Patent Publication Number: US-2022216180-A1

Title: Mixed exposure for large die

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This patent application claims priority to U.S. Utility patent application Ser. No. 17/075,489, filed Oct. 20, 2020, which is fully incorporated herein by reference. 
     BACKGROUND 
     In microelectronic devices, electronic circuits are fabricated on a wafer of semiconductor material, such as silicon. The wafer with electronic circuits may be bonded to one or more other wafers, bonded to individual dies, or itself diced (singulated) into numerous dies, each die containing a copy of the circuit. Each die that has a functional integrated circuit is known as a microchip or “chip.” When specific functions from a library of functions are assigned to individual chips, or when a large monolithic chip is emulated by a collection of smaller chips, these smaller chips, or chips with specific or proprietary functions, may be referred to as “chiplets.” As used herein, unless otherwise indicated, chiplet means a complete subsystem (intellectual property core) (IP core), a reusable unit of logic, memory and/or other circuitry, on a single die. A library of chiplets may provide routine or well-established IP-block functions. 
     Large composite base dies, e.g., interposers, of microelectronic devices generally include multiple chiplets made up of multiple layers. The large composite dies may be defined within a wafer during manufacturing of the microelectronic devices. 
     In order to process the multiple layers, multiple mask sets are required. A stepper apparatus may be used to expose the multiple mask sets, layer by layer. However, often the reticle of the stepper apparatus is smaller than the size of the composite base die. Indeed, “large” generally refers to a base die that is bigger in area than the reticle. Thus, multiple passes of the wafer through the stepper apparatus are required and reticle stitching is needed. This is a time consuming and expensive process. Additionally, it can be possible to utilize multiple stepper apparatuses. However, stepper apparatuses are extremely expensive and thus, it is generally not practical to include multiple stepper apparatuses. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description is set forth below with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items. The systems depicted in the accompanying figures are not to scale and components within the figures may be depicted not to scale with each other. 
         FIG. 1  is a schematic diagram depicting an example illustrative layout of a wafer with composite base dies defined therein for use in microelectronic devices. 
         FIGS. 2A-2E  schematically illustrate example alternative layouts of composite base dies with respect to active regions and inactive regions. 
         FIG. 3  schematically illustrates a cross-sectional view of an example of a microelectronic device that includes a composite base die. 
         FIG. 4  illustrates a flow diagram of an example method for performing exposure operations on the wafer of  FIG. 1  utilizing both a stepper apparatus and an aligner apparatus. 
     
    
    
     DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Overview 
     This disclosure describes example techniques and arrangements for performing exposure operations on a wafer utilizing both a stepper apparatus and an aligner apparatus. The exposure operations are performed with respect to large composite base dies, e.g., interposers, defined within the wafer, where the interposers will become a part of microelectronic devices by coupling with active dies or microchips. The composite base dies may be coupled to the active dies via “native interconnects” or “native interfaces” utilizing direct bonding techniques. 
     “Direct-bonding” as used herein means direct-contact metal-to-metal bonding, oxide bonding, or fusion bonding between two metals, such as copper to copper (Cu—Cu) metallic bonding between two copper conductors in direct contact, with at least partial crystal lattice cohesion. Such direct-bonding may be provided by a hybrid bonding technique such as DBI®. (direct bond interconnect) technology to be described below, and other metal bonding techniques (Invensas Bonding Technologies, Inc., an Xperi Corporation company, San Jose, Calif.). “Core” and “core-side” as used herein mean at the location, signal, and/or level present at the functional logic of a particular die, as opposed to at the location, signal, and/or level of an added standard interface defined by a consortium. Thus, a signal is raw or “native” if it is operational at the core functional logic level of a particular die, without certain modifications, such as additional serialization, added electrostatic discharge (ESD) protection except as inherently provided by the particular circuit; has an unserialized data path, can be coupled across dies by a simple latch, flop, or wire, has no imposed input/output (I/O) protocols, and so forth. A native signal, however, can undergo level shifting, or voltage regulation for purposes of adaptation between dies of heterogeneous foundry origin, and still be a native signal, as used herein. “Active” as used herein (active base die) accords with the usual meaning of active in the semiconductor arts, as opposed to “passive.” Active components include transistor logic and amplifying components, such as the transistors. Passive components, on the other hand, do not introduce net energy into a circuit, and do not use an original source of power, except for power derived from other circuits connected to the passive circuit. 
     DBI bonding may be utilized for fine-pitch bonding in integrated circuit assembly, and can be applied to bond the die to the interconnect area. See for example, U.S. Pat. No. 7,485,968, which is incorporated by reference herein in its entirety. DBI bonding technology has also been demonstrated down to lower pitches in wafer-to-wafer approaches that do not have this individual die pitch limitation with the pick-and-place (P&amp;P) operation (Pick &amp; Place surface-mount technology machines). With DBI technology, under bump metalization (UBM), underfill, and micro-bumps are replaced with a DBI metalization layer. Bonding at die level is initiated at room temperature followed by a batch anneal at low temperature. ZiBond® direct bonding may also be used in some circumstances ((Ziptronix, Inc., an Xperi Corporation company, San Jose, Calif.). 
     In some configurations, the interconnects may be referred to as “direct-bonded native interconnects” that are metal-to-metal bonds formed directly between native conductors of a die and conductors of a second die, thereby forgoing the need for the complexity and overhead of standard interfaces. A native conductor of a die is an electrical conductor that has electrical access to the raw or native signal of the die, operational at the level of the core functional logic of the particular die, without significant modification of the signal for purposes of interfacing with other dies. The native interconnects for conducting such native signals from the core-side of a die can provide continuous circuits disposed through two or more cross-die boundaries without amplifying or modifying the native signals, except as desired to accommodate dies from different manufacturing processes. From a signal standpoint, the native signal of the IP core of one die is passed directly to other dies via the directly bonded native interconnects, with no modification of the native signal or negligible modification of the native signal, thereby forgoing standard interfacing and consortium-imposed input/output protocols. For example, the native interconnects described in U.S. Pat. No. 10,522,352, issued Dec. 31, 2019, entitled “Direct-Bonded Native Interconnects and Active Base Die”, which is incorporated by reference in its entirety, may be utilized according to some configurations. 
     The composite base dies on the wafer include active regions and inactive (passive) regions. The use of native interconnects to couple a composite base die to an active die in a microelectronic device requires a fine pitch in the active regions of the composite base dies. For example, the active regions may require a pitch in a range of one to 10 microns. In some configurations, the pitch may be less than one micron. In other configurations, the pitch may be in a range of 10 to 100 microns. The inactive regions generally only require a pitch of 130 microns and above. In some configurations, the pitch in the inactive regions may be 100 microns and above. 
     In configurations, the stepper apparatus may be utilized to expose (e.g., perform a lithographic operation on) active regions of composite base dies on the wafer. Thus, for a first layer of the base die, the stepper apparatus may expose an active region of a first large composite die defined in the wafer. The reticle of the stepper apparatus may then be moved or “overstep” to a second composite base die defined in the wafer. The stepper apparatus may then expose active regions in the first layer of the second base die. The process may repeat until all of the composite base die active regions of all of the composite base dies defined in the wafer have been exposed in the first layer. In configurations, if multiple active regions fit within the stepper apparatus&#39; reticle, then multiple active regions of a composite base die or composite base dies may be exposed and then the stepper apparatus may overstep and move the reticle to another set of active regions for exposure. In configurations, the aligner apparatus may be utilized to expose (e.g., perform a lithographic operation on) inactive regions of the composite base dies defined in the wafer. As is known, generally the wafer fits entirely within the aligner apparatus. Thus, all of the inactive regions of the composite base dies defined in the wafer may be exposed in the first layer with one single operation of the aligner. In some configurations, more than one aligner operation may be needed to expose all of the inactive regions of the composite base dies defined in the wafer. Use of both the stepper apparatus and the aligner apparatus results in no reticle stitching being required. Once the exposure operations have been performed in a layer, exposed areas may be etched. 
     Once the active regions and the inactive regions of the composite base dies defined in the wafer have been exposed and etched in the first layer, the process may be repeated for a second layer, a third layer, etc. Generally, other operations may be performed in addition to the exposure and etching operations of the various layers. For example, a resist may be applied to the layers of the wafer. In configurations, an antireflective coating may be applied to the entire wafer. The stepper apparatus may then be utilized to expose the active circuitry within the composite base dies as previously described. For example, the stepper apparatus may expose an active region within the first layer of a first composite base die and then the reticle may be moved, e.g., overstepped, to an active region of the second composite base die defined within the wafer. The stepper apparatus may then perform an exposure operation for the active region of the second composite base die. In configurations, the aligner apparatus may be used first to provide a pattern for alignment features for the stepper apparatus. 
     The wafer may then be processed using the aligner apparatus, e.g., the aligner apparatus may perform an exposure operation for the composite base dies defined in the wafer for the inactive regions, e.g., for the various features in the inactive regions including through silicon vias (TSVs). In configurations, TSVs in the active regions (via in the middle) may be exposed by the aligner apparatus. In some configurations, TSVs in the active regions (via in the middle) by the stepper apparatus in later exposure operations by the stepper apparatus. 
     After the aligner apparatus is used for exposure operations in the first layer, an etch/pattern operation may be performed by an appropriate apparatus. A cleaning operation may also be performed. In configurations, the first layer may be an implant layer and thus, implant operations may then be performed, e.g., a n-doping or a p-doping implantation operation may be performed. Masks may then be stripped and a further cleaning operation may then be performed. The process may then be repeated for a second layer, third layer, etc., depending on the number of implant layers. Once the implant layers are completed, then subsequent layers, e.g., metal layers, may be processed in a similar manner. In configurations, there may be additional operations performed not discussed herein. The operations discussed herein are merely examples and are not meant to be limiting. 
     Additionally, the order of the steps may be varied. For example, there could be negative or positive resists applied. Also, the stepper apparatus may expose active regions of a first layer and then the etching process may be performed for the exposed active regions in the first layer. The aligner apparatus may then expose inactive regions in the first layer and then the etching process may be performed before other operations are performed. 
     Example Embodiments 
       FIG. 1  is a schematic diagram  100  depicting an example illustrative layout of a wafer  102  with composite base dies  104   a - 104   h  (referred to herein singularly or collectively as  102 ) defined therein. In configurations, the wafer  102  may have more or fewer composite base dies  104  defined therein depending on the size of the composite base die  104 . The composite base dies  104  include active regions  1 A,  1 B,  1 C, and  1 D that are located on a corner of each composite base die  102 . Each composite die  104  also includes inactive regions  1 E,  1 F,  1 G, and  1 H.  FIGS. 2A-2E  schematically illustrate example alternative layouts of composite base dies  202   a ,  202   b ,  202   c ,  202   d , and  202   e  with respect to active regions  204  and inactive regions  206 , which correspond to active regions  1 A,  1 B,  1 C, and  1 D and inactive regions  1 E,  1 F,  1 G, and  1 H, respectively. As may be seen in  FIG. 2E , the composite base dies  104  illustrated in  FIG. 1  have a layout at least similar to the layout of composite base die  202   e . However, the composite base dies  104  may have a different layout, including, but not limited to, the example layouts illustrated in  FIGS. 2A-2D . 
     Referring back to  FIG. 1 , areas  106  of the wafer  102  that do not include any of the composite base dies  104  do not require exposure. Box  108   a  illustrates a reticle size of a reticle  108  of a stepper apparatus  110 . As can be seen from box  106 , the reticle  108  is larger than the sections  112  that include an active region and an inactive region, e.g., active region  1 A and inactive region  1 E, of the composite base dies  104 , but the composite base dies  104  are larger than the reticle  108 . Thus, the composite base dies  104  may be referred to as “large” composite base dies  104  since they are larger than the reticle  108 . 
     In configurations, the stepper apparatus  110  may be utilized to expose (e.g., perform a lithographic operation on) just the active regions  1 A,  1 B,  1 C, and  1 D of the composite base dies  104  using the reticle  108 . Thus, for example, the reticle  108  of the stepper apparatus  110  may be utilized to expose the active regions  1 A,  1 B,  1 C, and  1 D of the first composite base die  104   a . As can be seen from box  106 , the reticle  108  is sized such that the reticle  108  can expose all active regions  1 A,  1 B,  1 C, and  1 D of a composite base die  104   a  simultaneously. The stepper apparatus  110  may then overstep or move the reticle  108  to the next active regions  1 A,  1 B,  1 C, and  1 D of the second base die  104   b , thereby leaving a space between exposures. 
     An aligner apparatus  114  may then be utilized to expose (e.g., perform a lithographic operation on) the inactive regions  1 E,  1 F,  1 G, and  1 H of the composite base dies  104 . For example, portions of the inactive regions  1 E,  1 F,  1 G, and  1 H that may be utilized for metal fill for the backend of line (BEOL) layers of the composite base dies  104  may be exposed by the aligner apparatus  114 . Furthermore, TSVs in the inactive regions  1 E,  1 F,  1 G, and  1 H may be exposed utilizing the aligner apparatus  114 . Furthermore, power distribution routing may be exposed in the inactive regions  1 E,  1 F,  1 G, and  1 H utilizing the aligner apparatus  114 . Additionally, minimal signal or clock routing between composite base dies  104  outside the active regions  1 A,  1 B,  1 C, and  1 D may also be exposed utilizing the aligner apparatus  114 . The exposure operations performed by the stepper apparatus  110  and the aligner apparatus  114  occur layer by layer until all layers of the wafer  102  have been processed. 
     In configurations, there likely may be only one exposure per layer of the wafer  102  utilizing the aligner apparatus  114 . However, in configurations, there may be two exposures utilizing the aligner apparatus  114  where the aligner apparatus  114  exposes both the metal fills and TSVs in a layer. Likewise, there generally is only one exposure of active regions  1 A,  1 B,  1 C, and  1 D for each composite base die  104  per layer of the wafer  102  utilizing the stepper apparatus  110 . However, as previously noted, the stepper apparatus  110  exposes the active regions  1 A,  1 B,  1 C, and  1 D of the composite base dies  104  for each composite base die  104  defined within the wafer  102  individually, e.g., the reticle  108  is overstepped from one composite base die  104  to the next composite base die  104 . 
     In configurations, depending on the size of the reticle  108  and the layout of the composite base die  104 , multiple active regions  1 A,  1 B,  1 C, and  1 D of a composite base die  104  may be exposed simultaneously as is the case with the example of  FIG. 1 . For example, referring to back  FIG. 2A , as may be seen, the reticle size  208  is big enough to expose active regions  202   a  and  202   b  simultaneously. 
     Thus, in configurations, a limited region of each composite base die  104  may be exposed utilizing the stepper apparatus  110  while other regions within the backend of line (BEOL) and optionally the frontend of line (FEOL), e.g., implants, early metal layers, utilize the aligner apparatus  114  for exposure. In configurations, the implants and early metal layers, or the FEOL, may utilize the stepper apparatus  110  to achieve a fine pitch. 
       FIG. 3  schematically illustrates a cross-sectional view of an example of a microelectronic device  300 . The microelectronic device  300  includes active dies  302   a ,  302   b  located on a composite base die  304 , e.g., an interposer corresponding to a composite base die  104  of  FIG. 1 . Regions  306   a ,  306   b  are active regions corresponding to active regions  1 A,  1 B,  1 C, and  1 D of  FIG. 1 . Regions  308   a ,  308   b  are inactive regions corresponding to inactive regions  1 E,  1 F,  1 G, and  1 H of  FIG. 1 . In configurations, a bridging area  310  may be provided in the composite base die  304  between the active regions  306   a ,  306   b . The microelectronic device also includes TSVs  312  and bumps  314  to couple the microelectronic device  300  to, for example, a substrate, a circuit board, another microelectronic device, etc. (not illustrated). 
     As previously noted, the active regions  306   a ,  306   b  require a fine pitch to allow for native interfaces  316  between the active dies  302   a ,  302   b  and the composite base die  304 . In configurations, other types of interfaces between the active dies  302   a ,  302   b  and the composite base die  304  at the active regions  306   a ,  306   b  may be utilized. Such other types of interfaces require a high density pitch however. The inactive regions  308   a ,  308   b  as previously noted, generally only require a conventional (coarse) pitch to interface with passive regions  318   a ,  318   b  of the composite base die  304 . Such pitch is generally greater than 130 microns. In configurations, the pitch in the inactive regions  308   a ,  308   b  may be 100 microns to 130 microns. As previously noted, the fine pitch in the active regions  306   a ,  306   b  may be in a range of one micron to 10 microns. In some configurations, the fine pitch may be below one micron, while in other configurations, the fine pitch may be between 10 and 100 microns. Thus, interconnects in the active regions  306   a ,  306   b  on the composite base die  304  have a higher density, which is needed for native interfaces with the active dies  302   a ,  302   b  so that the composite base die  304  can handle driving the native interfaces. Thus, the stepper apparatus  110  is required to expose the various components in the layers of the active regions  306   a ,  306   b , as previously discussed, since the stepper apparatus  110  can achieve the higher density while the aligner apparatus  114  generally cannot. 
     As previously noted, the inactive regions  308   a ,  308   b , may have areas exposed in the various layers utilizing the aligner apparatus  114  (illustrated in  FIG. 1 ). Examples of areas exposed in the various layers of the inactive regions  308   a ,  308   b  include, for example, pass throughs, metal fills (which may be utilized to balance the interposer), an optional power mesh to provide a robust power supply for the resulting microelectronic device  300 , a minor routing to provide various signals, and “massive” passive components. 
     In configurations, the passive component comprises a capacitor. In other configurations, the passive component may comprise other devices, such as an inductor, a resistor, a voltage regulator, a filter, and/or a resonator. The passive component may be integrated into a layer of passive components (e.g., a massive number of passive devices) that is directly bonded to, for example, the actives dies  302   a ,  302   b . In configurations, for example, the layer of passive components may be disposed in a layer of the composite base die  304  and may directly connect with the active dies  302   a ,  302   b  via the inactive regions  308   a ,  308   b . The layer of passive components can thereby reduce the space occupied by passive components at the integrated device, at the package, and/or at the system board. Moreover, positioning the passive electronic component closer to active components of the active dies  302   a ,  302   b  may beneficially reduce overall inductance, which can improve the bandwidth and signal integrity of the semiconductor element, as compared with passive devices that are mounted to the package substrate or system board. In addition, the overall capacitance provided by the disclosed embodiments enables significantly higher capacitances (and reduced inductance) as compared with discrete passives mounted to a die. For example, the structures and techniques described in U.S. Patent Publication No. 2018/0190583A1, filed Feb. 7, 2017, entitled “Bonded Structures with Integrated Passive Component”, which is incorporated by reference in its entirety, may be utilized according to some configurations. 
     Referring back to  FIG. 1 , in configurations, the aligner apparatus  114  may be utilized first to provide (pattern) for alignment features for the stepper apparatus  110 . The stepper apparatus  110  may then be overstepped to expose only active regions  1 A,  1 B,  1 C, and  1 D or active circuitry as required. The stepper apparatus  110  is utilized layer by layer. The aligner apparatus  114  may be utilized for TSV locations in the active regions  1 A,  1 B,  1 C, and  1 D, e.g., “via in the middle.” The stepper apparatus  110  may be utilized in configurations for the TSV locations, e.g., via in the middle, for only the active regions  1 A,  1 B,  1 C, and  1 D. 
     In configurations, the stepper apparatus  110  may be utilized for all active regions  1 A,  1 B,  1 C, and  1 D of a layer of the wafer  102  and then the aligner apparatus  114  may be utilized for the inactive regions  1 E,  1 F,  1 G, and  1 H at the layer of the wafer  102 . In configurations, the process may be switched between the stepper apparatus  110  and the aligner apparatus  114  after several intermediate steps. For example, the stepper apparatus  110  may be utilized for exposure operations of active regions  1 A,  1 B,  1 C, and  1 D and then an etch operation may be performed by another component (not illustrated) on the exposed portions of the active regions  1 A,  1 B,  1 C, and  1 D. The aligner apparatus  114  may then be utilized for exposure operations of inactive regions  1 E,  1 F,  1 G, and  1 H and then an etch operation may be performed by another component (not illustrated) on the exposed portions of the inactive regions  1 E,  1 F,  1 G, and  1 H. 
     Thus, in some configurations, exposure steps may be performed and then another step may be performed or the steps may be alternated. For example, the stepper apparatus  110  may perform a lithography exposure operation on the active regions  1 A,  1 B,  1 C, and  1 D and then the aligner apparatus  114  may perform a lithography exposure operation on the inactive regions  1 E,  1 F,  1 G, and  1 H. An etch operation may be performed for all exposed areas in the active regions  1 A,  1 B,  1 C, and  1 D and the inactive regions  1 E,  1 F,  1 G, and  1 H. Alternatively, the stepper apparatus  110  may perform a lithography exposure operation on the active regions  1 A,  1 B,  1 C, and  1 D and then an etch operation may be performed on the exposed active regions  1 A,  1 B,  1 C, and  1 D. Then the aligner apparatus  114  may perform a lithography exposure operation on the inactive regions  1 E,  1 F,  1 G, and  1 H and then an etch operation may be performed on the exposed inactive regions  1 E,  1 F,  1 G, and  1 H. 
     Accordingly, as an example, the aligner apparatus  114  may be utilized first to pattern for alignment features for the stepper apparatus  110 . Once the active regions and the inactive regions of the composite base dies  104  defined in the wafer  102  have been exposed and etched in a first layer, the process may be repeated for a second layer, a third layer, etc., of the wafer  102 . 
     Generally, continuing with the example related to the first layer, other operations may be performed on the first layer in addition to the exposure and etching operations of the various layers of the wafer  102 . For example, a resist may first be applied to the first layer of the wafer  102 . In configurations, an antireflective coating may be applied to the entire wafer  102 . The stepper apparatus  110  may then be utilized to expose the active circuitry within the composite base dies  104 , as previously described. For example, the stepper apparatus  110  may expose active regions  1 A,  1 B,  1 C, and  1 D within the first layer of the first composite base die  104   a  and then the reticle  108  may be moved, e.g., overstepped, to active regions  1 A,  1 B,  1 C, and  1 D of the second composite base die  104   b  defined within the wafer  102 . The stepper apparatus  110  may then perform an exposure operation for the active regions  1 A,  1 B,  1 C, and  1 D of the second composite base die  104   b . This may be repeated for the active regions  1 A,  1 B,  1 C, and  1 D of the composite base dies  104   c - 104   h.    
     The wafer  102  may then be processed using the aligner apparatus  114 , e.g., the aligner apparatus  114  may perform an exposure operation for the composite base dies  104   a - 104   h  defined in the wafer  102  for the inactive regions  1 E,  1 F,  1 G, and  1 H, e.g., for the various features in the inactive regions  1 E,  1 F,  1 G, and  1 H including through silicon vias (TSVs). In configurations, TSVs in the active regions  1 A,  1 B,  1 C, and  1 D (via in the middle) may be exposed by the aligner apparatus  114 . In some configurations, TSVs in the active regions  1 A,  1 B,  1 C, and  1 D (via in the middle) by the stepper apparatus  110  in later exposure operations by the stepper apparatus  110 . In configurations, the TSVs may be continuous (one or more holes per net at a later step going through multiple dielectrics). In configurations, the TSVs may be disjointed with many offset vias at different diameters depending upon the layer of the wafer  102 . Any given layer of the composite base die  102  may include many TSVs. Jumpers between sections of the active regions  1 A,  1 B,  1 C, and  1 D that connect active dies  302   a ,  302   b  of  FIG. 3  of the microelectronic device  300  may be exposed by either the stepper apparatus  110  or the aligner apparatus  114  depending upon factors such as, for example, capability, cost, etc. 
     After the aligner apparatus  114  is used for exposure operations in the first layer, an etch/pattern operation may be performed by an appropriate apparatus. A cleaning operation may also be performed. In configurations, the first layer may be an implant layer and thus, implant operations may then be performed, e.g., a n-doping or a p-doping implantation operation may be performed. Masks may then be stripped and a further cleaning operation may then be performed. The entire process may then be repeated for a second layer, third layer, etc., depending on the number of implant layers. Once the implant layers are completed, then subsequent layers, e.g., metal layers, may be processed in a similar manner. In configurations, there may be additional operations performed not discussed herein. The operations discussed herein are merely examples and are not meant to be limiting. 
     Additionally, the order of the steps may be varied. For example, there could be negative or positive resists applied. Also, the stepper apparatus  110  may expose active regions of a first layer and then the etching process may be performed for the exposed active regions in the first layer. The aligner apparatus  114  may then expose inactive regions in the first layer and then the etching process may be performed before additional operations are performed. 
     In configurations, materials for the processes described herein may be dictated by the most demanding process, e.g., the stepper apparatus is the most likely apparatus to dictate the needed materials. For example, the stepper apparatus  110  may dictate the materials used in the other lithographic processes performed by the aligner apparatus  114 . Additionally, the light source of the stepper apparatus  110  needs to be compatible with the mask materials in all lithographic steps. Thus, in configurations, an antireflective coating may be placed on the wafer  102 . Generally, the antireflective coating is placed over the entire top surface of the wafer  102 . In configurations, in addition to or instead of the aligner apparatus  114 , a direct imaging apparatus may be utilized for features in the inactive regions. 
       FIG. 4  illustrates a flow diagram of an example method  400  for performing exposure operations on a wafer utilizing both a stepper apparatus and an aligner apparatus. The exposure operations are performed with respect to large composite base dies or interposers, e.g., composite base dies  104 , defined within the wafer, e.g., wafer  102 , where the interposers will become a part of microelectronic devices, e.g., microelectronic device  300 , by coupling with active dies or microchips, e.g., active dies  302   a ,  302   b . In configurations, the composite base dies may be coupled to the active dies via “native interconnects” utilizing direct bonding techniques. In the flow diagram, the operations of method  400  are shown as individual blocks. 
     At block  402 , a stepper apparatus may perform a first exposure operation on a first layer of the wafer with respect to a first active region of a first base die defined in the wafer. For example, the stepper apparatus  110  may perform a first exposure operation on a first layer of the wafer  102  with respect to the first active region, e.g., the active regions  1 A,  1 B,  1 C, and  1 D, of the first base die  104   a  defined in the wafer  102 . 
     At block  404 , a reticle of the stepper apparatus may be moved over a second active region of a second base die defined in the wafer. For example, the reticle  108  of the stepper apparatus  110  may be moved over the second active region, e.g., the active regions  1 A,  1 B,  1 C, and  1 D, of the second base die  104   b  defined in the wafer  102 . 
     At block  406 , the stepper apparatus may perform the first exposure operation on the first layer of the wafer with respect to the second active region of the second base die defined in the wafer. For example, the stepper apparatus  110  may perform the first exposure operation on the first layer of the wafer  102  with respect to the second active region, e.g., the active regions  1 A,  1 B,  1 C, and  1 D, of the second base die  104   b  defined in the wafer  102 . 
     At block  408 , an aligner apparatus may perform a second exposure operation on the first layer of the wafer with respect to a first inactive region of the first base die defined in the wafer and a second inactive region of the second base die defined in the wafer. For example, the aligner apparatus  114  may perform a second exposure operation on the first layer of the wafer  102  with respect to a first inactive region, e.g., the inactive regions  1 E,  1 F,  1 G, and  1 H, of the first base die  104   a  defined in the wafer  102  and a second inactive region, e.g., the inactive regions  1 E,  1 F,  1 G, and  1 H, of the second base die  104   b  defined in the wafer  102 . 
     While the invention is described with respect to the specific examples and configurations, it is to be understood that the scope of the invention is not limited to these specific examples and configurations. Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the examples and configurations chosen for purposes of disclosure and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. 
     Although the application describes configurations having specific structural features and/or methodological acts, it is to be understood that the claims are not necessarily limited to the specific features or acts described. Rather, the specific features and acts are merely illustrative of some embodiments that fall within the scope of the claims of the application.