device  100  according to the embodiment of  FIG. 3G . 
       FIG. 3H  shows a schematic cross sectional view of the time of flight sensor device  100  according to a further embodiment. 
     The arrangement of the time of flight sensor device  100  of  FIG. 3H  differs from the arrangement of the time of flight sensor device  100  of  FIG. 3F  in that, instead of the pinning layer  156 , the trench material filling the trench structure  150  comprises charges  152  (negative charge carriers or negatively charged regions) neighboring to the lateral main surface region  150 -C of the trench structure  150 . 
     As shown in  FIG. 3H , the time of flight sensor device  100  comprises the trench structure  150  which is buried in the semiconductor substrate  110 . 
     The time of flight sensor device  100  further comprises the buried doping later  140  which is arranged in the semiconductor substrate vertically (in the z-direction) below the substrate doping region  116  and the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     Moreover, the at least one additional sensor electrode(s)  130 ,  130 - 1 ,  130 - 2 , . . . , e.g. a so-called separation gate or photogate (modulation gate), may be provided on the first main surface region  110 -A of the semiconductor substrate  110  for redirecting the photo-generated charge carriers to respective readout node  120 ,  120 - 1 . 
     Based on the implementation of the time of flight sensor device  100  according  FIG. 3F , a very efficient demodulation of the photo-generated charge carriers in the conversion region  112  is achieved. 
     As exemplarily shown in  FIG. 3A-H , the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  may arranged in the substrate doping region  116  of the semiconductor substrate  110  and may have the p doping type, e.g. as an implanted p doping region in the semiconductor substrate  110 . Thus, the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  300  may correspond to the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  (e.g. as described with respect to  FIGS. 1A-C ). 
     Alternatively, the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  may be arranged on the substrate doping region  116  of the semiconductor substrate  110  and may be separated by an insulating material  123  from the semiconductor substrate, e.g. in form of a metallization or polysilicon region  122 ,  122 - 1  with an intermediate insulator layer  123  on the main surface region  110 -A of the semiconductor substrate  110   
       FIG. 4  shows a schematic cross sectional view of the time of flight sensor device  200  according to a further embodiment. 
     According to another embodiment, a time of flight sensor device  200  comprises a semiconductor substrate  110 . The semiconductor substrate  110  comprises a conversion region  112  to convert an electromagnetic signal S 1  into photo-generated charge carriers  114   a ,  114   b . The semiconductor substrate  110  further comprises a substrate doping region  116  having a n doping type, wherein the substrate doping region  116  extends from a first main surface region  110 -A of the semiconductor substrate  110  into the semiconductor substrate  110  (in the depth direction or z direction). 
     The semiconductor substrate  110  has adjacent to the substrate doping region  116  a p-doped region  110 - 1 , i.e. the remaining region  110 - 1  of the semiconductor substrate  110 - 1  adjacent to the substrate doping region  116  has a p-doping type. The substrate doping region  116  at least partially forms the conversion region  112  in the semiconductor substrate. A readout node  120  is arranged in the semiconductor substrate  110  within the substrate doping region  116  and has the n doping type e.g. with a higher doping concentration than the substrate doping region  116 . The readout node  120  is configured to readout the photo generated charge carriers  114   b , e.g., the photo-generated electrons. 
     A control electrode  122  is arranged in or on the substrate doping region of the semiconductor substrate. A buried doping layer  140  in the semiconductor substrate having a higher concentration of the p doping type than p-doped region  110 - 1  of the semiconductor substrate  110  is arranged adjacent to the substrate doping region  116 , wherein the buried doping layer  140  is formed in the semiconductor substrate  110  and vertically below the substrate doping region  116  in the semiconductor substrate  110 . 
     As exemplarily shown in  FIG. 4 , the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  200  may be arranged on the substrate doping region  116  of the semiconductor substrate  110  and may be separated by an insulating material  123  from the semiconductor substrate  110 , e.g. in form of a metallization or polysilicon region  122 ,  122 - 1  with an intermediate insulator layer  123  on the main surface region  110 -A of the semiconductor substrate  110 . 
     Alternatively, the control electrode(s)  122 ,  122 - 1  may arranged in the substrate doping region  116  of the semiconductor substrate  110  and may have the p doping type, e.g. as an implanted p doping region in the semiconductor substrate  110 . Thus, the control electrode(s)  122 ,  122 - 1  may correspond to the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  (e.g. as described with respect to  FIGS. 1A-C  and  FIGS. 2A-B ). 
     According to an embodiment, the buried doping layer  140  of the time of flight sensor device  200  of  FIG. 4  structurally and functionally corresponds to the buried doping layer  140  of the time of flight sensor device  100  of  FIG. 2A-B , wherein the doping concentration of the buried doping layer  140  of  FIG. 4  is exemplarily shown in  FIG. 2B  as a schematic plot having the two exemplary alternatives I, II of the doping profile D 140  of the buried semiconductor layer  140  in the depth direction (=z-direction) of the semiconductor substrate  110 . Thus, the above description of the structure and functionality of the buried doping layer  140  of the time of flight sensor device  100  (e.g. with respect to  FIG. 2A-B ) is equally applicable to the embodiment of the time of flight sensor device  200  as described with respect to  FIG. 4 . 
     According to a further embodiment, the time of flight sensor device  200  may comprise a trench structure (not shown in  FIG. 4 ) which is arranged laterally with respect to the substrate doping region  116  and extends vertically with respect to the first main surface region  110 -A of the semiconductor substrate  110  into the semiconductor substrate  110 . Thus, the above description of the structure and functionality of the trench structure  150  of the time of flight sensor device  100  (e.g. with respect to  FIG. 3A-H ) is equally applicable to the embodiment of the time of flight sensor device  200  as described with respect to  FIG. 4 . 
     According to an embodiment, the TOF sensor device  100  may optionally comprise a further control electrode  122 - 1  to optionally provide a pair of control electrodes  122 ,  122 - 1  and a further readout node  120 - 1  to optionally provide a pair of readout nodes  120 ,  120 - 1 . 
     The optional further control electrode  122 - 1  may be also arranged in or on the substrate doping region  116  of the semiconductor substrate  110 . As shown in  FIG. 4 , the further control electrode  122 - 1  may also be arranged in the conversion region  112  adjacent to the first main surface region  110 -A of the semiconductor substrate  110 . The further control electrode  122 - 1  may be formed as implanted doping region in the semiconductor substrate  110 . The further control electrode  122 - 1  may comprise the same p-type doping concentration as the control electrode  122 , for example. 
     Alternatively, the further control electrode  122 - 1  may be arranged on the substrate doping region  116  of the semiconductor substrate  110  and is separated by an insulating material  123  from the semiconductor substrate, e.g. in form of a metallization or polysilicon region  122 - 1  with an intermediate insulator layer  123  on the main surface region  110 -A of the semiconductor substrate  110 . 
     The optional further readout node  120 - 1  is arranged in the semiconductor substrate  110  within the substrate doping region  116  and has the n-doping type, e.g. with a higher doping concentration than the substrate doping region  116 . The further readout node  120 - 1  is also configured to readout the photo-generated charge carries  114   b , e.g., the photo-generated electrons. The further readout node  120 - 1  may be formed as further implanted doping region in the semiconductor substrate  110 . The further readout node  120 - 1  may comprise the same n-type doping concentration as the readout node  120 . 
     Thus, the above description of the structure and functionality of the further readout node  120 - 1  and the further control electrode  122 - 1  of the time of flight sensor device  100  (e.g. with respect to  FIG. 1A-B ) is equally applicable to the embodiment of the time of flight sensor device  200  as described with respect to  FIG. 4 . 
     As shown in  FIG. 4 , a further substrate contact  126 - 1  may be optionally provided at the p-doped region  110 - 1  of the semiconductor substrate  110 . In case, the further substrate contact  126 - 1  is arranged, the above description of the structure and functionality of the substrate contact  126 - 1  of the time of flight sensor device  100  is equally applicable to the further substrate contact  126 - 1  of the time of flight sensor device  100 . 
       FIGS. 5A-B  show schematic cross sectional views of the time of flight sensor device according to further embodiments. 
     The time of flight sensor device  200  as shown in  FIG. 5A  may be implemented as described with respect to  FIG. 4  wherein the time of flight sensor device  200  may further comprise a trench structure  150  in the semiconductor substrate  110  which is arranged laterally with respect to the substrate doping region  116  and extends vertically with respect to the first main surface region  110 -A of the semiconductor substrate  110  into the semiconductor substrate  110 . The trench structure  150  may be buried in the semiconductor substrate  110  Thus, the above description of the structure and functionality of the trench structure  150  of the time of flight sensor device  100  (e.g. with respect to  FIG. 3A-H ) is equally applicable to the embodiment of the time of flight sensor device  200  as described with respect to  FIG. 4 . 
     As exemplarily shown in  FIG. 5A , the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  200  may be arranged on the substrate doping region  116  of the semiconductor substrate  110  and may be separated by an insulating material  123  from the semiconductor substrate, e.g. in form of a metallization or polysilicon region  122 ,  122 - 1  with an intermediate insulator layer  123  on the main surface region  110 -A of the semiconductor substrate  110 . Alternatively, the control electrode(s)  122  may arranged in the substrate doping region  116  of the semiconductor substrate  110  and may have the p doping type, e.g. as an implanted p doping region in the semiconductor substrate  110 . Thus, the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  200  may correspond to the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  (e.g. as described with respect to  FIGS. 1A-C  and  FIGS. 2A-B ). 
     As shown in  FIG. 5A , the trench structure  150  is buried in the semiconductor substrate  110 , wherein the p-doped substrate contact region  154  is arranged in the semiconductor substrate  110  adjacent to the first main surface region  110 -A of the semiconductor substrate  110  and extends at least between the first main surface region  110 -A of the semiconductor substrate and the first main surface region  150 -A of the buried trench structure  150 . The second main surface region  150 - b  of the trench structure contacts the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     As shown in  FIG. 5A , the time of flight sensor device  200  may further comprise the pinning layer  156  in form of a p-doped resistive region of the semiconductor substrate  110  which is laterally arranged between the substrate doping region  116  and the trench structure  150 . The time of flight sensor device  200  may further comprise the buried doping later  140  which is arranged in the semiconductor substrate vertically below the substrate doping region  116  of the semiconductor substrate  110 . The buried doping layer  140  may be a part of the p-doped region  110 - 1  of the semiconductor substrate  110 . The buried doping layer  140  has a higher p-type doping concentration than the p-doped region  110 - 1  of the semiconductor substrate  110  adjacent to the substrate doping region  116 . 
     As shown in  FIG. 5A , the time of flight sensor device  200  further comprises the sensor electrode  130 , e.g. a so-called separation gate or photogate (modulation gate), (as described with respect to  FIG. 1B ) which is optionally separated by an isolating material  132  form the semiconductor substrate  110  and may be arranged on the first main surface region  110 -A of the semiconductor substrate  110 . As shown in  FIG. 5A , the sensor electrode  130  may be arranged in a lateral direction between the control electrode  122  and the readout node  120 . Moreover, the further sensor electrode  130 - 1  may be optionally provided on the first main surface region  110 -A of the semiconductor substrate  110  in combination with the further control electrode  122 - 1 . Moreover, the further sensor electrode(s)  130 - 2 , . . . , may be provided on the first main surface region  110 -A of the semiconductor substrate  110  for redirecting the photo-generated charge carriers to respective readout node  120 ,  120 - 1 . 
     Based on the implementation of the time of flight sensor device  200  according  FIG. 5A , a very efficient demodulation of the photo-generated charge carriers in the conversion region  112  is achieved. 
       FIG. 5B  shows a schematic cross sectional view of the time of flight sensor device  200  according to a further embodiment. The arrangement of the time of flight sensor device  200  of  FIG. 5B  differs from the arrangement of the time of flight sensor device  200  of  FIG. 5A  in that, instead of the pinning layer  156 , the trench material filling the trench structure  150  comprises charges  152  (negative charge carriers or negatively charged regions) neighboring to the lateral main surface region  150 -C of the trench structure  150 . Thus, the above description of the structure and functionality of the trench structure  150  of the time of flight sensor device  100  (e.g. with respect to  FIG. 3H ) is equally applicable to the embodiment of the time of flight sensor device  200  as described with respect to  FIG. 5B . 
     As shown in  FIG. 5B , the time of flight sensor device  200  comprises the trench structure  150  which is buried in the semiconductor substrate  110 . The time of flight sensor device  200  further comprises the buried doping later  140  which is arranged in the semiconductor substrate vertically (in the z-direction) below the substrate doping region  116  and the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     As exemplarily shown in  FIG. 5B , the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  200  may be arranged on the substrate doping region  116  of the semiconductor substrate  110  and may be separated by an insulating material  123  from the semiconductor substrate, e.g. in form of a metallization or polysilicon region  122 ,  122 - 1  with an intermediate insulator layer  123  on the main surface region  110 -A of the semiconductor substrate  110 . Alternatively, the control electrode(s)  122 ,  122 - 1  may arranged in the substrate doping region  116  of the semiconductor substrate  110  and may have the p doping type, e.g. as an implanted p doping region in the semiconductor substrate  110 . Thus, the control electrode(s)  122 ,  122 - 1  may correspond to the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  (e.g. as described with respect to  FIGS. 1A-C  and  FIGS. 2A-B ). 
     Moreover, the at least one additional sensor electrode(s)  130 ,  130 - 1 ,  130 - 2 , . . . , e.g. a so-called separation gate or photogate (modulation gate), may be provided on the first main surface region  110 -A of the semiconductor substrate  110  for redirecting the photo-generated charge carriers to respective readout node  120 ,  120 - 1 . 
       FIG. 6  shows a schematic cross sectional view of a time of flight sensor device  300  according to further embodiments. 
     According to another embodiment, the time of flight sensor device  300  comprises a semiconductor substrate  110 . The semiconductor substrate  110  comprises a conversion region  112  to convert an electromagnetic signal S 1  into photo-generated charge carriers  114   a ,  114   b . The semiconductor substrate  110  further comprises a substrate doping region  116  having a n doping type, wherein the substrate doping region  116  extends from a first main surface region  110 -A of the semiconductor substrate  110  into the semiconductor substrate  110  (in the depth direction or z direction). 
     The semiconductor substrate  110  has adjacent to the substrate doping region  116  a p-doped region  110 - 1 , i.e. the remaining region  110 - 1  of the semiconductor substrate  110 - 1  adjacent to the substrate doping region  116  has a p-doping type. The substrate doping region  116  at least partially forms the conversion region  112  in the semiconductor substrate. 
     A readout node  120  is arranged in the semiconductor substrate  110  within the substrate doping region  116  and has the n doping type e.g. with a higher doping concentration than the substrate doping region  116 . The readout node  120  is configured to readout the photo generated charge carriers  114   b , e.g., the photo-generated electrons. 
     A control electrode  122  is arranged in or on the substrate doping region of the semiconductor substrate. 
     The time of flight sensor device  300  further comprises a trench structure  150  in the semiconductor substrate  110  which is arranged laterally with respect to the substrate doping region  116  and extends vertically with respect to the first main surface region  110 -A of the semiconductor substrate  110  into the semiconductor substrate  110 . 
     Thus, the above description of the different implementations of the time of flight sensor device  100  regarding the structure and functionality of the trench structure  150  (e.g. with respect to  FIG. 3A-H ) is equally applicable to the time of flight sensor device  300  as described with respect to  FIG. 6 . 
     As exemplarily shown in  FIG. 6 , the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  300  may be arranged on the substrate doping region  116  of the semiconductor substrate  110  and may be separated by an insulating material  123  from the semiconductor substrate, e.g. in form of a metallization or polysilicon region  122 ,  122 - 1  with an intermediate insulator layer  123  on the main surface region  110 -A of the semiconductor substrate  110 . 
     Alternatively, the control electrode(s)  122 ,  122 - 1  may arranged in the substrate doping region  116  of the semiconductor substrate  110  and may have the p doping type, e.g. as an implanted p doping region in the semiconductor substrate  110 . Thus, the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  300  may correspond to the control electrode(s)  122 ,  122 - 1  of the time of flight sensor device  100  (e.g. as described with respect to  FIGS. 1A-C  and  FIGS. 2A-B ). 
     According to a further embodiment, the trench structure  150  may be laterally spaced from the substrate doping region  116 , wherein at least a part of the p-doped region  110 - 1  of the semiconductor substrate  110  is arranged between the substrate doping region  110 - 1  and the trench structure  150  (see also  FIG. 3B  and the associated description, for example). 
     According to a further embodiment, the trench structure  150  may be arranged directly adjacent to the substrate doping region  116  (see also  FIG. 3A  and the associated description, for example). 
     According to a further embodiment, the time of flight sensor device  300  may further optionally comprise a trench pinning layer  156  (not shown in  FIG. 6 ) in form of a p doped resistive region of the semiconductor substrate  110 , wherein the trench pinning layer  156  is arranged adjacent to the trench structure  150  and at least between the trench structure  150  and the substrate doping region  116  and extends to the p-doped region  110 - 1  of the semiconductor substrate  110  (see also  FIG. 3E-F  and the associated description, for example). 
     According to a further embodiment, a further doping region (=pinning layer)  136  having a p-doping type may be optionally arranged between the control electrodes  122 ,  122 - 1  in the substrate doping region  116  adjacent to the first main surface region  110 -A of the semiconductor substrate  110  (see also  FIG. 1C  and the associated description, for example). 
     According to a further embodiment, the trench structure  150  comprises a trench dielectric material with stored charge carriers  152  in the trench dielectric material adjacent to the substrate doping region  116  (see also  FIG. 3G-H  and the associated description, for example). 
     According to a further embodiment, the trench structure  150  may be buried in the semiconductor substrate  110  and extends in the p-doped region  110 - 1  of the semiconductor substrate  110  (see also  FIG. 3D, 3F, 3H  and the associated description, for example). 
     According to a further embodiment, the time of flight sensor device  300  may further comprise a substrate contact region  154  having the p doping type in the semiconductor substrate  110  and adjacent to the first main surface region  110  of the semiconductor substrate  110  (see also  FIG. 3D, 3F, 3H  and the associated description, for example). 
     According to an embodiment, the substrate contact region  154  is arranged between the first main surface region  110 -A of the semiconductor substrate  110  and the buried trench structure  150  (see also  FIG. 3D, 3F, 3H  and the associated description, for example). 
     According to a further embodiment, the trench structure  150  extends between the substrate contact region  154  and a buried doping layer  140  (see also  FIG. 3F, 3H  and the associated description, for example). The buried doping layer  140  in the semiconductor substrate having a higher concentration of the p doping type than p-doped region  110 - 1  of the semiconductor substrate  110  may be arranged adjacent to the substrate doping region  116 , wherein the buried doping layer  140  is formed in the semiconductor substrate  110  and vertically below the substrate doping region  116  in the semiconductor substrate  110 . Thus, the above description of the structure and functionality of the buried doping layer  140  of the time of flight sensor device  100  (e.g. with respect to  FIG. 2A-B ) is equally applicable to the embodiment of the time of flight sensor device  300  as described with respect to  FIG. 6 . 
       FIG. 7  shows an exemplary schematic circuit diagram of a time of flight sensor arrangement according to a further embodiment. 
     According to another embodiment, a time of flight sensor arrangement  400  comprises: a plurality of pixels respectively having one of time of flight sensor devices  100 ,  200 ,  300 , wherein the pixels are arranged in an array  410  (e.g. a n×m array, with n≥2 (2, 3, 4, 5, . . . ) and m≥2 (2, 3, 4, 5, . . . ), and a controller  420  for providing a control signal C xm  to the respective control electrode(s)  122 ,  122 - 1 . 
     The optical time of flight sensor device  100  may be configured to detect a time of flight of the electromagnetic signal S 0 , S 1 , which enters the conversion region  112 . To this end, the optical time of flight sensor device  100  may further comprise a controller which may be configured to apply a varying potential to the control electrode(s)  122 ,  122 - 1 , to generate electrical potential distributions in the substrate doping region  116  and the conversion region  112 , by which, the photo-generated charge carriers in the conversion region  112  are directed in different directions, e.g. towards the read-out region(s)  122 ,  122 - 1 , dependent on the time of flight of the electromagnetic signal S 0 , S 1 , which enters the conversion region. 
     The varying potential, applied by the controller to the control electrode(s), is a demodulation signal having a fixed phase relationship with a modulation signal with which the electromagnetic signal S 0  is modulated. 
     The controller  420  may be further configured to determine the time of flight of the electro-magnetic signal S 0 , S 1  based on a relationship of the amount of charge carriers collected at the first readout node  120  and/or the amount of charge carriers collected at the second readout node  120 - 1 . In embodiments, the controller  420  may be formed of any appropriate integrated circuit and may be integrated with the optical time of flight sensor device  100 . In embodiments, the controller may be provided by an integrated circuit separate from the semiconductor substrate of the optical sensor device. In embodiments, at least parts of the controller may be formed by a microprocessor or an FPGA (Field Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit). 
     Additional embodiments and aspects are described which may be used alone or in combination with the features and functionalities described herein. 
     According to an embodiment, a time of flight sensor device  100  comprises: a semiconductor substrate  110  comprising a conversion region  112  to convert an electromagnetic signal S into photo-generated charge carriers  114   a ,  114   b , and comprising a substrate doping region  116  having a n doping type, wherein the substrate doping region  116  extends from a first main surface region  110 -A of the semiconductor substrate  110  into the semiconductor substrate  110 , wherein the semiconductor substrate  110  has adjacent to the substrate doping region  116  a p doped region  110 - 1 , and wherein the substrate doping region  116  at least partially forms the conversion region  112  in the semiconductor substrate  110 , a readout node  120  arranged in the semiconductor substrate  110  within the substrate doping region  116  and having the n-doping type, wherein the readout node  120  is configured to readout the photo generated charge carriers  114   b ; and a control electrode  122  arranged in the substrate doping region  116  of the semiconductor substrate  110  and in the substrate doping region  116  and having the p-doping type. 
     According to one aspect, the conversion region  112  vertically extends beyond the substrate doping region  116  in the semiconductor substrate  110 . 
     According to another aspect, the time of flight sensor device  100  further comprises: a sensor electrode  130  which is separated by an isolating material  132  from the semiconductor substrate  130 , wherein the sensor electrode  130  is configured to modify an electric potential distribution in the substrate doping region  116 . 
     According to another aspect, the time of flight sensor device  100  further comprises: a further control electrode  122 - 1  arranged in the substrate doping region  116  of the semiconductor substrate  110  and having the p-doping type, and a resistive pinning layer  136  in form of a p doped resistive region of the semiconductor substrate  110 , wherein the resistive pinning layer  136  is arranged in the semiconductor substrate  110  adjacent to the first main surface region  110 -A and between the two control electrodes  122 ,  122 - 1 . 
     According to another aspect, the time of flight sensor device  100  further comprises: a buried doping layer  140  in the semiconductor substrate  110  having a higher concentration of the p doping type than the p-doped region  110 - 1  of the semiconductor substrate  110  adjacent to the substrate doping region  116 , wherein the buried doping layer  140  is formed vertically below the substrate doping region  116  in the semiconductor substrate  110 . 
     According to another aspect, the buried doping layer  140  provides a graded doping profile in the semiconductor substrate  110  having a maximum doping concentration of the p doping type in an intermediate region  140 - 1  of the buried doping layer. 
     According to another aspect, the time of flight sensor device  100  further comprises: a trench structure  150  which is arranged laterally with respect to the substrate doping region  116  and extends vertically with respect to the first main surface region  110 - a  of the semiconductor substrate  110  in the semiconductor substrate  110 . 
     According to another aspect, the trench structure  150  is arranged directly adjacent to the substrate doping region  116 . 
     According to another aspect, the trench structure  150  is laterally spaced from the substrate doping region  116 , wherein at least a part of the p-doped region  110 - 1  of the semiconductor substrate  110  is arranged between the substrate doping region  116  and the trench structure  150 . 
     According to another aspect, the time of flight sensor device  100  further comprises: a trench pinning layer  156  in form of a p doped resistive region of the semiconductor substrate  110 , wherein the trench pinning layer  156  is arranged adjacent to the trench structure  150  and is arranged at least between the trench structure  150  and the substrate doping region  116  and extends to the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     According to another aspect, the trench structure  150  comprises a trench dielectric material with stored charge carriers in the trench dielectric material adjacent to the substrate doping region  116 . 
     According to another aspect, the trench structure  150  is buried in the semiconductor substrate  110  and reaches in the depth direction the p-doped region  110 - 1  of the semiconductor substrate  110 . 
     According to another aspect, the time of flight sensor device  100  further comprises: a substrate contact region  154  having the p doping type in the semiconductor substrate  110  and adjacent to the first main surface region  110 -A of the semiconductor substrate  110 . 
     According to another aspect, the substrate contact region  116  is arranged between the first main surface region  110 -A of the semiconductor substrate  110  and the trench structure  150 . 
     According to another aspect, the buried trench structure  150  extends between the substrate contact region  154  and the buried doping layer  140 . 
     According to another embodiment, a time of flight sensor device  200  comprises: a semiconductor substrate comprising a conversion region to convert an electromagnetic signal into photo-generated charge carriers, and comprising a substrate doping region having a n doping type, wherein the substrate doping region extends from a first main surface region of the semiconductor substrate into the semiconductor substrate, wherein the semiconductor substrate has adjacent to the substrate doping region a p-doped region  110 - 1 , and wherein the substrate doping region at least partially forms the conversion region in the semiconductor substrate, a readout node arranged in the semiconductor substrate within the substrate doping region and having the n doping type, wherein the readout node is configured to readout the photo generated charge carriers, a control electrode arranged in or on the substrate doping region of the semiconductor substrate, and a buried doping layer  140  in the semiconductor substrate having a higher concentration of the p doping type than p-doped region of the semiconductor substrate adjacent to the substrate doping region, wherein the buried doping layer is formed in the semiconductor substrate and vertically below the substrate doping region  116  in the semiconductor substrate  110 . 
     According to one aspect, the control electrode is arranged in in the substrate doping region and having the p doping type, or the control electrode is arranged on the substrate doping region of the semiconductor substrate and is separated by an isolating material from the semiconductor substrate. 
     According to another aspect, the buried doping layer provides a graded doping profile in the semiconductor substrate having a maximum doping concentration of the p doping type in an intermediate region of the buried doping layer. 
     According to another aspect, the time of flight sensor device further comprises: a trench structure which is arranged laterally with respect to the substrate doping region and extends vertically with respect to the first main surface region of the semiconductor substrate in the semiconductor substrate. 
     According to another embodiment, a time of flight sensor device  300  comprises: a semiconductor substrate comprising a conversion region to convert an electromagnetic signal into photo-generated charge carriers, and comprising a substrate doping region having a n doping type, wherein the substrate doping region extends from a first main surface region of the semiconductor substrate into the semiconductor substrate, wherein the semiconductor substrate  110  has adjacent to the substrate doping region  116  a p-doped region  110 - 1 , and wherein the substrate doping region at least partially forms the conversion region in the semiconductor substrate, a readout node arranged in the semiconductor substrate within the substrate doping region and having the n doping type, wherein the readout node is configured to readout the photo generated charge carriers; a control electrode arranged in or on the substrate doping region of the semiconductor substrate, and a trench structure which is arranged laterally with respect to the substrate doping region and which extends vertically with respect to the first main surface region of the semiconductor substrate in the semiconductor substrate. 
     According to one aspect, the control electrode is arranged in the substrate doping region and having the p doping type, or wherein the control electrode is arranged on the substrate doping region of the semiconductor substrate and is separated by an isolating material from the semiconductor substrate. 
     According to another aspect, the trench structure is arranged directly adjacent to the substrate doping region. 
     According to another aspect, the trench structure is laterally spaced from the substrate doping region, wherein the p-doped region  110 - 1  of the semiconductor substrate  110  is arranged between the substrate doping region and the trench structure. 
     According to another aspect, the time of flight sensor device  300  further comprises: a trench pinning layer in form of a p doped resistive region of the semiconductor substrate, wherein the trench pinning layer is arranged adjacent to the trench structure and at least between the trench structure and the substrate doping region and extends to the p-doped region  110 - 1  of the semiconductor substrate. 
     According to another aspect, the trench structure comprises a trench dielectric material with stored charge carriers in the trench dielectric material adjacent to the substrate doping region. 
     According to another aspect, the trench structure is buried in the semiconductor substrate and extends in the p-doped region  110 - 1  of the semiconductor substrate. 
     According to another aspect, the time of flight sensor device  300  further comprises: a substrate contact region having the p doping type in the semiconductor substrate and adjacent to the first main surface region of the semiconductor substrate. 
     According to another aspect, the substrate contact region is arranged between the first main surface region of the semiconductor substrate and the trench structure. 
     According to another aspect, the trench structure extends between the substrate contact region and the buried doping layer  140 . 
     According to another embodiment, a time of flight sensor arrangement  400  comprises: a plurality of the time of flight sensor devices  100 ,  200 ,  300 , wherein the time of flight sensor devices  100 ,  200 ,  300  are arranged in an array, and a controller for providing a control signal to the control electrode. 
     Although some aspects have been described as features in the context of an apparatus it is clear that such a description may also be regarded as a description of corresponding features of a method. Although some aspects have been described as features in the context of a method, it is clear that such a description may also be regarded as a description of corresponding features concerning the functionality of an apparatus. 
     In the foregoing Detailed Description, it can be seen that various features are grouped together in examples for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed examples require more features than are expressly recited in each claim. Rather, as the following claims reflect, subject matter may lie in less than all features of a single disclosed example. Thus the following claims are hereby incorporated into the Detailed Description, where each claim may stand on its own as a separate example. While each claim may stand on its own as a separate example, it is to be noted that, although a dependent claim may refer in the claims to a specific combination with one or more other claims, other examples may also include a combination of the dependent claim with the subject matter of each other dependent claim or a combination of each feature with other dependent or independent claims. Such combinations are proposed herein unless it is stated that a specific combination is not intended. Furthermore, it is intended to include also features of a claim to any other independent claim even if this claim is not directly made dependent to the independent claim. 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present embodiments. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that the embodiments be limited only by the claims and the equivalents thereof.