Device and method for thermally controlled zoned etching of wafer

Abstract

The present invention provides a device and method for thermally controlled partitioned etching of wafers, the device comprising an isolation mesh cylinder and a temperature-controlled etching system; the isolation mesh cylinder comprises a cylinder wall and an isolation mesh wall, the isolation mesh cylinder is used to be sleeved on the periphery of the wafer, the isolation mesh wall is used to separate the wafer surface into a plurality of mutually independent etching areas, and has a spacing with the wafer surface to form a non-contact air gap, based on the surface tension of the liquid so that the etching liquid will not enter another etching area adjacent to the etching area; the temperature-controlled etching system comprises a temperature controller, a heating driver, a heating unit and an etching liquid pipeline. The device for thermally controlled partitioned etching of wafers of the present invention has a simple structure and is easy to operate, and has the advantages of high efficiency and low cost for wafer surface treatment.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor integrated circuit design and manufacture, and in particular relates to a device and method for thermally controlled partitioned etching of a wafer. Background Art

[0002] The wafers produced by the thin film deposition or growth process of semiconductor manufacturing often have difficulty in achieving very uniform thickness or key performance indicators. Uniformity is the key to the consistency of performance and quality of back-end components. Existing methods mostly control the uniformity of wafer growth process to meet general manufacturing requirements. However, with the development of semiconductor technology and the increase in application costs and product consistency requirements, there is an urgent need for methods to further improve wafer uniformity.

[0003] At present, the technology to improve uniformity after wafer growth is mainly local thinning, but it is effective for larger areas, but it cannot perform fine differentiated etching in small areas, which will lead to problems such as widening of performance distribution and low yield. Especially in the field of sensing, the distribution differences of important indicators such as thickness and resistance of sensitive materials grown on semiconductor wafers will cause the sensitivity and accuracy of devices made from the same wafer at the back end to be highly discrete, resulting in uncontrollable product quality of the same wafer, and higher requirements must be placed on wafer uniformity.

[0004] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a device and method for thermally controlled zoned etching of wafers, so as to solve the problem of difficulty in controlling wafer uniformity in the prior art.

[0006] To achieve the above-mentioned purpose and other related purposes, the present invention provides a device for thermally controlled partitioned etching of wafers, the device comprising an isolation mesh cylinder and a temperature-controlled etching system; the isolation mesh cylinder comprises a cylinder wall and an isolation mesh wall, the isolation mesh cylinder is used to be sleeved on the periphery of the wafer, and is adsorbed and fixed together with the wafer by a vacuum adsorption table; the isolation mesh wall is fixed in the cylinder wall, and is used to divide the surface of the wafer into a plurality of independent etching areas, when the cylinder wall is fixed by the vacuum adsorption table, the isolation mesh wall extends above the surface of the wafer, and has a distance from the surface of the wafer to form a non-contact air gap, the non-contact air gap is configured so that when the etching liquid enters a certain etching area, based on the liquid Surface tension prevents the corrosive liquid from entering another corrosive area adjacent to the corrosive area; the temperature-controlled corrosion system includes a temperature controller, a heating driver, a heating unit and a corrosive liquid pipeline, wherein the heating unit includes a heater and a temperature detector, and each of the corrosive areas is provided with a corresponding heating unit; the temperature controller is used to transmit a power signal to the heating driver to control each heater for heating, each temperature detector is used to measure the real-time temperature of the corrosive area and feed it back to the temperature controller, and the power of the heater is closed-loop controlled by the temperature controller to achieve accurate temperature control; the corrosive liquid pipeline is used to add corrosive liquid to the corrosive area.

[0007] Optionally, the temperature detector is located at a position lower than the heater in the corrosion area.

[0008] Optionally, the cross-sectional area of ​​the heater is smaller than half of the area of ​​the corrosion region to ensure convection of the corrosion liquid in the corrosion region.

[0009] Optionally, the heater is a retractable and movable heater.

[0010] Optionally, the temperature-controlled corrosion system further includes a host computer for writing corrosion parameters of each corrosion area into a temperature controller, and the temperature controller transmits a corresponding power signal to a heating driver according to the corrosion parameters to control each heater to perform heating.

[0011] Optionally, the etching liquid pipelines include two or more groups, and the etching areas corresponding to any two etching liquid pipelines in the same group are not adjacent, so that there is no common adjacent wall between the etching areas of each group that are corroded simultaneously.

[0012] Optionally, the radial width of the barrel wall is greater than the radial width of the wafer, and when the barrel wall is sleeved around the periphery of the wafer, the distance between the barrel wall and the edge of the wafer is 30 microns to 500 microns.

[0013] Optionally, when the cylinder wall is fixed by the vacuum adsorption table, the distance between the isolation mesh wall and the wafer surface is 5 microns to 500 microns.

[0014] The present invention also provides a method for thermally controlled partitioned etching of wafers, comprising the steps of: 1) measuring the performance of the partitioned wafers to obtain the performance distribution of the wafers; 2) according to the performance distribution and the known corresponding relationship between the etching temperature and the etching amount of the wafer at a specific concentration and time, combined with the partition of the isolation net cylinder in the device for thermally controlled partitioned etching of wafers as described in any one of the above items, obtaining the etching temperature of each etching area, and grouping each etching area; 3) placing the wafer on a vacuum adsorption table, placing the isolation net cylinder directly above the wafer, and adsorbing and fixing the wafer and the isolation net cylinder; 4) inserting an etching liquid pipeline and placing a heater and a temperature detector in each etching area of ​​the first group to be etched, and turning on the heating function through a temperature controller and a heating driver; 5) injecting etching liquid into the etching area to be etched through the etching liquid pipeline, the height of the etching liquid is higher than the heater, and the timing is started. When the etching time is reached, the power is turned off, the isolation net cylinder is lifted, and the surface of the wafer is cleaned; and steps 3) to 5) are repeated to etch the etching areas of subsequent groups until the etching is completed.

[0015] Optionally, when each corrosion region is grouped, any two corrosion regions in the same group are not adjacent.

[0016] As described above, the device and method for thermally controlled zoned etching of wafers of the present invention have the following beneficial effects:

[0017] The present invention can realize grid-based fine partition etching on a wafer, and the shape and size of each grid etching area can be achieved in accordance with actual needs through the design of an isolation net, thereby satisfying more precise etching and achieving more stringent wafer uniformity requirements.

[0018] The isolation net wall of the present invention is spaced apart from the wafer surface to form a non-contact air gap. The non-contact air gap prevents the etching liquid from entering another adjacent etching area based on the surface tension of the liquid, thereby preventing the wafer surface from being scratched and the etching liquid from adjacent areas from being mixed and indistinguishable.

[0019] The device for thermally controlling partitioned etching of wafers of the present invention has a simple structure and is easy to operate, and has the advantages of high efficiency and low cost.

[0020] The etching method of the present invention has a relatively simple process, high efficiency and low cost, can reduce the variance of wafer device performance indicators by more than several times, and has broad application prospects in wafer surface treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application.

[0022] Figures 1 to 3 The structure diagram of the isolation mesh cylinder of the device for thermally controlling partitioned etching of wafers according to an embodiment of the present invention is shown, wherein: Figure 2 and Figure 3 The schematic diagrams of the top view of the rectangular grid partition and the triangular grid partition of the isolation net tube according to the embodiment of the present invention are shown respectively.

[0023] Figure 4 Shown is a schematic diagram of the structure of a device for thermally controlling partitioned etching of a wafer according to an embodiment of the present invention.

[0024] Figure 5 Shown is a schematic diagram of the etching sequence of rectangular grid partitions in a method for thermally controlled partitioned etching of a wafer according to an embodiment of the present invention.

[0025] Figure 6 Shown is a schematic diagram of the etching sequence of triangular mesh partitions in a method for thermally controlled partitioned etching of a wafer according to an embodiment of the present invention.

[0026] Explanation of component numbers: 101 cylinder wall, 102 isolation mesh wall, 103 vacuum adsorption table, 104 wafer, 105 corrosion area, 201 heater, 202 temperature detector, 203 corrosion liquid pipeline, 204 wire hose, 205 temperature controller, 206 heating driver, 207 host computer. DETAILED DESCRIPTION

[0027] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components.

[0029] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0030] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general scale, and the schematic view is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional space dimensions of length, width and depth should be included.

[0031] For ease of description, spatially relative terms such as "under," "below," "below," "below," "above," "on," etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

[0032] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0033] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0034] In the field of sensing, the distribution differences of important indicators such as the thickness and resistance of the growth of sensitive materials on semiconductor wafers will cause the sensitivity and precision of the devices produced by the same wafer at the back end to be highly discrete, resulting in uncontrollable product quality of the same wafer, and higher requirements must be placed on the uniformity of the wafer. Based on this, the present invention divides the surface of the wafer into fine grids, determines the required degree of corrosion of each grid area through precise measurement after the wafer grows, and then uses a temperature-controlled partitioned corrosion system to precisely control the etching of the partitioned wafers. The shape of the subdivided grid can be an equilateral triangle, a rectangle, a regular hexagon, or other shapes that can cover the entire wafer surface. In short, the present invention utilizes the difference in corrosion rates at different temperatures, and realizes precise corrosion of grid partitions through regional temperature control to achieve the purpose of homogenizing wafer performance.

[0035] like Figure 1~Figure 4 As shown, this embodiment provides a device for thermally controlled partitioned etching of wafers, and the device includes an isolation mesh cylinder and a temperature-controlled etching system.

[0036] like Figure 1~Figure 3As shown, the isolation mesh cylinder includes a cylinder wall 101 and an isolation mesh wall 102. The isolation mesh cylinder is used to be sleeved on the periphery of the wafer 104 and is adsorbed and fixed together with the wafer 104 by the vacuum adsorption platform 103; the isolation mesh wall 102 is fixed in the cylinder wall 101, and is used to separate the surface of the wafer 104 into a plurality of independent corrosion areas 105. When the cylinder wall 101 is fixed by the vacuum adsorption platform 103, the isolation mesh wall 102 extends above the surface of the wafer 104 and has a distance from the surface of the wafer 104 to form a non-contact air gap. The non-contact air gap is configured so that when the corrosive liquid enters a certain corrosion area 105, based on the surface tension of the liquid, the corrosive liquid will not enter another corrosion area 105 adjacent to the corrosion area 105.

[0037] In one embodiment, Figure 1 As shown, the radial width of the barrel wall 101 is greater than the radial width of the wafer 104. When the barrel wall 101 is sleeved around the periphery of the wafer 104, the distance D2 between the barrel wall 101 and the edge of the wafer 104 is 30 microns to 500 microns.

[0038] In one embodiment, Figure 1 As shown, when the cylinder wall 101 is fixed by the vacuum adsorption platform 103, the distance D1 between the isolation mesh wall 102 and the surface of the wafer 104 is 5 microns to 500 microns.

[0039] Figure 1 The figure shows the state of the isolation mesh cylinder installed when working. The isolation mesh cylinder and the wafer 104 are mounted on the same plane and fixed by the vacuum adsorption table 103. The lowest end of the isolation mesh wall 102 is 5 microns to 500 microns higher than the wafer 104, preferably 30 microns to 300 microns, forming a non-contact gap, which not only ensures that the wafer 104 will not be physically scratched, but also eliminates the situation where some parts are in direct contact and some cannot be in contact due to height differences caused by direct contact due to the uneven surface of the wafer 104. When the etching liquid enters a certain grid corrosion area 105, due to the surface tension of the liquid, the liquid will not enter the adjacent grid corrosion area 105. When there are etching liquids in adjacent grid corrosion areas 105, it is inevitable that the liquids will merge and form a mixture. Figure 2 The top view of the isolation net cylinder includes a vacuum-absorbable outer wall 101 and an internal isolation net wall 102. The mesh formed by the isolation net wall 102 can be designed into various shapes such as square, diamond, hexagon or ring according to the situation. The inner diameter of the isolation net cylinder is consistent with the size of the wafer 104 and is slightly larger by 5 microns to 500 microns, preferably 30 microns to 300 microns, so that the wafer 104 can be easily fitted when in use.

[0040] In order to etch accurately, the present invention ensures the independence of each etching area 105, so when in use, the etching liquid is not added to adjacent etching areas 105 at the same time. To this end, the present invention divides the surface of the wafer 104 into two groups (such as rectangular grids or triangular grids) to three groups (such as hexagonal grids) for etching. Each group simultaneously etches the etching areas 105 spaced apart to ensure that the etching liquid does not exist in the etching areas 105 with adjacent edges at the same time and cause confusion. For example, the square etching areas 105 separated by the isolation mesh tube can be marked in sequence (such as Figure 2 As shown in the figure), first fill the etching solution of the small areas 1, 3, 5, 7, ..., and perform the first group operation of local etching. After completion, take out the isolation net tube, clean the surface of the wafer 104 and then put it in, or do not take out the isolation net tube and directly perform the second group etching operation on the small areas 2, 4, 6 ... 14, etc. after local cleaning and drying.

[0041] In another embodiment, for Figure 3 The equilateral triangle corrosion area 105 can also be divided into two groups: 1, 2, 3...11... is the first group, and 01, 02, 03... is the second group. In this way, the independent parameterized corrosion of each corrosion area 105 can be ensured, and the corrosion liquid of adjacent areas will not be mixed and cannot be distinguished, so that the partitioned corrosion of the whole wafer 104 can be completed.

[0042] like Figure 4 As shown, the temperature-controlled corrosion system includes a temperature controller 205, a heating driver 206, a heating unit and a corrosion liquid pipeline 203, wherein the heating unit includes a heater 201 and a temperature detector 202, and each of the corrosion areas 105 is correspondingly provided with a heating unit; the temperature controller 205 is used to transmit a power signal to the heating driver 206 to control each heater 201 for heating, and each temperature detector is used to measure the real-time temperature of the corrosion area 105 and feed it back to the temperature controller 205, and the power of the heater 201 is closed-loop controlled by the temperature controller 205 to achieve accurate temperature control; the corrosion liquid pipeline 203 is used to add corrosion liquid to the corrosion area 105.

[0043] In one embodiment, the temperature detector 202 is located at a position lower than the heater 201 in the corrosion region 105. Preferably, the temperature detector 202 is disposed at a position closer to the surface of the wafer 104, such as 1 mm to 10 mm from the surface of the wafer 104, so as to provide more real-time and accurate feedback on the temperature of the surface of the wafer 104. The temperature detector 202 can also be located at a certain distance from the heater 201, such as 10 mm to 30 mm, so as to prevent the heat flow of the heater 201 from affecting the accuracy of the temperature detector 202.

[0044] In one embodiment, the cross-sectional area of ​​the heater 201 is smaller than half of the area of ​​the corrosion region 105 to ensure convection of the corrosion liquid in the corrosion region 105 .

[0045] In one embodiment, the heater 201 is a retractable and movable heater 201, which can be realized by an electric wire hose 204, so that when heating is not needed, it can be withdrawn from the isolation net tube without affecting the placement and removal of the isolation net tube.

[0046] In one embodiment, the temperature-controlled corrosion system further includes a host computer 207 for writing corrosion parameters of each corrosion area 105 into the temperature controller 205. The temperature controller 205 transmits a corresponding power signal to the heating driver 206 according to the corrosion parameters to control each heater 201 for heating.

[0047] In one embodiment, the etching liquid pipelines 203 include two or more groups, and the etching areas 105 corresponding to any two etching liquid pipelines 203 in the same group are not adjacent, so that there is no common adjacent wall between the etching areas 105 that are corroded simultaneously in each group.

[0048] Figure 4 It is shown as a temperature-controlled corrosion system. The three grid corrosion areas 105 listed are three of a group of rectangular grid corrosion areas 105. For the sake of clarity, other grid corrosion areas 105 are hidden. The heater 201 is placed at the bottom of the corresponding grid corrosion area 105 and turned on. The timing starts after the corrosion liquid is added to the corrosion liquid pipeline 203. The feedback control process can be controlled by classic PID control, and its control parameters are determined by the performance of each device. The optimal value is obtained through debugging tests to make the temperature rise rapid and stable. This process is a general temperature control debugging process and is not repeated in the content of the present invention.

[0049] This embodiment also provides a method for thermally controlling partition etching of a wafer 104, comprising the steps of:

[0050] 1) performing partition performance measurement on the wafer 104 to obtain performance distribution of the wafer 104;

[0051] 2) Based on the performance distribution and the known corresponding relationship between the etching temperature and the etching amount of the wafer 104 at a specific concentration and time, combined with the partitioning of the isolation mesh cylinder in the device for thermally controlled partitioned etching of the wafer 104 as described in any one of the above items, the etching temperature of each etching area 105 is obtained, and each etching area 105 is grouped;

[0052] 3) placing the wafer 104 on the vacuum adsorption table 103, placing the isolation mesh cylinder directly above the wafer 104, and adsorbing and fixing the wafer 104 and the isolation mesh cylinder;

[0053] 4) Insert the etching liquid pipeline 203 and the heater 201 and the temperature detector 202 into each etching area 105 of the first group that needs to be corroded, and turn on the heating function through the temperature controller 205 and the heating driver 206;

[0054] 5) Injecting etching liquid into the etching area 105 to be etched through the etching liquid pipeline 203, the height of the etching liquid is higher than the heater 201, and the timing is started. When the etching time is reached, the power is turned off, the isolation net cylinder is lifted, and the surface of the wafer 104 is cleaned;

[0055] Repeat step 3) to step 5) to erode the erosion area 105 of the subsequent group until the etching is completed.

[0056] In one embodiment, when the corrosion regions 105 are grouped, any two corrosion regions 105 in the same group are not adjacent.

[0057] In a specific example, the performance values ​​of each point of the wafer 104 (for example, more than 20 positions can be measured and evenly distributed on the surface of the wafer 104) can be measured to obtain a key performance distribution map. Then, the corrosion target value is given at the corresponding position of the grid corrosion area 105. Based on the parameter table of temperature and target value achieved under special corrosion conditions, the corrosion temperature corresponding to each grid corrosion area 105 is obtained by looking up the table, and input into the host computer 207 and written into the temperature controller 205. Figure 1 As shown, the isolation net cylinder of the present invention is placed on the wafer 104, so that the wafer 104 is inserted into the middle position of the isolation net cylinder and adsorbed on the vacuum adsorption table 103 together. Then, according to the principle that adjacent corrosion areas 105 are not corroded at the same time, two or three groups of regional corrosion are carried out separately, which can be carried out according to the following specific steps: 1) Place the corresponding heating function head in the first group of partition grids that need to be corroded in the temperature-controlled partition corrosion system, and turn on the heating and control and drive equipment. 2) Inject the etching liquid from the first group of pipelines into the first group of grids that need to be corroded at the same time. The amount of etching liquid must not exceed the heater 201, and then start the time immediately. 3) When the corrosion time is reached, turn off the power immediately, lift the isolation net, wash the surface of the wafer 104 with water and blow dry. Repeat steps 1-3, only replace the first group of grids with the second group, and if there is a third group, replace it. Take out the wafer 104 and clean the function head and pipeline to complete the corrosion.

[0058] In a specific implementation process, the resistance distribution is measured on the wafer 104, and the equal resistance map is as follows: Figure 5 As shown in the figure, the thinnest area corresponding to the maximum value of 170 ohms does not need to be corroded, and the areas between 165 ohms and 140 ohms need to be corroded. According to experience, the temperature required to corrode 140 ohms to 168 ohms in a given 9-minute corrosion time using a certain concentration of etching solution is shown in Table 1. Figure 5 For rectangular grid partitions, zone 1 168 ohms requires 22 degrees Celsius, zone 2 165 ohms requires 28 degrees Celsius, zone 3 160 ohms requires 37 degrees Celsius, zone 4 155 ohms requires 44 degrees Celsius, zone 5 150 ohms requires 49 degrees Celsius, zone 6 145 ohms requires 53 degrees Celsius, zone 7 143 ohms requires 54 degrees Celsius, zone 8 140 ohms requires 55 degrees Celsius... Divide into single and double groups for two-group step corrosion. The ambient temperature is 20 degrees Celsius.

[0059] Table 1

[0060]

[0061] like Figure 5 As shown, the zone-by-zone fixed temperature corrosion is performed according to the corresponding zones in the above table. The specific process is:

[0062] 1) The temperature of each grid is written into the temperature controller 205 through the host computer 207, and its output end corresponds to each grid corrosion area 105 one by one.

[0063] 2) The wafer 104 is placed on the vacuum adsorption table 103 of the device for thermally controlling partition etching of the wafer 104 .

[0064] 3) Place the isolation mesh cylinder directly on top and fix it by adsorption.

[0065] 4) Place the first group 1, 3, 5... grid corrosion areas 105 that need to be corroded in the temperature-controlled zoned corrosion system into corresponding heaters 201, correctly connect the output end of the temperature controller 205, and turn on the temperature controller 205 and the heating driver 206.

[0066] 5) Inject the etching liquid from the first set of pipelines into the first set of grid etching areas 105 that need to be corroded at the same time, add the etching liquid, and then immediately start the timing.

[0067] 6) When the 9-minute time is reached, the heating drive power is immediately turned off, the isolation net is lifted, and the surface of the wafer 104 is cleaned with water and blown dry.

[0068] 7) Repeat steps 3) to 6), replace the grid corrosion area 105 with 2, 4, 6, ..., and replace the corrosion liquid pipeline 203 with the second group.

[0069] 8) Take out the wafer 104 and clean the temperature detector 202, the heater 201 and the etching liquid pipeline 203 to complete the etching.

[0070] In a specific implementation process, the resistance distribution iso-resistance map measured on the wafer 104 is as follows: Figure 6As shown in the figure, the maximum value of 170 ohms corresponds to the thinnest part that does not need to be corroded, and the areas that need to be corroded are 165 ohms to 140 ohms. According to experience, the temperature required to corrode 140 ohms to 168 ohms in a given 7-minute corrosion time using a certain concentration of etching solution is shown in Table 2. Figure 6 For the grid-type partition, 145 ohms in zone 1 need 58 degrees Celsius, 143 ohms in zone 2 need 59 degrees Celsius, 143 ohms in zone 3 need 59 degrees Celsius, 143 ohms in zone 4 need 59 degrees Celsius, 140 ohms in zone 5 need 60 degrees Celsius, 140 ohms in zone 6 need 60 degrees Celsius, 140 ohms in zone 7 need 60 degrees Celsius, 145 ohms in zone 01 need 58 degrees Celsius..., divided into the first group 1, 2, 3...; and the second group 01, 02, 03... for two groups of step corrosion. The ambient temperature is 20 degrees Celsius.

[0071] like Figure 6 As shown, the corrosion area 105 is subjected to constant temperature corrosion according to the regular triangle partitions. The process is:

[0072] 1) The temperature of each grid is written into the temperature controller 205 through the host computer 207, and its output end corresponds to each grid corrosion area 105 one by one.

[0073] 2) The wafer 104 is placed on the vacuum adsorption table 103 of the device for thermally controlling partition etching of the wafer 104 .

[0074] 3) Place the isolation mesh cylinder directly on top and fix it by adsorption.

[0075] 4) Place the first group 1, 2, 3... grid corrosion areas 105 that need to be corroded in the temperature-controlled zoned corrosion system into corresponding heaters 201, correctly connect the output end of the temperature controller 205, and turn on the temperature controller 205 and the heating driver 206.

[0076] 5) Inject the etching liquid from the first set of pipelines into the first set of grid etching areas 105 that need to be corroded at the same time, add the etching liquid, and then immediately start the timing.

[0077] 6) When the 7-minute time is reached, the heating drive power is immediately turned off, the isolation net is lifted, and the surface of the wafer 104 is cleaned with water and blown dry.

[0078] 7) Repeat steps 3) to 6), replace the grid corrosion area 105 with the second group 01, 02, 03, ..., and replace the corrosion liquid pipeline 203 with the second group.

[0079] 8) Take out the wafer 104 and clean the temperature detector 202, the heater 201 and the etching liquid pipeline 203 to complete the etching.

[0080] Table 2

[0081]

[0082] As described above, the device and method for thermally controlling partitioned etching of the wafer 104 of the present invention have the following beneficial effects:

[0083] The present invention can realize grid-based fine partition etching on the wafer 104 , and the shape and size of each grid etching area 105 can be achieved in accordance with actual needs through the design of the isolation net, thereby satisfying more precise etching and achieving more stringent uniformity requirements of the wafer 104 .

[0084] The isolation mesh wall 102 of the present invention is spaced apart from the surface of the wafer 104 to form a non-contact air gap. The non-contact air gap prevents the etching liquid from entering another adjacent etching area 105 based on the surface tension of the liquid, thereby preventing the surface of the wafer 104 from being scratched and the etching liquid from the adjacent area from being mixed and indistinguishable.

[0085] The device for thermally controlling partitioned etching of the wafer 104 of the present invention has a simple structure and is easy to operate, and has the advantages of high efficiency and low cost.

[0086] The etching method of the present invention is relatively simple, efficient, and low-cost, and can reduce the variance of the performance index of the wafer 104 device by more than several times, and has a wide application prospect in the surface treatment of the wafer 104.

[0087] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0088] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A device for thermally controlling partitioned etching of wafers, characterized in that: The device includes an isolation mesh cylinder and a temperature control corrosion system; The isolation mesh cylinder comprises a cylinder wall and an isolation mesh wall, wherein the isolation mesh cylinder is used to be sleeved on the periphery of the wafer and is fixed together with the wafer by the vacuum adsorption platform; the isolation mesh wall is fixed inside the cylinder wall and is used to separate the surface of the wafer into a plurality of mutually independent corrosion areas, and when the cylinder wall is fixed by the vacuum adsorption platform, the isolation mesh wall extends above the surface of the wafer and has a distance from the surface of the wafer to form a non-contact air gap, and the non-contact air gap is configured such that when the etching liquid enters a certain corrosion area, the etching liquid will not enter another corrosion area adjacent to the corrosion area based on the surface tension of the liquid; The temperature-controlled corrosion system includes a temperature controller, a heating driver, a heating unit and a corrosion liquid pipeline, wherein the heating unit includes a heater and a temperature detector, and each corrosion area is correspondingly provided with a heating unit; the temperature controller is used to transmit a power signal to the heating driver to control each heater for heating, and each temperature detector is used to measure the real-time temperature of the corrosion area and feed it back to the temperature controller, and the power of the heater is closed-loop controlled by the temperature controller to achieve accurate temperature control; the corrosion liquid pipeline is used to add corrosion liquid to the corrosion area.

2. The device for thermally controlled zoned etching of wafer according to claim 1, characterized in that: The etching liquid pipelines include two or more groups, and the etching areas corresponding to any two etching liquid pipelines in the same group are not adjacent, so that there is no common adjacent wall between the etching areas of each group that are corroded simultaneously.

3. The device for thermally controlled zoned etching of wafer according to claim 1, characterized in that: The temperature probe is located at a position lower than the heater in the corrosion area.

4. The device for thermally controlled zoned etching of wafer according to claim 1, characterized in that: The cross-sectional area of ​​the heater is smaller than half of the area of ​​the corrosion area to ensure the convection of the corrosion liquid in the corrosion area.

5. The device for thermally controlled zoned etching of wafer according to claim 1, characterized in that: The heater is a retractable and movable heater.

6. The device for thermally controlled zoned etching of wafer according to claim 1, characterized in that: The temperature-controlled corrosion system also includes a host computer for writing corrosion parameters of each corrosion area into the temperature controller, and the temperature controller transmits a corresponding power signal to the heating driver according to the corrosion parameters to control each heater to heat.

7. The device for thermally controlled zoned etching of wafer according to claim 1, characterized in that: The radial width of the barrel wall is greater than the radial width of the wafer. When the barrel wall is sleeved on the periphery of the wafer, the distance between the barrel wall and the edge of the wafer is 30 microns to 500 microns.

8. The device for thermally controlled zoned etching of wafer according to claim 1, characterized in that: When the cylinder wall is fixed by the vacuum adsorption platform, the distance between the isolation mesh wall and the wafer surface is 5 microns to 500 microns.

9. A method for thermally controlled zoned etching of a wafer, characterized in that: Includes steps: 1) performing performance measurement on a partitioned wafer to obtain performance distribution of the wafer; 2) Based on the performance distribution and the known correspondence between the etching temperature and the etching amount of the wafer at a specific concentration and time, combined with the partitioning of the isolation mesh cylinder in the device for thermally controlled partitioned etching of the wafer as claimed in any one of claims 1 to 8, the etching temperature of each etching area is obtained, and each etching area is grouped; 3) placing the wafer on a vacuum adsorption table, placing the isolation mesh cylinder directly above the wafer, and adsorbing and fixing the wafer and the isolation mesh cylinder; 4) Insert the corrosion liquid pipeline, heater and temperature detector into each corrosion area of ​​the first group to be corroded, and start the heating function through the temperature controller and heating driver; 5) Injecting the etching liquid into the etching area to be etched through the etching liquid pipeline, the height of the etching liquid is higher than the heater, and the timing starts. When the etching time is reached, turn off the power, lift the isolation net cylinder and clean the wafer surface; Repeat steps 3) to 5) to erode the erosion areas of subsequent groups until the erosion is completed.

10. The method for thermally controlled zoned etching of a wafer according to claim 9, characterized in that: When the corrosion areas are grouped, any two corrosion areas in the same group are not adjacent.

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