Patent Publication Number: US-2023148124-A1

Title: Apparatus for the Temperature Control of a Substrate and Corresponding Production Method

Description:
PRIORITY CLAIM 
     This application is a continuation of pending application Ser. No. 16/477,976, filed on Jul. 15, 2019, which is a 35 U.S.C. 371 National Stage application of PCT/EP2018/050874, filed Jan. 15, 2018, which claims priority to German Application No. DE 10 2017 200 588.2 filed on Jan. 16, 2017. The entire contents of the above-mentioned PCT and European patent applications are incorporated herein by reference as part of the disclosure of this U.S. application. 
    
    
     BACKGROUND 
     The present invention relates to an apparatus for controlling the temperature of a substrate, in particular of a wafer substrate, and to a corresponding manufacturing method. 
     Although not limited thereto, the present invention and the problem on which it is based will be discussed with reference to integrated circuits at wafer level. 
     In the manufacturing flow during production of integrated circuits, wafer tests are performed on not yet diced wafers so that faulty integrated circuits can be detected early and removed. To this end, a wafer to be tested is placed into a wafer prober and brought to a desired test temperature using a temperature-controllable chuck located therein (apparatus for controlling the temperature of the wafer substrate). Once the wafer is at the desired test temperature, a contact needle arrangement located on a needle head is used to establish an electrical connection with the contact pads of the integrated circuit to be tested. The needle head having the contact needles is arranged on what is known as a probe card, which forms an interface between a testing system and the wafer via the contact needles of the needle head. 
     Wafer tests are typically performed in a temperature range between −40° C. and 200° C., in exceptional cases even at more extreme temperatures above or below zero. 
     Conventional apparatuses for controlling the temperature of a substrate, in particular of a wafer substrate, are provided with a closed cooling circuit, in which a cooling fluid circulates through channels in the substrate holder to a heat exchanger and back to the substrate holder. 
     EP 1 943 665 B1 discloses an apparatus for controlling the temperature of a substrate, in particular of a wafer, wherein the apparatus has a main body which is temperature-controlled by a first temperature-control device and a second temperature-control device, wherein the first temperature-control device is configured for controlling the temperature of the main body in a first temperature range between a first temperature and a second temperature, with the first temperature being lower than the second temperature, and is temperature-controlled using a first temperature-control fluid, and the second temperature-control device is configured for controlling the temperature of the main body in a second temperature range between a third temperature and a fourth temperature, with the third temperature being lower than the fourth temperature, and the second temperature-control device is temperature-controlled using a second temperature-control fluid, with the second temperature being lower than the fourth temperature and the first temperature-control fluid being different from the second temperature-control fluid. The main body has a substantially planar placement area having an attachment device, for attaching a substrate, which has a multiplicity of suction grooves, wherein one or more first temperature-control means channels for the first temperature-control fluid are provided inside the main body, which is located thereabove, and wherein the second temperature-control device for controlling the temperature of the main body comprises a temperature-control body that has, in its interior, one or more second temperature-control means channels for the second temperature-control fluid. 
     It has been found disadvantageous in this known apparatus for controlling the temperature of a substrate that it has a high volume due to the temperature-control devices that are located one above the other and that the lower temperature-control device is arranged far remote from the substrate. 
     SUMMARY OF THE DISCLOSURE 
     It is therefore an object of the present invention to provide an apparatus for controlling the temperature of a substrate which can be designed to be more compact, and a corresponding manufacturing method. 
     In order to achieve this object, the present invention provides an apparatus for controlling the temperature of a substrate and a corresponding manufacturing method. 
     The idea on which the present invention is based consists of embedding two different temperature-control devices in the main body in a space-saving and easily connectable manner. In particular, the respective distances of the temperature-control devices from the substrate can be set to be approximately equal in the apparatus for controlling the temperature of a substrate in accordance with the invention. 
     In accordance with a further preferred development, the main body has a plate-type bottom part and a plate-type top part, which are connected, in particular soldered or adhesively bonded, together in a connection region. This simplifies the manufacturing method. 
     In accordance with a further preferred embodiment, the first to fourth holes are provided in the bottom part, and the first plurality of separate annular channels and the second plurality of separate annular channels are provided in the top part. The tubes can thus be placed prior to the assembly of the top part and the bottom part. 
     In accordance with a further preferred embodiment, the first plurality of separate annular channels and the second plurality of separate annular channels are arranged concentrically with respect to a central axis of the main body, preferably circularly. 
     In accordance with a further preferred embodiment, the first plurality of separate annular channels and the second plurality of separate annular channels are arranged such that they encircle each other in alternation. In this way, it is possible to achieve a homogeneous temperature distribution by way of both temperature-control devices. 
     In accordance with a further preferred embodiment, the first plurality of separate annular channels and the second plurality of separate annular channels have respective different cross sections. It is possible in this way to take into consideration different viscosities of the two temperature-control fluids, e.g. gas/liquid. 
     In accordance with a further preferred embodiment, the first to fourth tubes are soldered or adhesively bonded to the main body. This ensures a high tightness of both circuits. 
     In accordance with a further preferred embodiment, the first to fourth tubes are made from stainless steel, copper or plastics material. 
     In accordance with a further preferred embodiment, the main body is made of copper or aluminium. This ensures a high thermal conductivity. For specific applications, highly thermally conductive ceramic materials would also be feasible. 
     In accordance with a further preferred embodiment, the first openings and the second openings are arranged in pairs such that they communicate with the respective annular channel at two sites that are arranged approximately equidistantly clockwise and anticlockwise along the respective annular channel. This ensures a homogeneous temperature distribution. 
     In accordance with a further preferred embodiment, the third openings and the fourth openings are arranged in pairs such that they communicate with the respective annular channel at two sites which are arranged approximately equidistantly clockwise and anticlockwise along the respective annular channel. This ensures homogeneous temperature distribution. 
     In accordance with a further preferred embodiment, the first and/or second and/or third and/or fourth tubes have a first, open end and a second, closed end, wherein the openings have a cross section that increases from the first, open end to the second, closed end. It is thus possible to compensate for the pressure drop occurring across the tubes. 
     In accordance with a further preferred embodiment, the first and/or second and/or third and/or fourth tubes have a plurality of openings per annular channel. It is thus possible to adjust the respective inflow and outflow directions, in particular to homogenize the temperature distributions. 
     In accordance with a further preferred embodiment, the plurality of openings are aligned in opposite directions of the associated annular channel. This results in a thermodynamically particularly effective counterflow inflow or outflow. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. 
         FIG.  1    shows a schematic planar cross-sectional view of an apparatus for controlling the temperature of a substrate in accordance with a first embodiment of the present invention; 
         FIG.  2    shows a partial perpendicular cross-sectional view of the apparatus for controlling the temperature of a substrate in accordance with the first embodiment of the present invention along the line X_X′ in  FIG.  1   ; 
         FIGS.  3   a ,  3   b    each show axial cross-sectional views of the first and second tubes of the apparatus for controlling the temperature of a substrate in accordance with the first embodiment of the present invention; 
         FIGS.  4   a ,  4   b    each show partial perpendicular cross-sectional views of the apparatus for controlling the temperature of a substrate in accordance with the first embodiment of the present invention in the region of the openings F 1  and L 3  for introducing the first or second temperature-control fluid; 
         FIGS.  4   d ,  4   d    each show partial perpendicular cross-sectional views of the apparatus for controlling the temperature of a substrate in accordance with the first embodiment of the present invention in the region of the openings F 1 ′ and L 3 ′ for removing the first or second temperature-control fluid; 
         FIG.  5    shows an axial cross-sectional view of the first tube of the apparatus for controlling the temperature of a substrate in accordance with a second embodiment of the present invention; and 
         FIG.  6    shows a partially perpendicular cross-sectional view of the apparatus for controlling the temperature of a substrate in accordance with a third embodiment of the present invention in the region of the openings F 11  and L 12  for introducing the first temperature-control fluid. 
     
    
    
     In the figures, identical reference symbols designate identical components or components having identical functions. 
     DETAILED DESCRIPTION 
       FIG.  1    is a schematic planar cross-sectional view of an apparatus for controlling the temperature of a substrate in accordance with a first embodiment of the present invention. 
     In  FIG.  1   , reference sign  1  designates a plate-type main body having a substrate placement area SF, which main body has a plate-type bottom part  1   a  and a plate-type top part  1   b,  which are connected to one another in a connection region V (cf.  FIG.  4   a   )- b )), for example by way of soldering or adhesive bonding. The substrate placement area SF can have grooves (not illustrated) which are connected to a negative pressure generation apparatus (not illustrated) to serve for stabilizing the placed substrate, for example a wafer substrate. 
     Provided inside the plate-type main body  1  is a first temperature-control device for controlling the temperature of the main body using a first temperature-control fluid, for example liquid, having a first plurality of separate encircling annular channels R 1 F-R 4 F inside the main body  1  for circulating the first temperature-control fluid, with R 1 F designating a first channel, R 2 F designating a second channel, R 3 F designating a third channel and R 4 F designating a fourth channel of the first plurality. 
     Furthermore provided inside the main body  1  is a second temperature-control device for controlling the temperature of the main body  1  using a second temperature-control fluid, for example gas, having a second plurality of separate annular channels R 1 L-R 5 L inside the main body  1  for circulating the second temperature-control fluid, with R 1 L designating a first channel, R 2 L designating a second channel, R 3 L designating a third channel, R 4 L designating a fourth channel and R 5 L designating a fifth channel of the second plurality. 
     The first temperature-control fluid is able to be supplied to the first plurality of annular channels R 1 F-R 4 F through a first tube K 1 F and to be removed therefrom through a second tube K 2 F. The first tube K 1 F and the second tube K 2 F are placed in a corresponding first hole B 1 F and a corresponding second hole B 2 F of the main body  1  (cf.  FIG.  2   ). The second temperature-control fluid is able to be supplied to the second plurality of annular channels R 1 L-R 5 L through a third tube K 1 L and to be removed therefrom through a fourth tube K 2 L. The third tube K 1 L and the fourth tube K 2 L are placed in a corresponding third hole B 1 L and fourth hole B 2 L in the main body  1  (cf.  FIG.  2   ). 
     The entrance Fi for the first temperature-control fluid is located at a first, open end E 1  of the first tube K 1 F, which furthermore has a second, closed end E 2 . The exit Fa for the first temperature-control fluid is located at a first, open end E 1 ′″ of the second tube K 2 F, which furthermore has a second, closed end E 2 ′″. 
     The entrance Li for the second temperature-control fluid is located at the first, open end E 1 ′ of the third tube K 1 L, which furthermore has a second, closed end E 2 ′. The exit La for the second temperature-control fluid is located at a first, open end E 1 ″ of the fourth tube K 2 L, which furthermore has a second, closed end E 2 ″. 
     The first to fourth tubes K 1 F, K 2 F, K 1 L, K 2 L are expediently additionally connected in a sealing manner to the main body  1 , for example by way of adhesive bonding or soldering. 
     The first to fourth tubes K 1 F, K 2 F, K 1 L, K 2 L expediently project laterally out of the main body  1  such that corresponding connections, e.g. flanges (not illustrated), can be attached thereto, which are connected to corresponding sources and sinks for the first and second temperature-control fluid, respectively. 
     The first to fourth holes B 1 F, B 2 F, B 1 L, B 2 L, which in the present example are blind holes, in each case communicate with the first plurality of separate annular channels R 1 F-R 4 F and the second plurality of separate annular channels R 1 L-R 5 L, i.e. they are open towards them. 
     The first tube K 1 F, which is placed in the first hole B 1 F of the main body  1 , has respective first openings F 1 -F 4  in the region of the first plurality of separate annular channels R 1 F-R 4 F for supplying the first temperature-control fluid, with F 1  designating a first opening, F 2  designating a second opening, F 3  designating a third opening and F 4  designating a fourth opening of the first openings F 1 -F 4 . 
     The second tube K 2 F, which is placed in the second hole B 2 F of the main body  1 , has respective second openings F 1 ′-F 4 ′ in the region of the first plurality of separate annular channels R 1 F-R 4 F for removing the first temperature-control fluid, with F 1 ′ designating a first opening, F 2 ′ designating a second opening, F 3 ′ designating a third opening and F 4 ′ designating a fourth opening of the second openings F 1 ′-F 4 ′. 
     The third tube K 1 L, which is placed in the third hole B 1 L of the main body  1 , has respective third openings L 1 -L 5  in the region of the second plurality of separate annular channels R 1 L-R 5 L for supplying the second temperature-control fluid, with L 1  designating a first opening, L 2  designating a second opening, L 3  designating a third opening, L 4  designating a fourth opening and L 5  designating a fifth opening of the third openings L 1 -L 5 . 
     The fourth tube K 2 L, which is placed in the fourth hole B 2 L of the main body  1 , has respective fourth openings L 1 ′-L 5 ′ in the region of the second plurality of separate annular channels R 1 L-R 5 L for removing the second temperature-control fluid, with L 1 ′ designating a first opening, L 2 ′ designating a second opening, L 3 ′ designating a third opening, L 4 ′ designating a fourth opening and L 5 ′ designating a fifth opening of the fourth openings L 1 ′-L 5 ′. 
     In the present example, the first plurality of separate annular channels R 1 F-R 4 F and the second plurality of separate annular channels R 1 L-R 5 L are arranged circularly concentrically with respect to a central axis M of the main body  1 . The first plurality of separate annular channels R 1 F-R 4 F and the second plurality of separate annular channels R 1 L-R 5 L are here arranged such that they encircle each other in alternation, with the result that a temperature distribution that is as homogeneous as possible is achievable. 
     The first to fourth tubes K 1 F, K 2 F, K 1 L, K 2 L are preferably made of stainless steel, copper or a plastics material, wherein the main body  1  is preferably made of copper or aluminium. 
     The first openings F 1 -F 4  and the second openings F 1 ′-F 4 ′ are arranged in pairs such that they communicate with the respective annular channel R 1 F-R 4 F at two sites which are arranged approximately equidistantly clockwise and anticlockwise along the respective annular channel R 1 F-R 4 F, i.e. they are approximately diametrically opposite in the present circular geometry. The third openings L 1 -L 5  and the fourth openings L 1 ′-L 5 ′ are arranged in pairs such that they communicate with the respective annular channel R 1 L-R 5 L at two sites which are arranged approximately equidistantly clockwise and anticlockwise along the respective annular channel R 1 L-R 5 L, i.e. they are approximately diametrically opposite in the present annular geometry. 
     This gives an inverse, substantially symmetric flow profile of the first and second temperature-control fluids. 
       FIG.  2    is a partial perpendicular cross-sectional view of the apparatus for controlling the temperature of a substrate in accordance with the first embodiment of the present invention along the line X_X′ in  FIG.  1   . 
     As can be seen in  FIG.  2   , in the present exemplary embodiment, the first to fourth holes B 1 F, B 2 F, B 1 L, B 2 L are provided in the bottom part  1   a,  and the first plurality of separate annular channels R 1 F-R 4 F and the second plurality of separate annular channels R 1 L-R 5 L are provided in the top part  1   b.  The first plurality of separate annular channels R 1 F-R 4 F are rectangular and have a first cross section Q 1 , and the second plurality of separate annular channels R 1 L-R 5 L are rectangular and have a second cross section Q 2 , with the second cross section Q 2  being smaller than the first cross section. This takes into consideration the fact that the first temperature-control fluid, in this case a liquid, and the second temperature-control fluid, in this case a gas, have different viscosities. 
     As can furthermore be seen from  FIG.  2   , a plate-type heating device HEI is furthermore provided on the bottom part  1   a  of the main body  1 , for example with an electric heating mechanism. 
       FIGS.  3   a ,  3   b    are in each case axial cross-sectional views of the first and second tubes of the apparatus for controlling the temperature of a substrate in accordance with the first embodiment of the present invention. 
       FIGS.  3   a ,  3   b    illustrate the first tube K 1 F and the third tube K 1 L in a state in which they are not placed in the main body  1 . As can be seen in particular, the cross sections of the first openings F 1 -F 4  are identical, as are the cross sections of the third openings L 1 -L 5 . However, the cross sections of the first openings F 1 -F 4  are larger than the cross sections of the third openings L 1 -L 5 . This, too, takes into consideration the different viscosities of the first and second temperature-control fluids and can be adapted as necessary. 
       FIGS.  4   a ,  4   b    are respective partial perpendicular cross-sectional views of the apparatus for controlling the temperature of a substrate in accordance with the first embodiment of the present invention in the region of the openings F 1  and L 3  for introducing the first and second temperature-control fluids. 
       FIG.  4   a   ) illustrates the intersection of the first tube K 1 F with the first annular channel R 1 F of the first plurality of annular channels R 1 F-R 4 F and the intersection of the third tube K 1 L with the first annular channel R 1 F of the first plurality of annular channels R 1 F-R 4 F. Since the first plurality of annular channels R 1 F-R 4 F is supplied by the first tube K 1 F, the latter is connected in the relevant region to the first annular channel R 1 F of the first plurality of annular channels R 1 F-R 4 F via the first opening F 1  of the first openings F 1 -F 4 , whereas the third tube K 1 L in this region passes through in a sealing fashion, with the result that the first and second temperature-control fluids cannot mix. This is correspondingly true for the remaining first openings F 2 -F 4 , which are connected in each case to the associated channel R 2 F, R 3 F, R 4 F of the first plurality of annular channels R 1 F-R 4 F, whereas the third tube K 1 L in these regions likewise passes through in a sealing fashion. 
     In corresponding fashion,  FIG.  4   b   ) shows the intersection of the first tube K 1 F with the third annular channel R 3 L of the second plurality of annular channels R 1 L-R 5 L, where the first tube passes through in a sealing fashion. The third tube K 1 L in this region is open by way of the third opening L 3  of the third openings L 1 -L 5 , so that the second temperature-control fluid can flow into the third annular channel R 3 L of the second plurality of annular channels R 1 L-R 5 L. This is correspondingly true for the remaining third openings L 2 -L 5 , which are each connected to the associated channel R 2 L, R 3 L, R 4 L, R 5 L of the second plurality of annual channels R 1 L-R 5 L, whereas the first tube K 1 F in these regions likewise passes through in a sealing fashion. 
       FIGS.  4   c ,  4   d    are in each case partial perpendicular cross-sectional views of the apparatus for controlling the temperature of a substrate in accordance with the first embodiment of the present invention in the region of the openings F 1 ′ and L 3 ′ for removing the first and second temperature-control fluid. 
     An analogous illustration is shown in  FIG.  4   c   ) for the removal of the first temperature-control fluid at the intersection of the fourth tube K 2 L and the second tube K 2 F with the first annular channel R 1 F of the first plurality of annular channels R 1 F-R 4 F, where the first temperature-control fluid can be removed through the first opening F 1 ′ and the fourth tube K 2 L passes through in a sealing fashion. This is correspondingly true for the remaining third openings F 2 -F 4 , which are each connected to the associated channel R 2 F, R 3 F, R 4 F of the first plurality of annular channels R 1 F-R 4 F, whereas the fourth tube K 2 L in these regions likewise passes through in a sealing fashion. 
     Finally,  FIG.  4   d   ) shows the intersection of the fourth tube K 2 L with the third annular channel of the second plurality of annular channels R 1 L-R 5 L and the corresponding intersection of the second tube K 2 F. The second temperature-control fluid is removed here through the third opening L 3 ′ into the fourth tube K 2 L, whereas the second tube passes through in a sealing fashion. 
     This is correspondingly true for the remaining third openings L 1 ′-L 5 ′, which are each connected to the associated channel R 1 L-R 4 L of the second plurality of annular channels R 1 L-R 4 L, whereas the second tube K 2 F in these regions likewise passes through in a sealing fashion. 
       FIG.  5    is an axial cross-sectional view of the first tube of the apparatus for controlling the temperature of a substrate in accordance with a second embodiment of the present invention. 
     The second embodiment illustrates in accordance with  FIG.  5    that the first openings F 1   a,  F 2   a,  F 3   a,  F 4   a  of the first tube K 1 F have different cross sections, wherein the cross sections of the openings F 1   a,  F 2   a,  F 3   a  F 4   a  increase from the first, open end E 1  to the second, open end E 2 . This takes into consideration the decreasing dynamic pressure of the first temperature-control fluid. 
       FIG.  6    is a partial perpendicular cross-sectional view of the apparatus for controlling the temperature of a substrate in accordance with a third embodiment of the present invention in the region of the openings F 11  and L 12  for introducing the first temperature-control fluid. 
     The third embodiment illustrates in accordance with  FIG.  6    a modification, in which the first tube K 1 F has a plurality of openings F 11 , F 12  per annular channel R 1 F-R 4 F of the first plurality of annular channels R 1 F-R 4 F. The outflow directions of the first temperature-control fluid can be influenced in this way and in particular hotspots, as they are known, above the tube in the top part  1   b  can be avoided. 
     In the present example, the openings F 11  and F 12  are aligned in opposite directions of the associated annular channel. 
     To produce the embodiments shown of the apparatus for controlling the temperature of a substrate, in particular of a wafer substrate, preferably first the holes B 1 F, B 2 F, B 1 L, B 2 L are made in the bottom part  1   a  of the main body, and subsequently the first to fourth tubes K 1 F, K 2 F, K 1 L, K 4 L are placed, aligned and sealed therein accordingly. 
     The first and second plurality of annular channels R 1 F-R 4 F and R 1 L-R 5 L are furthermore milled into the top part  1   b.  Subsequently, alignment and assembly and adhesive bonding or soldering are performed in the connection region V, which ultimately results in the above-described apparatus. 
     An alternative production method would be for the main body to be produced using a three-dimensional printing method, wherein the first to fourth tubes K 1 F, K 2 F, K 1 L, K 2 L are placed for example in an intermediate step after finishing the bottom part  1   a.    
     Although the present invention has been explained here with reference to preferred embodiments, it is not limited thereto, but is modifiable in various ways. 
     The first to fourth holes B 1 F, B 2 F, B 1 L, B 2 L in the present case are blind holes, although the invention is not limited thereto and instead, these holes can also be configured to pass through, and the tubes K 1 F, K 2 F, K 1 L, K 2 L can be either open on both sides with two connections in each case, or open on only one side, as above. 
     In particular, the geometric shape of the apparatus for controlling the temperature of a substrate is not limited to a round shape either, but can have any desired geometry. The stated materials are also only examples and can be widely varied. The geometric configuration of the channel system is also modifiable as desired.