Chuck system, method and use for holding a semiconductor wafer on a chuck

Abstract

A chuck system (1) is designed to hold a semiconductor wafer (100) on a chuck (20) and has a vapor chamber (10) with an evaporation surface (11) which is designed to absorb heat. The vapor chamber (10) furthermore has a condensation surface (12), which is designed to dissipate heat, and a fluid chamber (15), which is arranged between the evaporation surface (11) and the condensation surface (12) and in which a cooling fluid is arranged. The vapor chamber (10) is designed as a chuck attachment, in which, in an operating position placed on the chuck (20), the condensation surface (12) is in heat exchange with the chuck (20) and the evaporation surface (11) is designed to hold and regulate the temperature of the semiconductor wafer (100).

Description

[0001] Chuck system, method and use for holding a semiconductor wafer on a chuck

[0002] The invention relates to a chuck system, a method and a use for holding a semiconductor wafer on a chuck.

[0003] Test devices and methods are known from the prior art for testing semiconductor wafers in temperature ranges between -200°C and +400°C. A semiconductor wafer is placed on a test table that is cooled and / or heated to the desired test temperature. The semiconductor wafer is in direct heat exchange with the test table. Such test tables are also called wafer probers and / or chucks. A temperature control fluid is passed to and / or through the chuck to cool and / or heat it to the desired test temperature.

[0004] Document DE 10 2020 002 962 A1 describes an embodiment of a test device in which a temperature control fluid is first pre-tempered in an external temperature control device and then directed to a chuck of the test device. There, the temperature control fluid tempers the chuck to a test temperature at which a semiconductor wafer placed on the chuck is to be tested.

[0005] Modern semiconductor wafers feature increasingly smaller structures and tend to become ever more powerful. This generates more and more heat during operation, which must be cooled.

[0006] The invention is based on the objective of providing a means of efficiently temperature-controlling test tables for semiconductor wafers. A further objective of the invention may be to allow higher cooling capacities to act on the semiconductor wafer lying on the test table. This objective is achieved by the subject matter of the independent claims.

[0007] Preferred embodiments are the subject matter of the dependent claims.

[0008] One aspect concerns a chuck system for holding a semiconductor wafer on a chuck with a vapor chamber. The vapor chamber has an evaporation surface designed for heat absorption. Furthermore, the vapor chamber has a condensation surface designed for heat dissipation, and a fluid chamber located between the evaporation and condensation surfaces, containing a cooling fluid. The vapor chamber is designed as a chuck attachment, in which, when mounted on the chuck, the condensation surface is in heat exchange with the chuck, and the evaporation surface is designed for holding and temperature-controlling the semiconductor wafer.

[0009] The chuck can be referred to as a probe table and / or wafer prober and / or be configured accordingly. The chuck can be an integral part of the chuck system or an external component. Similarly, the semiconductor wafer can be an integral part of the chuck system or an external component.

[0010] The chuck can be temperature-controlled, meaning it can, for example, exchange heat with a temperature control fluid, which is either routed through the chuck or at least directed towards it. The temperature control fluid can be maintained in a temperature control device, which may include at least a heat exchanger and / or a cooling booster. The chuck can also interact with other temperature control devices, such as a heater.

[0011] Vapor chambers, also known as vapor chambers, are a well-known technology. They can be used, for example, to cool GPUs or CPUs and are installed in direct contact with them, allowing them to cool the GPU or CPU during normal operation. Hereinafter, the terms "vapor chamber" and "vapor chamber" will be used synonymously. Cooling via a vapor chamber is a heat dissipation technique that utilizes the evaporation and condensation of the cooling fluid to cool a semiconductor wafer, or more generally, an electronic component. In a chuck system, the vapor chamber is combined with the chuck to support the cooling process.

[0012] The vapor chamber can absorb and dissipate a large amount of heat, which is why it can improve and / or enhance the cooling of the semiconductor wafer.

[0013] The vapor chamber can have, for example, a flat housing lined with a wicking material and / or a wick structure. The vapor chamber includes at least the fluid chamber, which may be surrounded by a housing. The housing can be, for example, a metal housing, such as a copper housing. Since metal has high thermal conductivity, it is well-suited for heat exchange at the evaporation and / or condensation surface.

[0014] The cooling fluid, e.g., water, is located in the fluid chamber. The cooling fluid can be enclosed and / or vacuum-sealed within the fluid chamber. The pressure in the fluid chamber can differ from atmospheric pressure and be tailored to the intended application. For example, a reduced pressure in the vapor chamber can allow the cooling fluid to evaporate at temperatures below its normal boiling point.

[0015] The fluid chamber is formed between the evaporation surface and the condensation surface. It can be bounded on one side by the condensation surface and on the opposite side by the evaporation surface. The evaporation surface and / or the condensation surface can be formed as a housing surface of the fluid chamber housing. They are preferably formed on opposite sides of the fluid chamber. Both the evaporation surface and the condensation surface are in heat exchange with the cooling fluid enclosed in the fluid chamber via their respective inner surfaces.

[0016] The outer surface of the evaporation surface, i.e., the side of the evaporation surface facing away from the fluid chamber, is designed to hold the semiconductor wafer. Thus, in an operating position, the semiconductor wafer can, for example, be placed on the evaporation surface. The semiconductor wafer is therefore not placed directly on the chuck, as in the previously mentioned known test device, but rather on the vapor chamber located between the chuck and the semiconductor wafer—more precisely, on the evaporation surface of the vapor chamber. During test operation, the semiconductor wafer is thus in direct heat exchange with the evaporation surface of the vapor chamber.

[0017] During test operation of the semiconductor wafer, it heats up and transfers its heat to the evaporation surface. This causes the coolant in the fluid chamber to evaporate. This vapor, i.e., the gaseous coolant, circulates within the fluid chamber, for example, by convection. It can move relatively freely through the fluid chamber. If it encounters a cooler inner surface of the fluid chamber, it can condense and release the absorbed heat. This occurs particularly on the inner surface of the condensation area.

[0018] The outer surface of the condensation surface, i.e., the side of the condensation surface facing away from the fluid chamber, is in heat exchange with the chuck. The chuck may be at a specific temperature, particularly if it is cooled. Therefore, the vaporous cooling fluid condenses on the inner surface of the condensation surface.

[0019] The fluid chamber may be lined with a wicking material and / or contain a wicking material. This wicking material may also be called a wick.

[0020] The condensed, and therefore liquid, cooling fluid can be absorbed by the wick material and move along and / or through it, for example, due to capillary action. In this process, the cooling fluid can also flow back to the warmer side, i.e., to the inside of the evaporation surface. The cooling fluid can thus circulate. This process can continue as long as the semiconductor wafer is hot and / or requires cooling.

[0021] In this context, it may be of secondary importance and / or less relevant which surface of the vapor chamber is located at the top or bottom, since the cooling fluid circulates along the wick material, and gravitational forces may be negligible. Thus, the condensation surface can, for example, be located at the bottom and placed on the chuck. The evaporation surface can then be located at the top, allowing the semiconductor wafer under test to be placed onto the evaporation surface from above.

[0022] The housing, and therefore also the evaporation surface and / or the condensation surface, can be made of materials such as copper, aluminum, steel, and / or titanium. The wick material can be a wire mesh and / or sintered metal. Instead of water, methanol and / or ammonia and / or a mixture thereof can also be used as the cooling fluid.

[0023] The vapor chamber is designed as a chuck attachment. This means that the vapor chamber, and in particular its housing, is configured to be placed on the chuck in such a way that the condensation surface is in reliable and / or direct heat exchange with the chuck, especially with a temperature control surface of the chuck. The chuck attachment can be configured for a specific chuck type, for example, for a chuck from the L-series of ATT Advanced Temperature Test Systems GmbH, such as the L300T-LTR-XP chuck.

[0024] The chuck and / or the condensation surface can be configured so that, in the operating position, they are in reliable heat exchange with each other and / or do not slip relative to each other. For example, a target orientation of the condensation surface on the tempering surface of the chuck can be predetermined, e.g., by means of at least one coding element such as a projection and / or a coding lug that engages in a coding recess.

[0025] Similarly, the evaporation surface is designed to hold and temper the semiconductor wafer. In its operating position, the evaporation surface can be oriented, for example, horizontally, so that the semiconductor wafer can be securely positioned on it. The evaporation surface may have a recess for the semiconductor wafer to indicate a specific position for it.

[0026] To enable testing of differently shaped semiconductor wafers, the evaporation surface can also be designed for testing different semiconductor wafers. In this case, the evaporation surface can be essentially flat, allowing semiconductor wafers of varying sizes to be placed and tested on it. For this purpose, the evaporation surface can include at least one holding element for securing the semiconductor wafer, e.g., one of the holding elements described in more detail below.

[0027] The chuck system enables efficient cooling and / or temperature control of the semiconductor wafer. The cooling of, for example, the relatively small contact area of ​​the semiconductor wafer via the vapor chamber can be transferred to the relatively large temperature control surface of the chuck. This allows the small contact area of ​​the semiconductor wafer to be cooled by the large temperature control surface of the chuck, thus improving cooling efficiency.

[0028] The vapor chamber can dissipate heat from a spatially defined, small-area power element, i.e., the semiconductor wafer, onto a large-area chuck. This improves the distribution of the thermal load on the semiconductor wafer under test, which can be positioned arbitrarily on the evaporation surface. It is thus possible to cool the heat sources present at any point on the contact surface of the semiconductor wafer. One advantage of the vapor chamber is its ability to provide better thermal conductivity across the surface than direct contact with the chuck's tempering surface, which might be made of copper, for example. This allows even increasingly higher power densities in semiconductor development to be reliably cooled and thus tested. Conversely, the vapor chamber can also be used to heat the semiconductor wafer by heating the vapor chamber itself via the chuck.However, the focus may be on cooling the semiconductor wafer, since modern semiconductor wafers heat up considerably simply through their operation.

[0029] Using the chuck system, and in particular the chuck attachment, an existing chuck can be retrofitted. This allows a normally very expensive test fixture for semiconductor wafers to be retrofitted relatively cost-effectively for tempering modern semiconductor wafers, namely by means of the vapor chamber designed as a chuck attachment. The chuck system can be designed as a chuck retrofit system for at least one predetermined chuck type.

[0030] In one embodiment, the condensation surface is dimensioned such that it rests almost entirely on the chuck in the operating position. The condensation surface can, for example, be approximately flat, meaning it can have a nearly planar outer surface that rests fully on the tempering surface of the chuck. Alternatively, the condensation surface can also be at least partially stepped, with the steps of the condensation surface mirroring the steps of the tempering surface of the chuck. The full-surface contact allows for efficient cooling of the condensation surface.

[0031] In one embodiment, the outer surface of the condensation surface is approximately congruent with a temperature control surface of the chuck. The outer surface of the condensation surface corresponds to the outer surface of the condensation surface facing away from the fluid chamber. If the condensation surface is approximately congruent with the temperature control surface of the chuck, the entire temperature control surface of the chuck can be used to temper the cooling fluid in the fluid chamber and thus, for example, to cool the semiconductor wafer located on the evaporation side. This can improve the efficiency of the temperature control.

[0032] In one embodiment, the chuck system includes at least one fastening means for attaching the steam chamber to a tempering surface of the chuck. The fastening means can be designed, for example, to provide a positive-locking and / or frictional fastening of the steam chamber to the tempering surface of the chuck. For instance, the fastening means can include at least one screw, a clamp, a locking lug, a projection, and / or a recess. This enables reliable fastening of the steam chamber to the chuck, which is secured against, for example, vibrations and / or temperature-induced deformation. Furthermore, the fastening means can also be configured for suction fastening, for example, by means of a vacuum.

[0033] In one embodiment, the vapor chamber has at least one vacuum port through which a holding vacuum can be applied to the evaporation surface and / or the condensation surface. The vacuum port is designed and configured to be connected to a vacuum pump and / or a vacuum pump. The vacuum port can include a vacuum inlet and / or a vacuum outlet. Downstream of the vacuum port, at least one vacuum line can be provided, so that a vacuum applied at the vacuum port can be transmitted via these lines to the evaporation surface and / or the condensation surface. For example, a holding vacuum can be created between the condensation surface and the chuck and / or a holding pressure between the evaporation surface and the semiconductor wafer. This allows for and / or improves the fastening between the vapor chamber and the chuck and / or between the vapor chamber and the semiconductor wafer.

[0034] In a further embodiment, at least one holding recess is formed on the evaporation surface, which is connected to the vacuum connection, e.g., via at least one vacuum line, and in which a holding vacuum can be generated to retain the semiconductor wafer. The holding recess can include at least one holding groove. By pumping the air out of the holding recess via the vacuum connection, the holding vacuum for retaining the semiconductor wafer can be generated directly at the evaporation surface. In this way, the semiconductor wafer can be held in reliable heat exchange with the evaporation surface. In a further embodiment, at least one of the following holding vacuums can be generated at the holding recess:

[0035] - a ring retention vacuum; and / or

[0036] - a grid holding vacuum; and / or

[0037] - a plain holding vacuum; and / or

[0038] - a Bernoulli holding pressure; and / or

[0039] - a power holding vacuum.

[0040] These different holding pressures can be generated by differently shaped holding recesses, especially holding grooves. Depending on the application, one of the aforementioned modes for generating the holding vacuum can be selected. To create a ring holding vacuum, the holding recess can be designed as at least one ring in the evaporation surface, particularly as a plurality of concentric rings. To create a grid holding vacuum, the holding recess in the evaporation surface can be designed, for example, in a grid pattern, i.e., with several straight recesses intersecting approximately perpendicularly. To create a plain holding vacuum, the evaporation surface can be essentially flat and have a plurality of holes. In this case, the holding recess can thus be designed as a plurality of holes, which can be distributed more or less regularly across the evaporation surface.To create a Bernoulli holding vacuum, holding recesses of varying sizes can be formed in the evaporation surface to generate a Bernoulli vacuum during holding. To create a power holding vacuum, the holding recesses can be made somewhat wider to generate a stronger vacuum. A vacuum control can be provided for this purpose, allowing the respective holding vacuum to be adjusted. The vacuum control can include a software module and / or an actuating device. This allows the chuck system to be switched to one of the aforementioned operating modes.

[0041] In one embodiment, the chuck system comprises the chuck on which the vapor chamber with the condensation surface is arranged such that the condensation surface is in heat exchange with the chuck and, in particular, can be cooled by the chuck. In this embodiment, the chuck is thus a component of the chuck system. In this embodiment, not only the vapor chamber itself, but also the chuck can be configured so that these two components can be reliably attached to one another. Thus, not only the vapor chamber, but also (or alternatively) the chuck can have at least one fastening means for mounting and / or attaching the vapor chamber to the chuck. This can improve the reliability of this attachment.

[0042] In a further development of the embodiment, the chuck, in its operating position, regulates the temperature of the entire steam chamber. This is because the temperature control can be transferred to the entire steam chamber via the condensation surface and / or the wick material. This enables effective and / or efficient temperature control.

[0043] In general, the shape and / or size of the evaporation surface can roughly correspond to the shape and / or size of the condensation surface. These two surfaces can be located on opposite sides of the vapor chamber housing and be relatively close to each other. Their inner surfaces can be, for example, closer than about 1 cm apart, which can result in rapid condensation of the cooling fluid and thus a fast cooling effect.

[0044] In one embodiment, the vapor chamber is approximately cylindrical. The condensation surface is approximately disc-shaped, forming the base of the vapor chamber, and the evaporation surface is approximately disc-shaped, forming the top surface of the vapor chamber. The vapor chamber is thus designed as an approximately cylindrical chuck attachment, whereby the cylinder can be flat. It can have a height that is less than the cylinder radius, in particular at most about half the cylinder radius. For example, the cylinder height can be at most about 20% of the cylinder radius. This provides a flat vapor chamber whose disc-shaped base can mimic the temperature control surface of common (and usually disc-shaped) chucks, and which, due to its low height, can achieve efficient and reliable temperature control.

[0045] In a further development of the embodiment, a circular disk surface of the condensation surface is approximately congruent with an approximately circular disk-shaped cooling surface of the chuck. Here, the radius of the circular disk surface of the condensation surface can correspond approximately to the radius of the circular disk-shaped cooling surface of the chuck. Thus, these two circular disks can rest on each other almost completely in the mounted operating position, thereby enabling reliable heat exchange.

[0046] In a further development of the embodiment, the chuck has an insert recess in a tempering surface into which the steam chamber can be inserted such that the condensation surface is in heat exchange with the tempering surface. The insert recess can be surrounded by a rim within which the steam chamber can be securely placed onto the chuck. The insert recess and / or rim can reduce and / or prevent lateral displacement of the steam chamber relative to the tempering surface of the chuck. The steam chamber inserted into the recess can thus be securely fixed to the chuck.

[0047] In one embodiment, at least one temperature sensor is provided for measuring the temperature of the vapor chamber, which can be arranged, in particular, approximately in the center of the vapor chamber. This at least one temperature sensor enables temperature monitoring of the vapor chamber. If the temperature sensor is arranged approximately in the center, it can determine the central temperature of the vapor chamber. Alternatively, multiple temperature sensors can be provided, which can be arranged at different measuring points in the vapor chamber. This makes it possible to measure and / or monitor a temperature gradient along the vapor chamber. In this way, the operation and / or utilization of the vapor chamber can be determined and / or verified. This can reduce overloads and / or damage to the semiconductor wafer.

[0048] Another aspect concerns a test setup with a chuck system as described above. The test setup can include a temperature control unit in which a temperature control fluid is controlled. The temperature control fluid is directed to the chuck and heats it, for example, to a target temperature. The chuck, thus heated, then cools the semiconductor wafer resting on the evaporation surface via the vapor chamber. The temperature control fluid that cools the chuck differs from the cooling fluid contained in the fluid chamber of the vapor chamber. This difference is due, at least in part, to the fact that these fluids are located in separate compartments. The cooling fluid is contained exclusively within the fluid chamber, from which it cannot escape. The fluid chamber can therefore be designed to be vacuum-tight, ensuring that the cooling fluid remains permanently within it.

[0049] The temperature control fluid can be directed to and / or through the chuck and from there to, for example, the external temperature control device.

[0050] Furthermore, different types of fluids can be used. For example, pure air can be used as a temperature control fluid, and pure water as a cooling fluid.

[0051] The test apparatus can further include a test chamber in which the temperature-controlled chuck and the vapor chamber, designed as a chuck attachment, are arranged. A semiconductor wafer to be tested can be placed on the vapor chamber. During the test, the semiconductor wafer can be temperature-controlled and / or cooled via the chuck and the vapor chamber. The test chamber can be at least partially sealed and / or conditioned to ensure reproducible test conditions.

[0052] One aspect concerns a method for holding a semiconductor wafer on a chuck with a vapor chamber, comprising the steps of: providing a vapor chamber with an evaporation surface designed for heat absorption, with a condensation surface designed for heat release, and with a fluid chamber arranged between the evaporation surface and the condensation surface, in which a cooling fluid is arranged;

[0053] The vapor chamber is placed on the chuck so that the condensation surface is in heat exchange with the chuck, and the evaporation surface holds and tempers the semiconductor wafer.

[0054] The procedure can be carried out, for example, using a chuck system and / or a test device according to the aspects described above. Therefore, the explanations regarding the chuck system and / or the test device also apply to the procedure, and vice versa.

[0055] One aspect concerns the use of a vapor chamber to hold a semiconductor wafer on a chuck, wherein the vapor chamber comprises: an evaporation surface designed for heat absorption; a condensation surface designed for heat release; and a fluid chamber arranged between the evaporation surface and the condensation surface, in which a cooling fluid is arranged.

[0056] The vapor chamber is designed as a chuck attachment, which is placed onto the chuck in such a way that the condensation surface is in heat exchange with the chuck. The evaporation surface thus holds and tempers the semiconductor wafer.

[0057] The application can be carried out, for example, with a chuck system and / or a test fixture according to the aspects described above. Therefore, the explanations regarding the chuck system and / or the test fixture also apply to the application, and vice versa.

[0058] Within the scope of this invention, the terms “essentially” and / or “approximately” may be used to include a deviation of up to 5% from a numerical value following the term, a deviation of up to 5° from a direction following the term and / or from an angle following the term.

[0059] Terms such as above, below, over, under, lateral, etc. refer - unless otherwise specified - to the Earth's reference system in an operating position of the subject matter of the invention.

[0060] Preferred embodiments of the invention are described below by way of example. Here, identical or similar reference numerals can denote identical or similar features of the embodiments. Individual elements of the described embodiments are not limited to the respective embodiment. Rather, individual elements of the embodiments can be combined with one another to create new embodiments. This shows:

[0061] Fig. 1 shows a schematic representation of a chuck system according to an embodiment in which a steam chamber designed as a chuck attachment is placed on a chuck in an operating position;

[0062] Fig. 2 shows a schematic sectional view through a steam chamber according to one embodiment;

[0063] Fig. 3 shows a schematic sectional view through a section of a steam chamber according to one embodiment;

[0064] Fig. 4 shows a schematic sectional view along a horizontal

[0065] Section plane through a steam chamber according to one embodiment;

[0066] Fig. 5 shows a schematic functional diagram based on a vertical

[0067] Sectional view through a chuck system according to one embodiment;

[0068] Fig. 6 shows a schematic view of an evaporation surface of another embodiment of a vapor chamber;

[0069] Fig. 7 shows a schematic view of an evaporation surface of another

[0070] Design of a steam chamber;

[0071] Fig. 8 shows a schematic view of an evaporation surface of another

[0072] embodiment of a steam chamber; and

[0073] Fig. 9 shows a schematic view of an evaporation surface of another embodiment of a vapor chamber. Fig. 1 shows a schematic perspective view of a chuck system 1.

[0074] Chuck system 1 features a chuck 20 and a steam chamber 10.

[0075] Chuck 20 has a tempering surface 21 (hidden in the figure) onto which the steam chamber 10 is placed and / or rests. Chuck 20 can, for example, be cylindrical, with the tempering surface 21 forming a kind of cylinder lid on the top of Chuck 20.

[0076] Chuck 20 can have a temperature control port 22 through which a temperature control fluid can be fed into and / or out of the chuck 20. This allows the chuck 20 to be temperature controlled. The temperature control port 22 can, for example, be located on a lateral surface of the chuck 20. Inside, at least one temperature control line can penetrate the chuck 20, through which the temperature control fluid can be fed.

[0077] The steam chamber 10 can be attached to the tempering surface 21 of the chuck 20 by means of at least one fastening element (not shown in the figures). The fastening element can, for example, be designed as a lateral clamp and / or stop. The tempering surface 21 can, for example, be formed between lateral stops into which the steam chamber 10 can be inserted. The fastening element allows the steam chamber 10 to be reliably held in the operating position shown in Fig. 1.

[0078] The vapor chamber 10 has an evaporation surface 11 and an opposing condensation surface 12. The vapor chamber 10, with its condensation surface 12, rests almost entirely on the temperature control surface 21, which is why the condensation surface 12 is obscured in Fig. 1. The condensation surface 12 is in heat exchange with the temperature control surface 21 of the chuck 20. This allows the temperature control of the chuck 20 to be transferred to the condensation surface 12 of the vapor chamber 10. The vapor chamber 10 is designed as a chuck attachment, essentially as a vapor chamber add-on. The vapor chamber 10 can be shaped, for example, as a shallow cylinder, with the condensation surface 12 forming the cylinder base and the evaporation surface 11 the cylinder top. "Shallow cylinder" here means that the cylinder height is significantly smaller than the cylinder radius. For example, the cylinder height can be a maximum of approximately 20% of the cylinder radius.

[0079] The evaporation surface 11 is designed as a support surface for a semiconductor wafer (not shown in Fig. 1). The semiconductor wafer can simply be placed on the evaporation surface 11 and transfer its operating heat to it. The semiconductor wafer is in heat exchange with the evaporation surface 11.

[0080] The vapor chamber 10 has a vacuum connection 13, via which the vapor chamber 10 can be connected to a vacuum pump and / or negative pressure pump. A vacuum applied here is transmitted via vacuum lines to at least one retaining recess 14 formed in the evaporation surface 11. The retaining recess 14 can be designed as one or more retaining grooves, which can, for example, be arranged in a network along the outer surface of the evaporation surface 11 as shown in Fig. 1.

[0081] A holding recess 14 can create a holding vacuum on the evaporation surface 11, which can be configured to hold the semiconductor wafer. The semiconductor wafer is drawn onto the evaporation surface 11 by means of the holding recess 14, thereby improving and / or increasing the mechanical contact and thus the thermal contact.

[0082] The retaining grooves can be, for example, circular in the evaporation surface 11, e.g., in the form of several concentric circles of different sizes. The retaining grooves can be interconnected, e.g., via straight connecting grooves, such as radial retaining grooves extending from a central point to an edge of the evaporation surface 11. The retaining grooves can be distributed approximately over the entire evaporation surface 11. This makes it possible to apply a holding vacuum to essentially the entire outer surface of the evaporation surface 11. The semiconductor wafer can then be placed on the evaporation surface 11 at any desired position.

[0083] Figures 2 and 3 each show a schematic cross-sectional view through a steam chamber 10 of the chuck system 1. In each figure, a pie-shaped part of the steam chamber 10 has been cut along vertical sections, thus showing the interior of the steam chamber 10.

[0084] The vapor chamber 10 is at least partially hollow inside and has a hollow fluid chamber 15 inside. The vapor chamber 10 may also have a housing that includes, among other things, the evaporation surface 11 and the condensation surface 12.

[0085] The fluid chamber 15 is bounded from above by the evaporation surface 11 and from below by the condensation surface 12. Laterally, it may be bounded by a housing edge 18. The vacuum connection 13 shown in Fig. 1 may also be formed on this housing edge 18. The evaporation surface 11 and the condensation surface 12 may touch at the housing edge 18. They may be connected to each other there in an airtight and / or watertight manner.

[0086] Between the evaporation surface 11 and the condensation surface 12, spacer columns 17 are arranged inside the steam chamber 10. These columns can, for example, be made of the same housing material. The spacer columns 17 can each run approximately vertically, for example, approximately parallel to the cylinder axis of the steam chamber 10. The spacer columns 17 can be configured as spacers and / or connections between the evaporation surface 11 and the condensation surface 12.

[0087] The fluid chamber 15 can be designed as a connected cavity which is interrupted (e.g. only) by the spacer columns 17.

[0088] A cooling fluid (not shown in the figures), e.g., pure water, is enclosed in fluid chamber 15. The temperature at which the cooling fluid evaporates and condenses can be adjusted by changing the amount of cooling fluid and / or the pressure in fluid chamber 15. The cooling fluid is contained within fluid chamber 15 in a fluid-tight manner.

[0089] A wick material 16, which can also be called a wick, is formed on the inner surfaces of the fluid chamber 15. At least the inner surface of the evaporation surface 11 and the inner surface of the condensation surface 12 are covered with the wick material 16. In addition, the spacer columns 17 and / or the inner surfaces of the housing rim 18 can also be at least partially covered with the wick material 16. Preferably, the inner surface of the fluid chamber is almost completely lined with the wick material 16. The wick material 16 can be designed to receive and conduct the liquid cooling fluid.

[0090] Fig. 4 shows the vapor chamber 10 in a schematic sectional view along an approximately horizontal plane. It is shown that the fluid chamber 15 occupies essentially the entire interior and / or housing interior of the vapor chamber 10. The fluid chamber 15 is interrupted only by the spacer columns 17, which are covered with wicking material 16. The spacer columns 17 can be arranged more or less regularly within the fluid chamber 15. They can extend through the fluid chamber 15 from the condensation surface 12 to the evaporation surface 11, for example, along the chamber height, which is shown vertically in the figures.

[0091] Fig. 5 shows a schematic functional sketch of the operation of the steam chamber 10 based on a vertical sectional view through the chuck system 1.

[0092] The vapor chamber 10 is in its operating position with its condensation surface 12 placed on the temperature control surface 21 of the temperature-controlled chuck 20. A semiconductor wafer 100 is placed on the evaporation surface 11 of the vapor chamber 10 as a heat load and is held in place by a retaining vacuum applied via the groove-like retaining recesses 14. During operation of the semiconductor wafer 100, particularly during testing to verify its functionality in a test device, the wafer heats up. A contact surface of the semiconductor wafer 100 exchanges heat with the evaporation surface 11 of the vapor chamber 10, which heats up under the influence of the heat.

[0093] This leads to the evaporation of the cooling fluid located in the fluid chamber 15. The vapor circulates in and / or through the fluid chamber 15, encountering, among other things, the condensation surface 12. The entire surface of the condensation surface 12 is heated, and in particular cooled, by the chuck 20. Therefore, the vaporous cooling fluid condenses upon contact with the cooled condensation surface 12 and becomes liquid.

[0094] The liquid cooling fluid is guided back to the evaporation surface 11 along the wicking material 16, with which the fluid chamber is (e.g., completely) lined, e.g., via capillary action. The transport of the liquid cooling fluid can occur particularly along the spacer columns 17, which are also coated with the wicking material 16, and / or along the housing edge 18, which is also coated with the wicking material 16.

[0095] As shown in Fig. 5, the contact area of ​​the semiconductor wafer 100 on the evaporation surface 11 can be significantly smaller than the temperature control surface 21 of the chuck 20. The vapor chamber 10 thus allows the cooling capacity of the larger temperature control surface 21 to act on the smaller contact area of ​​the semiconductor wafer 100. Therefore, a concentrated thermal load can be distributed over the larger temperature control surface 21 of the chuck 20 by means of the vapor chamber 10. This increases the available cooling capacity and / or improves heat distribution, especially compared to directly placing the semiconductor wafer 100 on the chuck 20.

[0096] The orientation described above, insofar as it refers to terms such as "top," "bottom," "horizontal," and "vertical," etc., is to be understood as exemplary for the embodiment shown. In other embodiments, the vapor chamber 10, in particular its evaporation surface 11 and / or condensation surface 12, may be arranged differently, e.g., vertically or inverted. However, the orientation and arrangement of the embodiments shown in the figures may make it possible to modify partially known chuck designs as little as possible, but merely to supplement them with the chuck system 1.

[0097] Fig. 6 shows a schematic view of an evaporation surface 11 of another embodiment of a vapor chamber 10. Here, grid-like depressions are formed in the evaporation surface 11 as retaining recesses 14. The depressions are designed as approximately straight grooves that extend approximately the entire length of the evaporation surface 11 from a first end to a second, opposite end. One half of the grooves can be oriented approximately parallel to each other, and the second half approximately perpendicular to them, so that the grooves intersect approximately perpendicularly. The grooves can be spaced approximately equally apart.

[0098] With an evaporation surface 11 designed in this way, in which the holding recess 14 is approximately grid-like, a grid-based holding vacuum can be generated to hold the semiconductor wafer 100 (see Fig. 5). For this purpose, the holding recess 14 can be connected to the vacuum port 13, see Fig. 4. With such a grid-based holding vacuum, for example, a relatively uniformly distributed holding vacuum can be generated.

[0099] Fig. 7 shows a schematic view of an evaporation surface 11 of another embodiment of a vapor chamber 10. In this embodiment, the evaporation surface 11 has holes grouped in several clusters, forming retaining recesses 14. Several of the holes can each form an approximately concentric group of holes. Additionally, straight recesses can be formed between the groups of holes.

[0100] With such a designed evaporation surface 11, a powerful holding vacuum can be generated to hold the semiconductor wafer 100 (see Fig. 5). For this purpose, a powerful vacuum can be applied to the holes, i.e., a vacuum that is as strong as possible, which is generated by a particularly powerful vacuum pump and can thus create a strong and secure holding vacuum for the semiconductor wafer(s) 100.

[0101] Figures 8a and 8b show a further embodiment of a steam chamber 10. Figure 8a shows a schematic view of an evaporation surface 11 of the steam chamber 10 and Figure 8b a schematic sectional view of a section of the steam chamber 10.

[0102] In this process, the evaporation surface 11 is initially formed with several grooves 14a as a kind of retention recess, and several holes 14b between the grooves 14a as a further type of retention recess. The grooves 14a can, for example, be circular and / or approximately concentric to each other. The holes 14b can, for example, be arranged only between two concentric grooves 14a or between several of the grooves 14a.

[0103] With such a designed evaporation surface 11, a Bernoulli holding vacuum can be created to hold the semiconductor wafer 100 (see Fig. 5). The holes 14b can function as Bernoulli holes by allowing compressed air to escape from channels arranged at an angle to the holes 14b (see Fig. 8b). The resulting flow generates a vacuum on the evaporation surface 11, which is used to initially draw in the semiconductor wafer 100. Once the semiconductor wafer 100 is in place on the evaporation surface 11, the supply of compressed air through the angled channels and the holes 14b can be shut off, and the grooves 14a, which can be designed as vacuum grooves, can then secure the semiconductor wafer 100.

[0104] The Bernoulli effect can be used to increase the holding pressure, thus holding semiconductor wafers particularly securely.

[0105] Fig. 9 shows a schematic view of an evaporation surface 11 of another embodiment of a vapor chamber 10. In this embodiment, several holes are formed in the evaporation surface 11 as retaining recesses 14. The holes can be arranged, for example, approximately equidistantly and / or radially on the evaporation surface 11. They can extend substantially over the entire evaporation surface 11. Furthermore, the evaporation surface 11 can be approximately flat. The holes of the

[0106] A negative pressure can be formed in the holding recess 14.

[0107] With such a designed evaporation surface 11, a flat holding vacuum can be generated to hold the semiconductor wafer 100 (see Fig. 5). A relatively uniformly distributed holding vacuum can be generated with such a flat holding vacuum.

[0108] Reference symbol list

[0109] 1 Chuck system

[0110] 10 Steam chamber

[0111] 11 Evaporation surface

[0112] 12 Condensation surface

[0113] 13 Vacuum connection

[0114] 14 Retaining recess

[0115] 14a groove

[0116] 14b Hole

[0117] 15 Fluid chamber

[0118] 16 wicking material

[0119] 17 distance column

[0120] 18 Case edge

[0121] 20 Chuck

[0122] 21 Temperature control surface

[0123] 22 Temperature control connection

[0124] 100 semiconductor wafers

Claims

Patent claims 1. Chuck system (1 ) for holding a semiconductor wafer (100) on a chuck (20) with a vapor chamber (10), wherein the vapor chamber (10) has: - an evaporation surface (11) which is designed to absorb heat; - a condensation surface (12) designed for heat dissipation; and - a fluid chamber (15) arranged between the evaporation surface (11) and the condensation surface (12), in which a cooling fluid is arranged; wherein the vapor chamber (10) is designed as a chuck attachment, in which, in an operating position placed on the chuck (20), the condensation surface (12) is in heat exchange with the chuck (20), and the evaporation surface (11) is designed to hold and temper the semiconductor wafer (100).

2. Chuck system according to claim 1, wherein the condensation surface (12) is dimensioned such that it rests approximately over its entire surface on the chuck (20) in the operating position.

3. Chuck system according to claim 1 or 2, wherein an outer surface of the condensation surface (12) is formed approximately identically to a temperature control surface (21) of the chuck (20).

4. Chuck system according to one of the preceding claims, comprising at least one fastening means for attaching the steam chamber (10) to a tempering surface (21) of the chuck (20).

5. Chuck system according to one of the preceding claims, wherein the vapor chamber (10) has at least one vacuum port (13) through which an a holding negative pressure can be applied to the evaporation surface (11) and / or the condensation surface (12).

6. Chuck system according to claim 5, wherein at least one holding recess (14) is formed on the evaporation surface (11) which is connected to the vacuum connection (13) and in which a holding vacuum can be formed to hold the semiconductor wafer (100).

7. Chuck system according to claim 6, wherein at least one of the following retaining indentations can be formed on the retaining recess (14): - Ring retention vacuum; and / or - Grid holding pressure; and / or - Plain holding pressure; and / or - Bernoulli holding pressure; and / or - Power holding vacuum.

8. Chuck system according to one of the preceding claims, wherein the chuck system (1) comprises the chuck (20) on which the vapor chamber (10) with the condensation surface (12) is arranged such that the condensation surface (12) is in heat exchange with the chuck (20) and in particular can be cooled by the chuck (20).

9. Chuck system according to claim 8, wherein the chuck (20) in the operating position tempers the entire steam chamber (10).

10. Chuck system according to any of the preceding claims, wherein: - the steam chamber (10) is approximately cylindrical in shape; - the condensation surface (12) is approximately disk-shaped as the cylindrical base of the steam chamber (10); and - the evaporation surface (11 ) is designed approximately in the shape of a circular disk as the cylinder cover surface of the steam chamber (10).

11. Chuck system according to claim 10, wherein a circular disk surface of the condensation surface (12) is approximately congruent with an approximately a circular disc-shaped tempering surface (21) of the chuck (20) is formed.

12. Chuck system according to one of claims 8 to 11, wherein the chuck (20) has an insert recess in a tempering surface (21) into which the vapor chamber (10) can be inserted such that the condensation surface (12) is in heat exchange with the tempering surface (21).

13. Chuck system according to one of the preceding claims, comprising at least one temperature sensor for measuring the temperature of the steam chamber (10), which is arranged in particular approximately in the middle of the steam chamber (10).

14. Method for holding a semiconductor wafer (100) on a chuck (20) with a vapor chamber (10), comprising the steps: - Providing a vapor chamber (10) with an evaporation surface (11) designed for heat absorption, with a condensation surface (12) designed for heat release, and with a fluid chamber (15) arranged between the evaporation surface (11) and the condensation surface (12), in which a cooling fluid is arranged; - Placing the vapor chamber (10) on the chuck (20) so that the condensation surface (12) is in heat exchange with the chuck (20), and the evaporation surface (11) holds and tempers the semiconductor wafer (100).

15. Using a vapor chamber (10) to hold a semiconductor wafer (100) on a chuck (20), wherein the vapor chamber (10) has: - an evaporation surface (11) which is designed to absorb heat; - a condensation surface (12) designed for heat dissipation; and - a fluid chamber (15) arranged between the evaporation surface (11) and the condensation surface (12), in which a cooling fluid is arranged; wherein the vapor chamber (10) is designed as a chuck attachment which is placed on the chuck (20) in such a way that the condensation surface (12) is in heat exchange with the chuck (20), wherein the evaporation surface (11) holds and tempers the semiconductor wafer (100).

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