Multi-wafer etching device

Abstract

The invention discloses a multi-wafer etching device, which comprises an etching cavity, a wafer rack, a first air inlet adjusting mechanism, a second air inlet adjusting mechanism, a first air outlet adjusting mechanism and a second air outlet adjusting mechanism, and is characterized in that the etching cavity is provided with an air inlet and an air outlet; the first air inlet adjusting mechanism, the second air inlet adjusting mechanism, the first air outlet adjusting mechanism and the second air outlet adjusting mechanism each comprise an adjusting plate and an adjuster, the adjuster can change the distance between the adjusting plates, and the air flowing path can be changed by adjusting the gap between the adjusting plates at the air inlet end and / or the air outlet end; therefore, the etching rates of the upper and lower wafers are balanced.

Description

Technical Field

[0001] The present application relates to the field of wafer etching technology, and in particular to a multi-wafer etching device. Background Art

[0002] In the semiconductor manufacturing industry, wafer etching is a key process that plays a decisive role in the performance and quality of chips. With the continuous development of semiconductor technology, in order to improve production efficiency and reduce production costs, multi-wafer etching processes are increasingly being adopted.

[0003] In the multi-wafer etching process, specific process vapors are usually used. These vapors contain active components that can react with the surface materials of the wafers to achieve etching of the wafers. However, the current multi-wafer etching process faces a more difficult problem - as the etching continues, the process vapors themselves have a certain weight, and under the action of gravity, these vapors will gradually settle downwards.

[0004] Since multiple wafers are stacked vertically in the etching equipment, the process vapor deposits downward, causing the vapor concentration around the lower wafer to be significantly higher than that of the upper wafer. Since the etching rate depends largely on the process vapor concentration around the wafer, the etching speed of the lower wafer is significantly faster than that of the upper wafer.

[0005] This difference in etching speed will lead to inconsistent etching depths between wafers, making it difficult to ensure the processing accuracy of the wafers, which in turn affects the performance and yield of the chip. Summary of the invention

[0006] The purpose of the present application is to overcome the deficiencies in the prior art and provide a multi-wafer etching device.

[0007] The present application provides a multi-wafer etching device, comprising: an etching chamber, for providing space for wafer etching, an air inlet is provided on one side of the etching chamber, and an air outlet is provided on the other side opposite thereto; a wafer rack, arranged in the etching chamber, for supporting the wafer, the wafer rack being a multi-layer bracket structure, capable of simultaneously carrying multiple wafers, and distributing the wafers at intervals in the vertical direction; a first air inlet regulating mechanism, arranged in the etching chamber, and located on the side of the first air homogenizing plate away from the air inlet, the first air inlet regulating mechanism comprising a plurality of first regulating plates and a first regulator, the plurality of first regulating plates being arranged at intervals in the vertical direction, the first regulator being used to adjust the gaps between the first regulating plates; a second air inlet regulating mechanism, also arranged in the etching chamber, and is located on the side of the first uniform air plate away from the air inlet. The second air inlet regulating mechanism includes a plurality of second regulating plates and a second regulator. The plurality of second regulating plates are arranged at intervals in the vertical direction. The second regulator is used to adjust the gap between the second regulating plates. The first regulating plate and the second regulating plate are arranged side by side in the vertical direction. The first outlet regulating mechanism is arranged in the etching chamber and is adjacent to the air outlet. The first outlet regulating mechanism includes a plurality of third regulating plates and a third regulator. The plurality of third regulating plates are arranged at intervals in the vertical direction. The third regulator is used to adjust the gap between the third regulating plates. The first regulating plate and the third regulating plate are arranged opposite to each other in the horizontal direction. The wafer rack is located between the first regulating plate and the third regulating plate. The second outlet regulating mechanism The regulating mechanism is also arranged in the etching chamber and adjacent to the gas outlet. The second gas outlet regulating mechanism includes a plurality of fourth regulating plates and a fourth regulator. The plurality of fourth regulating plates are arranged at intervals in the vertical direction. The fourth regulator is used to adjust the gap between the fourth regulating plates. The second regulating plate and the fourth regulating plate are arranged opposite to each other in the horizontal direction. The wafer rack is located between the second regulating plate and the fourth regulating plate. The third regulating plate and the fourth regulating plate are arranged side by side in the vertical direction. During the etching process, the process steam enters the first air cavity through the air inlet. The first air cavity helps the process steam to diffuse and then flow out uniformly from the first air hole. The outflowing process steam acts on the wafer on the wafer rack through the gap between the first regulating plate and the second regulating plate, thereby achieving Etching of wafers; process steam that does not participate in the reaction and byproducts generated by etching can be discharged through the gas outlet after passing through the gap between the third adjustment plate and the fourth adjustment plate; as etching proceeds, under the influence of gravity, the process steam will naturally settle downward, resulting in the etching rate of the wafer located at the lower layer being greater than the etching rate of the wafer located at the upper layer; the first air inlet adjustment mechanism is arranged above the second air inlet adjustment mechanism; the gap between the first adjustment plates is increased by the first regulator, and the gap between the second adjustment plates is reduced by the second regulator, and the process steam will preferentially choose the first gas outlet adjustment mechanism for flow, thereby increasing the process steam flow rate of the upper layer and promoting the etching of the wafer located at the upper layer;By increasing the gap between the third adjustment plates through the third regulator and reducing the gap between the fourth adjustment plates through the fourth regulator, the process steam will preferentially flow through the first outlet adjustment mechanism, thereby preventing the process steam from depositing downward, thereby optimizing the etching effect of the upper and lower wafers. ;

[0008] Further, the first regulator, the second regulator, the third regulator and / or the fourth regulator include: an adjusting shaft, which is rotatably arranged in the etching chamber and extends in the vertical direction, and a plurality of groups of symmetrically distributed guide grooves are provided on the adjusting shaft, and a group of guide grooves serving as the symmetry axis extends horizontally along the circumference of the adjusting shaft, and the other guide grooves extend obliquely compared to the symmetry axis, and the inclination angle gradually increases from both sides of the symmetry axis to form a continuous gradient layout; an adjusting driving member, used to drive the adjusting shaft to rotate; a plurality of adjusting sliders, an adjusting slider being slidably arranged in any guide groove, and any adjusting slider being connected to an adjusting plate; when it is necessary to change the distribution of the inlet or outlet airflow, the adjusting shaft is driven to rotate by the adjusting driving member, and the adjusting slider can slide along the guide groove, and affected by the layout of the guide groove, a set of adjusting plates connected to the adjusting slider can move in the vertical direction and change the spacing.

[0009] Furthermore, the multi-wafer etching device also includes: a first gas uniformizing plate, which is arranged in the etching chamber and adjacent to the air inlet, and a plurality of first air holes are opened on the first gas uniformizing plate, and the plurality of first air holes are evenly spaced along the vertical direction, and a first air cavity is formed between the first gas uniformizing plate and the air inlet, and the first air inlet regulating mechanism and the second air inlet regulating mechanism are located on the side of the first gas uniformizing plate away from the air inlet; a second gas uniformizing plate, which is arranged in the etching chamber and adjacent to the air outlet, and a plurality of second air holes are opened on the second gas uniformizing plate, and the plurality of second air holes are evenly spaced along the vertical direction, and a second air cavity is formed between the second gas uniformizing plate and the air outlet; the process steam that does not participate in the reaction and the by-products generated by etching will enter the second air cavity through the second air holes during the discharge process, and the second air cavity can buffer the fluctuation of the pumping speed, balance the pressure change, and play a role in maintaining the stability of the air pressure in the etching chamber.

[0010] Furthermore, the multi-wafer etching device also includes a temperature control mechanism, which is used to heat the etching chamber to maintain 60°C in the etching chamber; the temperature control mechanism includes a heating belt, and heating belts are attached to each outer wall of the etching chamber to fully heat the etching chamber and ensure that the temperature in the etching chamber is uniform everywhere.

[0011] Furthermore, the air inlet is connected to the process steam supply equipment through the air inlet pipe, and the air outlet is connected to the vacuum equipment through the air outlet pipe, and the air inlet pipe and / or the air outlet pipe are also affixed with a heating belt; and / or, the temperature control mechanism also includes a heating wire, the etching chamber includes an outer jacket and an inner liner, the outer jacket is made of metal material, and the inner liner is made of high temperature resistant and corrosion resistant material, and the heating wire is embedded between the outer jacket and the inner liner.

[0012] Furthermore, a lifting movable chamber is provided below the etching chamber, a lifting platform is provided in the lifting movable chamber, and the wafer rack is mounted on the lifting platform; after completing the etching of a batch of wafers, the lifting platform descends with the wafer rack, so that the wafer rack enters the lifting movable chamber, and a wafer inlet and outlet are provided on the lifting movable chamber, through which the wafers after etching can be unloaded and the wafers to be etched can be loaded; after the wafer rack is loaded with the wafer to be etched, the lifting platform ascends with the wafer rack, so that the wafer rack enters the etching chamber, so that the wafer can be etched.

[0013] Furthermore, the wafer rack is detachably arranged on the lifting platform; the wafer rack carrying the etched wafers is unloaded to realize fast unloading; and the wafer rack carrying the wafers to be etched is loaded to realize fast loading.

[0014] Furthermore, the lifting platform includes: a table portion, used to install a wafer rack, and can perform lifting and lowering movements under the drive of a lifting drive; a cover portion, arranged directly above the table portion; a connecting rod, used to connect the table portion and the cover portion; when a wafer rack is placed on the lifting platform, the wafer rack is located between the table portion and the cover portion; the multi-wafer etching device also includes an auxiliary gas supply pipeline, which is arranged in the lifting platform and connected to a process steam supply device; a first gas outlet is provided on the bottom surface of the cover portion facing the table portion, the first gas outlet is connected to the auxiliary gas supply pipeline, and / or a second gas outlet is provided on the side of the connecting rod facing the wafer rack, the second gas outlet is connected to the auxiliary gas supply pipeline; during the etching process, the process steam can be sprayed toward the wafer through the first gas outlet and / or the second gas outlet.

[0015] Furthermore, a connecting channel is provided between the etching chamber and the lifting movable chamber, and the lifting platform and the wafer rack can move between the etching chamber and the lifting movable chamber through the connecting channel; after the lifting platform carries the wafer rack into the etching chamber, the platform part can seal the connecting channel to prevent process steam from entering the lifting movable chamber; after the lifting platform carries the wafer rack into the lifting movable chamber, the cover part can seal the connecting channel to avoid interference between the processing operations in the lifting movable chamber and the etching chamber.

[0016] Furthermore, a cover is provided on the top of the wafer rack, and auxiliary air holes are provided on the side of the cover facing the wafer, and the auxiliary air holes are connected to the process steam supply equipment; the total etching time is 2N, and after the etching time exceeds N, at the air inlet end, the gap between the first adjustment plates is increased and the gap between the second adjustment plates is reduced, and at the air outlet end, the gap between the third adjustment plates is increased and the gap between the fourth adjustment plates is reduced. At the same time, the auxiliary air holes are enabled to allow the process steam to spray toward the wafer from top to bottom, which can effectively improve the etching difference between the upper and lower wafers.

[0017] The present application provides a multi-wafer etching device, including an etching chamber, a wafer rack, a first air inlet regulating mechanism, a second air inlet regulating mechanism, a first air outlet regulating mechanism, and a second air outlet regulating mechanism. The etching chamber is provided with an air inlet and an air outlet; the first air inlet regulating mechanism, the second air inlet regulating mechanism, the first air outlet regulating mechanism, and the second air outlet regulating mechanism all include regulating plates and regulators, and the regulators can change the spacing between the regulating plates. By adjusting the gap between the regulating plates at the air inlet end and / or the air outlet end, the gas flow path can be changed, thereby balancing the etching rates of the upper and lower wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a multi-wafer etching device provided in this application; Figure 2 for Figure 1 A magnified view of the structure in circle A; Figure 3 for Figure 1 A magnified view of the structure in circle B; Figure 4 for Figure 1 A schematic structural diagram of a first gas uniforming plate, a first gas inlet regulating mechanism and a second gas inlet regulating mechanism in a multi-wafer etching device shown; Figure 5 for Figure 4 The structural cross-sectional view after omitting the adjustment drive member; Figure 6 for Figure 4 A schematic diagram of the structure of the middle adjustment shaft; Figure 7 A schematic diagram of the structure of another multi-wafer etching device provided in this application. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0020] The present application provides a multi-wafer etching device, including: an etching chamber 100, used to provide space for wafer etching, an air inlet 101 is provided on one side of the etching chamber 100, and an air outlet 102 is provided on the other side opposite thereto; a wafer rack 200, arranged in the etching chamber 100, used to support the wafer, the wafer rack 200 is a multi-layer support structure, which can carry multiple wafers at the same time and make these wafers spaced apart in the vertical direction; a first air uniforming plate 310, arranged in the etching chamber 100 and adjacent to the air inlet 101, a plurality of first air holes are opened on the first air uniforming plate 310, and the plurality of first air holes are equally spaced apart in the vertical direction, and a first air cavity 103 is formed between the first air uniforming plate 310 and the air inlet 101.

[0021] In one specific embodiment, the process steam is VHF (hydrogen fluoride steam), supplemented with gaseous ethanol (EtOH) and nitrogen (N2). The process steam can enter the etching chamber 100 through the gas inlet 101. After contacting the wafer, the process steam will chemically react with silicon oxide (SiO2) on the surface of the wafer to generate volatile products.

[0022] The specific chemical reaction formula is: SiO2+4HF→SiF4↑+2H2O↑, wherein the gaseous SiF4 (silicon tetrafluoride) and H2O (water vapor) can be evacuated by the vacuum device through the gas outlet 102, thereby achieving accurate removal of silicon oxide.

[0023] Among them, ethanol, as a passivating agent, can inhibit lateral etching, making the etching mainly proceed in the direction perpendicular to the wafer surface, and can also improve the anisotropy of etching, which helps to form a precise etching pattern. In addition, gaseous ethanol can combine with water to form an azeotrope, which can reduce water vapor residue and avoid interference with the process, thereby ensuring the stability and accuracy of etching.

[0024] Nitrogen is used as a carrier gas to dilute the concentration of hydrogen fluoride. By adjusting the ratio of nitrogen to hydrogen fluoride, the reaction rate can be effectively controlled to avoid excessive or uneven etching caused by excessive reaction. When vaporizing ethanol, nitrogen can also lower the boiling point of ethanol by pressurizing it, making it easier to vaporize ethanol. At the same time, nitrogen pressurization also helps to hinder the liquefaction of gaseous ethanol to ensure that ethanol remains in a gaseous state during the etching process, thereby maintaining the gaseous stability of the process steam.

[0025] For details, please refer to Figure 1 In the illustrated embodiment, an air inlet 101 is provided on the right side of the etching chamber 100, and the air inlet 101 is connected to the process steam supply device through an air inlet pipeline. An air outlet 102 is provided on the left side of the etching chamber 100, and the air outlet 102 is connected to the vacuum pumping device through an air outlet pipeline.

[0026] Continue to refer to Figure 1The wafer rack 200 is installed inside the etching chamber 100. The wafer rack 200 includes at least two vertical rods. A plurality of support blocks are arranged on any vertical rod. The plurality of support blocks on the same vertical rod are evenly spaced along the vertical direction. The support blocks on different vertical rods and in the same plane can cooperate to support a wafer. With such an arrangement, the wafer rack 200 has a small shielding area for the wafer, so that the wafer can be fully exposed to the process steam.

[0027] On the wafer rack 200 , multiple wafers are stacked vertically with intervals between the wafers, so that each wafer can fully contact the process steam and the wafers do not interfere with each other, so as to meet the requirements of etching multiple wafers at the same time.

[0028] Combined with reference Figure 2 The first gas-distributing plate 310 is disposed in the etching chamber 100 and is located on the left side of the gas inlet 101. The first gas-distributing plate 310 is spaced apart from the right chamber wall where the gas inlet 101 is located, and the spaced apart form a sealed first gas cavity 103. The first gas-distributing plate 310 is provided with a plurality of first air holes equally spaced along the vertical direction, and the first air holes connect the first gas cavity 103 and the etching chamber 100.

[0029] The process steam introduced through the air inlet 101 will first enter the first air cavity 103. After diffusing in the first air cavity 103, the process steam can be evenly dispersed into each first air hole, and evenly flow to the etching area (i.e., the location of the wafer rack 200) through these first air holes. The existence of the first air cavity 103 can make the process steam evenly distributed before entering the etching area, thereby ensuring the uniformity of etching.

[0030] The multi-wafer etching device provided in the present application further includes: a first air intake regulating mechanism 410, which is arranged in the etching chamber 100 and is located on the side of the first air homogenizing plate 310 away from the air inlet 101, and the first air intake regulating mechanism 410 includes a plurality of first regulating plates 411 and a first regulator 412, the plurality of first regulating plates 411 are arranged at intervals in the vertical direction, and the first regulator 412 is used to adjust the gap between the first regulating plates 411; a second air intake regulating mechanism 420, which is also arranged in the etching chamber 100 The first air outlet regulating mechanism 430 is disposed in the etching chamber 100 and is adjacent to the air outlet 102. The second air inlet regulating mechanism 420 includes a plurality of second regulating plates 421 and a second regulator 422. The plurality of second regulating plates 421 are arranged at intervals in the vertical direction. The second regulator 422 is used to adjust the gap between the second regulating plates 421. The first regulating plate 411 and the second regulating plate 421 are arranged side by side in the vertical direction. The first air outlet regulating mechanism 430 is disposed in the etching chamber 100 and adjacent to the air outlet 102. The first gas outlet adjustment mechanism 430 includes a plurality of third adjustment plates 431 and a third adjuster 432. The plurality of third adjustment plates 431 are arranged at intervals in the vertical direction. The third adjuster 432 is used to adjust the gap between the third adjustment plates 431. The first adjustment plate 411 and the third adjustment plate 431 are arranged opposite to each other in the horizontal direction. The wafer rack 200 is located between the first adjustment plate 411 and the third adjustment plate 431. The second gas outlet adjustment mechanism 440 is also arranged in the etching chamber 100 and adjacent to the gas outlet 1 02, the second air outlet adjustment mechanism 440 includes a plurality of fourth adjustment plates 441 and a fourth adjuster 442, the plurality of fourth adjustment plates 441 are arranged at intervals along the vertical direction, the fourth adjuster 442 is used to adjust the gap between the fourth adjustment plates 441, the second adjustment plate 421 and the fourth adjustment plate 441 are arranged opposite to each other in the horizontal direction, the wafer rack 200 is located between the second adjustment plate 421 and the fourth adjustment plate 441, and the third adjustment plate 431 and the fourth adjustment plate 441 are arranged side by side in the vertical direction.

[0031] During the etching process, process steam enters the first air cavity 103 through the air inlet 101. The first air cavity 103 helps the process steam to diffuse and then flow out evenly from the first air hole; the outflowing process steam acts on the wafer on the wafer rack 200 through the gap between the first adjustment plate 411 and the second adjustment plate 421, thereby achieving etching of the wafer; the process steam that does not participate in the reaction and the by-products produced by etching can be discharged through the air outlet 102 after passing through the gap between the third adjustment plate 431 and the fourth adjustment plate 441.

[0032] As etching proceeds, under the influence of gravity, the process vapor will naturally deposit downward, causing the etching rate of the wafer at the lower layer to be greater than that of the wafer at the upper layer.

[0033] The first air inlet regulating mechanism 410 is arranged above the second air inlet regulating mechanism 420; the gap between the first regulating plates 411 is increased by the first regulator 412, and the gap between the second regulating plates 421 is reduced by the second regulator 422, and the process steam will preferentially choose the first air outlet regulating mechanism 430 to flow, thereby increasing the process steam flow of the upper layer and promoting the etching of the wafer located on the upper layer; the gap between the third regulating plates 431 is increased by the third regulator 432, and the gap between the fourth regulating plates 441 is reduced by the fourth regulator 442, and the process steam will preferentially choose the first air outlet regulating mechanism 430 to flow, thereby hindering the process steam from depositing downward, and then optimizing the etching effect of the upper and lower wafers.

[0034] For details, please refer to Figure 1 In the illustrated embodiment, the first air intake regulating mechanism 410 and the second air intake regulating mechanism 420 are arranged on the right side of the chamber, the first air uniforming plate 310 is located between the two groups of air intake regulating mechanisms and the right chamber wall where the air inlet 101 is located, and the wafer rack 200 is located on the left side of the two groups of air intake regulating mechanisms. The process steam uniformly flowing out through the first air hole can pass between the regulating plates of the first air intake regulating mechanism 410 and the second air intake regulating mechanism 420 and flow to the etching area.

[0035] Continue to refer to Figure 1 The first air intake regulating mechanism 410 includes a plurality of first regulating plates 411 spaced apart in the vertical direction, and the second air intake regulating mechanism 420 includes a plurality of second regulating plates 421 spaced apart in the vertical direction. The first regulating plates 411 and the second regulating plates 421 are arranged side by side in the vertical direction, and there is a gap between any two adjacent regulating plates for the process steam to flow. A grid-like wall is formed on the air intake path of the process steam through the first regulating plate 411 and the second regulating plate 421. When the process steam passes through, it will be dispersed into multiple airflows by the regulating plates to form a stable laminar flow or quasi-laminar flow, thereby reducing turbulence and eddy currents, which is beneficial to improving the uniformity of etching. Each stream of process steam can be blown to a layer of wafers, and the air receiving effect of the wafers can also be improved.

[0036] The first adjuster 412 and the second adjuster 422 can adopt any adjustment structure that is convenient for changing the gap between the plates, such as an electric cylinder cooperated with a connecting rod to cause the adjustment plate to move and change the spacing, or the adjuster cooperates with the adjustment plate to form a shutter form and change the spacing by flipping the adjustment plate.

[0037] The first regulator 412 can adjust the gap size between the first regulating plates 411 to control the flow rate of process steam to the upper area.

[0038] The second regulator 422 can adjust the gap size between the second regulating plates 421 to control the flow rate of the process steam to the lower area.

[0039] The first air intake regulating mechanism 410 and the second air intake regulating mechanism 420 work together to more accurately regulate the flow and distribution of process steam entering the etching area, ensuring that the process steam acts more effectively on the upper wafer and slows down the etching rate of the lower wafer.

[0040] Continue to refer to Figure 1 The first gas outlet regulating mechanism 430 and the second gas outlet regulating mechanism 440 are arranged on the left side of the chamber, near the gas outlet 102. The first gas outlet regulating mechanism 430 and the first gas inlet regulating mechanism 410 are arranged opposite to each other in the left-right direction, and the second gas outlet regulating mechanism 440 and the second gas inlet regulating mechanism 420 are also arranged opposite to each other in the left-right direction. The wafer rack 200 is located between the gas inlet regulating mechanism and the gas outlet regulating mechanism. The process steam that does not participate in the reaction and the by-products produced by etching will pass through the gas outlet regulating mechanism and flow out along the gas outlet 102 and the gas outlet pipeline under the influence of the pressure difference between the inside and outside of the chamber.

[0041] Continue to refer to Figure 1 The first gas outlet regulating mechanism 430 includes a plurality of third regulating plates 431 spaced apart in the vertical direction, and the second gas outlet regulating mechanism 440 includes a plurality of fourth regulating plates 441 spaced apart in the vertical direction. The third regulating plates 431 and the fourth regulating plates 441 are arranged side by side in the vertical direction, and there is a gap between any two adjacent regulating plates for the process steam and by-products to flow.

[0042] The third adjuster 432 and the fourth adjuster 442 may also adopt any adjustment structure that is convenient for changing the gap between the plates, and the details are not repeated here.

[0043] The third regulator 432 can adjust the gap size between the third regulating plates 431 to control the flow of process steam and by-products to the upper area.

[0044] The fourth regulator 442 can adjust the gap size between the fourth regulating plates 441 to control the flow of process steam and by-products to the lower area.

[0045] The first gas outlet regulating mechanism 430 and the second gas outlet regulating mechanism 440 work together to more accurately regulate the direction and flow rate of the process steam discharge, which is beneficial to preventing the process steam from depositing downward.

[0046] It should be added that when it is necessary to improve the problem of downward deposition of process steam, only the gap between the first adjustment plates 411 can be enlarged, or the gap between the second adjustment plates 421 can be reduced, so as to cause the process steam to flow mainly to the upper area; only the gap between the third adjustment plates 431 can be enlarged, or the gap between the fourth adjustment plates 441 can be reduced, so as to cause the process steam in the cavity to flow to the upper area and then be discharged, thereby hindering the sinking of the process steam to a certain extent; the gap between the first adjustment plates 411 can be enlarged, and the gap between the second adjustment plates 421 can be reduced, but the gap between the third adjustment plates 431 and the fourth adjustment plates 441 remains unchanged; the gap between the first adjustment plates 411 can be enlarged, and the gap between the second adjustment plates 421 can be reduced, while the gap between the third adjustment plates 431 can be enlarged, and the gap between the fourth adjustment plates 441 can be reduced. The synergistic effect of multiple groups of adjustment plates can further expand the gap between the gaps between the adjustment plates facing the upper area and the gaps between the adjustment plates facing the lower area, thereby better improving the steam concentration in the upper area, promoting the etching of the upper wafer while slowing down the etching of the lower wafer, thereby improving the etching uniformity of multiple wafers.

[0047] In a specific embodiment, the first adjustment plate 411 and the second adjustment plate 421 are evenly spaced, and the third adjustment plate 431 and the fourth adjustment plate 441 are also evenly spaced; process steam (composed of hydrogen fluoride vapor, gaseous ethanol and nitrogen) is introduced into the etching chamber 100 from the air inlet 101; the process steam first enters the first air cavity 103, diffuses in the first air cavity 103, and then flows out evenly through the first air hole; the outflowing process steam then enters the first air inlet adjustment mechanism 410 and the second air inlet adjustment mechanism 420, and flows to the etching area through the gap between the first adjustment plate 411 and the second adjustment plate 421; after the process steam contacts the silicon oxide material on the surface of the wafer, the hydrogen fluoride reacts chemically with the silicon oxide to generate gaseous silicon tetrafluoride and water vapor. Byproducts such as gaseous silicon tetrafluoride and water vapor generated by the reaction, as well as process steam that does not participate in the reaction, will flow to and pass through the gas outlet regulating mechanism, and finally be discharged through the gas outlet 102, thereby achieving precise removal of silicon oxide; after etching for a period of time, process steam has been deposited in the lower area; the gap between the first regulating plates 411 is increased by the first regulator 412, and the gap between the second regulating plates 421 is reduced by the second regulator 422, so that the process steam preferentially flows to the first air inlet regulating mechanism 410, thereby increasing the process steam flow of the upper layer and promoting the etching of the upper wafer; at the same time, the gap between the third regulating plates 431 is increased by the third regulator 432, and the gap between the fourth regulating plates 441 is reduced by the fourth regulator 442, so that the process steam flowing to the gas outlet 102 mainly flows to the first gas outlet regulating mechanism 430, thereby hindering the downward deposition of the process gas, slowing down the etching of the lower wafer, and optimizing the etching effect of the upper and lower wafers.

[0048] By adjusting the gap between the adjustment plates at the gas inlet and / or gas outlet, the gas flow path is changed, and the etching rates of the upper and lower wafers can be balanced.

[0049] In summary, the multi-wafer etching device provided in the present application cooperates with two groups of air inlet adjustment mechanisms through the first air uniformizing plate 310, so that the process steam can act evenly on multiple wafers, which helps to improve the etching effect of each wafer; by adjusting the gap between the adjustment plates at the air inlet end and / or the air outlet end, the flow direction and distribution of the gas can be changed, thereby balancing the etching rates of the upper and lower wafers, reducing product quality problems caused by differences in etching rates, and helping to improve the consistency and yield rate of a batch of products.

[0050] Optionally, during the etching process, the pressure in the chamber is maintained at 550 Torr.

[0051] The boiling point of ethanol at normal pressure is 78°C. At 550 Torr, the boiling point of ethanol will decrease (about 55~65°C) to maintain the gaseous state of ethanol and avoid the formation of droplets due to incomplete vaporization of ethanol, which will interfere with etching uniformity or induce side reactions (such as carbon-based pollutants).

[0052] In addition, under normal pressure or high pressure, vapor is more likely to be deposited downward under the action of gravity due to density differences. The design of medium and low pressure (550Torr) can reduce the difference in gas density, weaken the impact of gravity on vapor distribution, and reduce the difference in etching rates between the upper and lower wafers to a certain extent.

[0053] In one embodiment, in combination with reference Figure 1 , Figure 4 and Figure 5 The first gas homogenizing plate 310 is arranged in a square frame shape, the top of the first gas homogenizing plate 310 is connected to the inner top wall of the etching chamber 100, and the bottom of the first gas homogenizing plate 310 is connected to the inner bottom wall of the etching chamber 100. The first gas homogenizing plate 310 is open on one side away from the gas inlet 101, and a plurality of adjustment plates are arranged at intervals in the vertical direction on the open side of the first gas homogenizing plate 310.

[0054] In this embodiment, there is also a uniform air cavity between the first uniform air plate 310 and the adjustment plates of the first air intake adjustment mechanism 410 and the second air intake adjustment mechanism 420. When the number of adjustment plates is greater than the number of first air holes, the uniform air cavity helps the process steam to diffuse to the adjustment plates, and avoids the outflowing process steam from being mainly concentrated near the first air holes. In the present application, the spacing of the adjustment plates is variable. Assuming that, in the initial state, a set of adjustment plates are equally spaced along the vertical direction, and the spacing between the first air holes and the adjustment plates corresponds one to one, then, once the spacing of the adjustment plates is changed, the first air holes are no longer opposite to the spacing. When the first air holes are opposite to the spacing, the process steam flowing out through the first air holes can be quickly, naturally and accurately sprayed toward the wafer rack 200; when the first air holes are no longer opposite to the spacing, the first air holes will spray toward the adjustment plates, affecting the flow of the process steam. The uniform air cavity can play the role of storing gas and stabilizing pressure. Even if the first air holes are no longer opposite to the spacing, the process steam can be reliably guided to flow smoothly to the spacing.

[0055] In this way, the first air cavity 103, the first air homogenizing plate 310 and the air homogenizing cavity work together, so that the process steam can be evenly blown to the entire wafer rack 200 and act on each layer of wafers, which is beneficial to improving the uniformity of etching multiple wafers.

[0056] In this embodiment, the first gas uniformizing plate 310 also provides a location for installing the adjustment plate and the adjustment driver, thereby avoiding high-intensity processing of the etching chamber 100 and making the early installation and later maintenance of the equipment more convenient.

[0057] Optionally, the first air-distributing plate 310 is provided with multiple rows and columns of first air holes, and the multiple first air holes are distributed in an array. In this case, the first air holes are distributed not only vertically but also horizontally. The first air cavity 103 has more air outlet holes, and the process steam flowing through the first air-distributing plate 310 can flow out at more points, which is conducive to improving the comprehensiveness of air distribution.

[0058] Optionally, on the first air uniforming plate 310, the position of the first air hole in the vertical direction is adjustable; the first air hole can change position following the first adjustment plate 411 and / or the second adjustment plate 421 to ensure that each first air hole is always opposite to a gap formed by the two adjustment plates spaced apart.

[0059] In one embodiment, the first air uniforming plate 310 includes a fixed main plate and a movable sub-plate. The fixed main plate is sealed and connected to the etching chamber 100. The fixed main plate is provided with a long hole extending in the vertical direction. The movable sub-plate is slidably connected to the fixed main plate. The movable sub-plate is provided with a plurality of short holes distributed at intervals in the vertical direction. The long hole and the short hole are positioned relative to each other. The interval between two adjacent short holes can block the long hole, and the position where the long hole connects the short hole forms a first air hole. The movable sub-plate is moved in the vertical direction to change the position of the first air hole.

[0060] Furthermore, the movable sub-plate is composed of a plurality of small plates, each of which is provided with a first air hole, and an accordion cover is connected between two adjacent small plates to prevent process steam from flowing out from positions other than the short hole; any small plate is connected to a first adjustment plate 411 or a second adjustment plate 421. In this way, the small plate can follow the adjustment plate to perform lifting and lowering movements, and realize the position follow-up of the first air hole.

[0061] Optionally, the regulating plates at the air inlet end (the first regulating plate 411 and the second regulating plate 421 ) are always arranged symmetrically with the regulating plates at the air outlet end (the third regulating plate 431 and the fourth regulating plate 441 ).

[0062] For details, please refer to Figure 1 In the illustrated embodiment, the number and position of the adjustment plates on the left and right sides correspond one to one, and the intervals between the adjustment plates at the air inlet end and the gaps between the adjustment plates at the air outlet end also correspond one to one.

[0063] The symmetrical arrangement of the adjustment plates on both sides provides a symmetrical and regular channel for the flow of gas. At the air inlet end, the symmetrical layout of the adjustment plates ensures that when the process steam flows to the etching area, the resistance of each part is uniform and the airflow direction is stable, which is conducive to the formation of laminar flow or quasi-laminar flow. Stable laminar flow or quasi-laminar flow enables the process steam to act evenly on each wafer, which is conducive to improving the uniformity of etching. At the air outlet end, the symmetrical adjustment plates also ensure smooth and stable gas discharge, avoiding airflow turbulence caused by local pressure changes. The symmetrical design of the adjustment plates on both sides can reduce the turbulence and eddy current of the airflow in the etching chamber 100, so that the process steam can act more evenly on the wafer, and the exhaust gas can be discharged more stably, thereby maintaining the stability of the gas environment in the etching chamber 100 and ensuring the consistency of the etching reaction.

[0064] The symmetrical adjustment plate layout optimizes the flow and management of gas at both the inlet and outlet stages, so that the process steam can fully participate in the reaction. At the same time, the exhaust gas and by-products can be discharged in a timely and smooth manner to maintain a stable gas environment in the chamber.

[0065] The first regulator 412 , the second regulator 422 , the third regulator 432 and the fourth regulator 442 may adopt the same configuration, or may adopt different configurations according to actual needs of installation and regulation.

[0066] The first regulator 412 is taken as an example for description.

[0067] In one embodiment, the first regulator 412 adopts a structure of a connecting rod and a collar. Specifically, a connecting rod is provided in the etching chamber 100, and the connecting rod is extended in the vertical direction. A plurality of first adjustment plates 411 are inserted on the connecting rod, and the first adjustment plate 411 located at the bottom is fixed, and the other first adjustment plates 411 can slide along the connecting rod; a limiting collar is provided between any two adjacent first adjustment plates 411, and the limiting collar is slidably provided on the horizontal connecting rod; a traction rope is also provided between any two connected first adjustment plates 411, and the length of the traction rope when unfolded is greater than the length of the limiting collar.

[0068] When the gap between the first adjustment plates 411 needs to be reduced, the top first adjustment plate 411 is pushed to abut against the limiting ring, and then the next first adjustment plate 411 is pushed... and so on, until all the first adjustment plates 411 and the limiting rings abut against each other.

[0069] When the gap between the first adjustment plates 411 needs to be increased, the top first adjustment plate 411 is pulled to pull the traction rope, and then the next first adjustment plate 411 can be pulled up... and so on, until all the traction ropes are in a state of tensioning the first adjustment plates 411.

[0070] In another embodiment, an elastic member (such as a spring) and a stop block are provided between any two adjacent first adjustment plates 411. The first adjustment plate 411 at the bottom is fixedly arranged, and the other first adjustment plates 411 can move in the vertical direction.

[0071] When the gap between the first adjustment plates 411 needs to be reduced, pressure is applied to the top first adjustment plate 411 to make it move downward. After the elastic member is compressed, it can press down the next first adjustment plate 411 ... and so on, until all the first adjustment plates 411 and the limit blocks are against each other.

[0072] When the gap between the first adjustment plates 411 needs to be increased, the pressure on the top first adjustment plate 411 is released, and the elastic member is restored, so that all the first adjustment plates 411 can be reset.

[0073] This application does not limit the specific configuration of the regulator.

[0074] In a specific embodiment, the first regulator 412, the second regulator 422, the third regulator 432 and / or the fourth regulator 442 include: an adjusting shaft 412a, which is rotatably disposed in the etching chamber 100 and extends in the vertical direction, and a plurality of groups of symmetrically distributed guide grooves are provided on the adjusting shaft 412a, a group of guide grooves as the symmetry axis extends horizontally along the circumference of the adjusting shaft 412a, and the other guide grooves extend obliquely compared to the symmetry axis, and the inclination angle gradually increases from both sides of the symmetry axis to form a continuously gradient layout; an adjusting driving member 412b, which is used to drive the adjusting shaft 412a to rotate in the etching chamber 100 and extend in the vertical direction; The section shaft 412a rotates; there are multiple adjustment sliders 412c, and an adjustment slider 412c is slidably set in any guide groove, and any adjustment slider 412c is connected to an adjustment plate; when it is necessary to change the distribution of the intake or outlet air flow, the adjustment shaft 412a is driven to rotate by adjusting the driving member 412b, and the adjustment slider 412c can slide along the guide groove. Affected by the layout of the guide groove, a set of adjustment plates connected to the adjustment slider 412c can move in the vertical direction and change the spacing; the spacing between the adjustment plates is different when the adjustment shaft 412a rotates at different angles.

[0075] For details, please refer to Figures 1 to 6 In the illustrated embodiment, the first regulator 412, the second regulator 422, the third regulator 432 and the fourth regulator 442 all adopt an adjusting shaft 412a in combination with an adjusting driving member 412b; the first air intake regulating mechanism 410 and the second air intake regulating mechanism 420 are symmetrically arranged in the vertical direction, and the first air outlet regulating mechanism 430 and the second air outlet regulating mechanism 440 are symmetrically arranged in the vertical direction.

[0076] The first regulator 412 is taken as an example for description.

[0077] Figure 1 In the illustrated embodiment, the adjusting shaft 412a of the first adjuster 412 extends in the vertical direction, and the upper end passes through the etching chamber 100 and is connected to the adjusting driving member 412b disposed outside. The adjusting driving member 412b can be any driving structure that can conveniently drive the adjusting shaft 412a to rotate, such as a rotary cylinder or a motor. The adjusting driving member 412b is disposed outside the chamber to facilitate installation, maintenance, and the like.

[0078] Continue to refer to Figure 6, the surface of the adjustment shaft 412a is provided with multiple groups of guide grooves, and the multiple groups of guide grooves are distributed in a symmetrical fan shape. The group of guide grooves located in the middle can be regarded as the symmetry axis in the fan shape, and the group of guide grooves extends horizontally along the circumference of the adjustment shaft 412a; the remaining guide grooves extend obliquely compared to the symmetry axis, and the farther away from the symmetry axis, the greater the inclination angle of the guide grooves (for example, the inclination angle of the group of guide grooves as the symmetry axis is 0°, the inclination angle of the adjacent guide grooves is 5°, and the inclination angles of the guide grooves outward are 10°, 15°...), thus forming a continuous gradient layout.

[0079] Combined with reference Figure 2 and Figure 6 Each set of guide grooves is slidably provided with an adjusting slider 412c, and the adjusting slider 412c can move along the guide grooves. Each adjusting slider 412c is connected to a first adjusting plate 411.

[0080] It is easy to imagine that if the movement direction of the first adjustment plate 411 is not restricted, the first adjustment plate 411 may rotate along with the adjustment slider 412c.

[0081] To this end, a vertically extending slide groove is provided on the inner wall of the etching chamber 100 or the side wall of the square frame-shaped first gas homogenizing plate 310, and at least one end of the first adjustment plate 411 is slidably disposed in the slide groove. The slide groove can limit the movement direction of the first adjustment plate 411, so that the first adjustment plate 411 can only move in the vertical direction when subjected to force.

[0082] Specifically, when the gap between the first adjustment plates 411 needs to be reduced, the adjustment drive member 412b drives the adjustment shaft 412a to rotate counterclockwise, so that the adjustment sliders 412c move from the inclined distal end to the proximal end, and the adjustment sliders 412c drive the first adjustment plates 411 to move closer to each other.

[0083] When the gap between the first adjustment plates 411 needs to be increased, the adjustment driving member 412b drives the adjustment shaft 412a to rotate clockwise, so that the adjustment sliders 412c spread from the inclined proximal end to the distal end, and the adjustment sliders 412c drive the first adjustment plates 411 to move away from each other.

[0084] Since the multiple groups of guide grooves are distributed in a symmetrical fan shape, it can be known that the further away from the proximal end, the larger the spacing between the first adjustment plates 411; similarly, the further away from the distal end, the smaller the spacing between the first adjustment plates 411. Therefore, in actual operation, the rotation angle of the adjustment shaft 412a can be controlled according to the flow distribution requirements, so that the adjustment slider 412c stays at different positions in the guide groove, so that the first adjustment plates 411 have different spacings, thereby meeting more diverse air intake or air outlet needs.

[0085] In addition, by controlling the inclination angle of the guide groove, the adjustment plates can be always distributed at equal intervals, or the adjustment plates can be distributed at different intervals after the interval is adjusted. For example, the inclination of the guide groove arranged above the symmetry axis is greater than the inclination of the guide groove arranged below the symmetry axis; after the adjustment shaft 412a rotates and increases the gap between the first adjustment plates 411, the spacing between the adjustment plates becomes smaller from top to bottom; in this way, the gas flow distribution can be further regulated to promote the etching of the upper wafer better and more accurately.

[0086] Optionally, the multi-wafer etching device provided in the present application also includes a second gas uniforming plate 320, which is arranged in the etching chamber 100 and adjacent to the gas outlet 102; a plurality of second air holes are opened on the second gas uniforming plate 320, and the plurality of second air holes are evenly spaced along the vertical direction; a second air cavity 104 is formed between the second gas uniforming plate 320 and the gas outlet 102; the process steam that does not participate in the reaction and the by-products produced by etching will enter the second air cavity 104 through the second air holes during the discharge process, and the second air cavity 104 can buffer the fluctuation of the pumping speed and balance the pressure changes, thereby maintaining the stability of the air pressure in the etching chamber 100.

[0087] For details, please refer to Figure 1 and Figure 3 In the illustrated embodiment, the second air-distributing plate 320 and the first air-distributing plate 310 are symmetrically arranged in the left-right direction. The structure of the second air-distributing plate 320 is similar to that of the first air-distributing plate 310, and the details are not repeated here. The second air-distributing plate 320 is spaced apart from the left side wall where the air outlet 102 is located, and the space forms a sealed second air cavity 104.

[0088] During the etching process, the process steam that does not participate in the reaction and the by-products produced by the etching will flow from the etching area to the gas outlet 102 under the influence of the pressure difference between the inside and outside of the cavity caused by the vacuum equipment. During the outflow process, the gas will first pass through the gap between the third adjustment plate 431 and the fourth adjustment plate 441, and then contact the second uniform plate 320. The second uniform plate 320 can prevent the gas from rushing directly to the gas outlet 102, thereby stabilizing the air pressure near the gas outlet 102. At the same time, the second air hole on the second uniform plate 320 can play the role of flow limiting and diversion, so that the gas can evenly enter the second gas cavity 104. The second gas cavity 104 can use its own spatial volume to buffer the incoming gas.

[0089] When the vacuum equipment is working, if the pumping speed fluctuates, the gas in the second gas cavity 104 can replenish or adjust the pressure to a certain extent, so as to avoid a large fluctuation of the gas pressure in the etching chamber 100 due to a sudden change in the pumping speed. For example, when the pumping speed suddenly increases, the gas stored in the second gas cavity 104 can be quickly replenished to prevent a sudden drop in the gas pressure in the etching area; when the pumping speed decreases, the second gas cavity 104 can temporarily store excess gas to avoid a sudden increase in the gas pressure in the etching area, thereby maintaining a stable gas pressure in the etching chamber 100.

[0090] The arrangement of the second gas uniforming plate 320 and the second gas cavity 104 effectively solves the problem of gas pressure fluctuation, which is conducive to the etching reaction being carried out in a stable gas pressure environment.

[0091] Optionally, the multi-wafer etching apparatus provided in the present application further includes a temperature control mechanism, and the temperature control mechanism is used to heat the etching chamber 100 to maintain the temperature in the etching chamber 100 at 60° C.

[0092] The VHF process has the risk of low temperature liquefaction corrosion. Maintaining the ambient temperature in the etching chamber 100 at 60° C. can effectively maintain the gaseous state of the process steam and ensure that the etching continues and proceeds normally.

[0093] The temperature control mechanism can adopt any structure capable of achieving heating, such as a heating rod, a heating wire, etc.

[0094] Due to the risk of corrosion in the cavity, the temperature control mechanism is preferably arranged outside the cavity or in the cavity wall.

[0095] Optionally, the temperature control mechanism includes a heating belt, and each outer wall of the etching chamber 100 is attached with a heating belt, so as to fully heat the etching chamber 100 and ensure that the temperature in the etching chamber 100 is uniform everywhere.

[0096] Specifically, a resistance wire is provided in the heating belt, and the resistance wire generates heat when powered on, and the heat can be transferred to the cavity wall in contact with it through heat conduction, thereby increasing the temperature in the cavity from the outside to the inside. During the etching process, the heating belt works continuously and can automatically adjust the heating power according to the temperature data fed back by the temperature sensor in the etching cavity 100, ensuring that the temperature in the etching cavity 100 is always maintained at the set 60°C, providing a stable temperature environment for wafer etching.

[0097] More specifically, to ensure comprehensive heating, the outer wall of the etching chamber 100 is covered with heating tape, except for the material inlet and outlet (such as the wafer inlet and outlet, the air inlet 101, and the air outlet 102). By arranging the heating tape on the outer wall of the etching chamber 100, the heat can be transferred to the etching chamber 100 more evenly, avoiding the problem of local overheating or overcooling.

[0098] A stable and uniform temperature environment also helps to stabilize the chemical reaction between the process vapor and the wafer surface, which helps to improve the accuracy and consistency of etching.

[0099] Optionally, the heating belt is firmly attached to the outer wall of the etching chamber 100 by a high temperature resistant adhesive to ensure that the heat transfer efficiency between the heating belt and the outer wall is maximized.

[0100] Optionally, a heating tape is attached to the air intake duct.

[0101] Hydrofluoric acid is highly corrosive, especially in liquid form, but gaseous hydrofluoric acid (such as hydrogen fluoride vapor) is less corrosive. A heating belt is installed on the air inlet pipe to maintain a high temperature (above 55°C) in the air inlet pipe, which can prevent the process steam from being cooled and liquefied during circulation.

[0102] During the etching process, the heating belt on the air inlet pipe works continuously to ensure that the process steam remains in a gaseous state during transportation, thereby reducing the corrosion risk of liquid hydrofluoric acid and ensuring that the process steam can stably enter the etching chamber 100 and participate in the reaction.

[0103] Optionally, a heating tape is attached to the air outlet duct.

[0104] If the byproducts of etching and unreacted process steam are cooled and liquefied during the discharge process, there will not only be a risk of corrosion, but they may also block the exhaust pipe and affect the vacuum effect. In severe cases, it may even cause equipment failure.

[0105] Installing a heating belt on the gas outlet pipe can effectively prevent gas condensation and ensure smooth exhaust.

[0106] Optionally, the heating belt is wound along the outer wall of the pipeline and focused on covering key parts of the pipeline (such as connection parts and bends where temperature drop is likely to occur) to ensure that the entire pipeline can be fully heated.

[0107] Optionally, the air inlet pipe and / or the air outlet pipe are double-layer pipes, the inner pipe is used for ventilation, and the heating belt is arranged between the inner and outer pipes; the interlayer between the inner and outer pipes is vacuumed, or the interlayer between the inner and outer pipes is filled with insulation material, which is beneficial to reduce heat loss and maintain the heating effect.

[0108] Optionally, the temperature control mechanism further includes a heating wire, the etching chamber 100 includes an outer jacket and an inner liner, the outer jacket is made of metal material, the inner liner is made of high temperature resistant and corrosion resistant material, and the heating wire is embedded between the outer jacket and the inner liner.

[0109] Specifically, the outer jacket is made of stainless steel (such as 316L) or aluminum alloy, which has the advantages of high mechanical strength, low cost, and easy processing.

[0110] The lining is made of quartz or nickel-based alloy (such as Hastelloy C-276). In this way, the lining is not easily corroded even if it is directly in contact with corrosive gases (such as HF, ethanol). At the same time, the temperature resistance of quartz can exceed 1000℃, or the temperature resistance of nickel-based alloy can exceed 500℃, which is safer to use in cavities that need to be heated.

[0111] The quartz liner can be fixed to the outer jacket by mechanical clamps or high temperature resistant adhesives; the nickel-based alloy liner can be connected to the outer jacket by welding or bolts. The liner completely covers the inner wall of the outer jacket to prevent corrosive gases from contacting the outer jacket.

[0112] Installing the heating wire between the outer jacket and the inner liner does not hinder the heating of the inner liner and the inner cavity, and can prevent the heating wire from being exposed to a corrosive environment or being exposed to the outside, causing heat overflow and affecting the heating effect.

[0113] Optionally, the heating wires are distributed in a mesh or spiral shape, which can fully cover the lining and ensure heating uniformity.

[0114] Optionally, the etching chamber 100 is divided into multiple heating zones (such as top, bottom, left side, and right side), and each heating zone is configured with a set of independent PID controllers and thermocouples, which can provide real-time feedback on the temperature of each position to facilitate targeted adjustment of the power of the temperature control mechanism.

[0115] Optionally, a lifting movable chamber 510 is provided below the etching chamber 100, a lifting platform 520 is provided in the lifting movable chamber 510, and the wafer rack 200 is arranged on the lifting platform 520; after completing the etching of a batch of wafers, the lifting platform 520 descends with the wafer rack 200, so that the wafer rack 200 enters the lifting movable chamber 510, and a wafer inlet and outlet are provided on the lifting movable chamber 510, through which the wafers after etching and the wafers to be etched can be unloaded and loaded; after the wafer rack 200 loads the wafers to be etched, the lifting platform 520 ascends with the wafer rack 200, so that the wafer rack 200 enters the etching chamber 100, so that the wafers can be etched.

[0116] For details, please refer to Figure 7 In the illustrated embodiment, the bottom of the etching chamber 100 is connected to the lifting chamber 510, and the lifting platform 520 can move in the two chambers by vertical displacement. The lifting chamber 510 can accommodate the lifting platform 520 and the wafer rack 200, providing an operating space for loading and unloading wafers. A wafer inlet and outlet are provided on one side of the lifting chamber 510, and external wafer loading and unloading equipment (such as a robot) can interact with the wafer inlet and outlet.

[0117] The wafer rack 200 carries a batch of wafers. After etching is completed in the etching chamber 100, the lifting platform 520 descends, allowing the wafer rack 200 to enter the lifting movable chamber 510. Through the wafer inlet and outlet, the wafer loading and unloading equipment can take out the wafers that have been etched. After a batch of wafers are taken out, the wafer loading and unloading equipment can place new wafers to be etched into the lifting movable chamber 510. After the wafer rack 200 loads a new batch of wafers, the lifting platform 520 rises, allowing the wafer rack 200 to enter the etching chamber 100.

[0118] It is easy to understand that if the wafer loading and unloading operation is performed in the etching chamber 100, it may affect the gas environment, temperature and other parameters in the chamber, thereby interfering with the stability of etching. The lifting and lowering chamber 510 is provided to transfer the loading and unloading operation to the lifting and lowering chamber 510, so as to avoid the wafer inlet and outlet being provided on the etching chamber 100, thereby solving the problems of gas leakage, heat dissipation, and uneven temperature in the etching area caused by the existence of the wafer inlet and outlet.

[0119] Optionally, the wafer rack 200 is detachably arranged on the lifting platform 520; the wafer rack 200 carrying the etched wafers is unloaded to achieve rapid unloading; and the wafer rack 200 carrying the wafers to be etched is loaded to achieve rapid loading.

[0120] The wafer rack 200 is detachable compared to the lifting platform 520. After etching is completed, the wafer rack 200 is lowered into the lifting activity chamber 510, and the wafer rack 200 is removed through the wafer inlet and outlet, and all the wafers can be taken out at the same time. Then, a new wafer rack 200 carrying the wafers to be etched is loaded into the lifting platform 520, and the next round of etching can be started immediately.

[0121] The detachable design combined with the lifting function enables rapid loading and unloading of wafers, which can shorten the replacement time of each batch of wafers and thus improve overall production efficiency.

[0122] In one embodiment, a card block is provided on the lifting platform 520, and the shape of the card block can be a right-angle trapezoid or an L-shape; a card slot is provided at the bottom of the wafer rack 200. When installing, the card slot at the bottom of the wafer rack 200 is aligned with the card block, and the wafer rack 200 is pressed down and pushed, and the card block is inserted into the card slot to complete the installation. When disassembling, the wafer rack 200 is pushed in the opposite direction to disengage the card block from the card slot, and the wafer rack 200 can be removed from the lifting platform 520.

[0123] In another embodiment, a plurality of corresponding threaded holes are provided on the lifting platform 520 and the wafer rack 200. During installation, the threaded holes on the lifting platform 520 are aligned with the threaded holes on the wafer rack 200, and the two can be fastened together using screws. During disassembly, the wafer rack 200 and the lifting platform 520 can be separated by unscrewing the screws.

[0124] In another embodiment, a magnet is disposed on one of the lifting platform 520 and the wafer rack 200, and a metal sheet is disposed on the other. During installation, the magnet attracts the metal sheet to fix the two. During disassembly, the external force overcomes the magnetic attraction to release the fixation of the two.

[0125] The present application does not limit the specific connection method between the wafer rack 200 and the lifting platform 520 .

[0126] Optionally, the lifting platform 520 includes: a table 521, which is used to install the wafer rack 200 and can perform lifting and lowering movements under the drive of a lifting drive; a cover 522, which is arranged directly above the table 521; a connecting rod 523, which is used to connect the table 521 and the cover 522; when the wafer rack 200 is placed on the lifting platform 520, the wafer rack 200 is located between the table 521 and the cover 522.

[0127] The lifting drive can be any structure such as a hydraulic cylinder or an electric cylinder that can drive the table 521 to move up and down in the vertical direction. The lifting drive can be arranged in the lifting activity chamber 510 (during the etching process, the lifting activity chamber 510 is isolated from the etching chamber 100, and the process steam will not enter the lifting activity chamber 510, and will not corrode the lifting drive), or it can be arranged outside the lifting activity chamber 510.

[0128] For details, please refer to Figure 7 In the illustrated embodiment, the table 521 and the cover 523 are arranged opposite to each other in the vertical direction, and the two are fixed by three groups of connecting rods 523. One group of connecting rods 523 is arranged on the side of the table 521 away from the wafer inlet and outlet, and the other two groups of connecting rods 523 are arranged opposite to each other in the left and right directions. When loading, the wafer rack 200 is passed between the table 521 and the cover 523 through the wafer inlet and outlet, and the wafer rack 200 can pass between the two groups of connecting rods 523 on the left and right and abut against the opposite group of connecting rods 523. When the wafer rack 200 abuts against the connecting rods 523, it can be prompted to be placed in place.

[0129] Optionally, the multi-wafer etching device also includes an auxiliary gas supply pipeline, which is arranged in the lifting platform 520 and connected to the process steam supply equipment; the cover 522 is provided with a first gas outlet on the bottom surface facing the platform 521, and the first gas outlet is connected to the auxiliary gas supply pipeline, and / or, the connecting rod 523 is provided with a second gas outlet on the side facing the wafer rack 200, and the second gas outlet is connected to the auxiliary gas supply pipeline; during the etching process, the process steam can be sprayed toward the wafer through the first gas outlet and / or the second gas outlet.

[0130] In one embodiment, the bottom surface of the cover 522 is provided with a plurality of first air outlet holes, and the plurality of first air outlet holes are equally spaced inside along the circumferential direction; the diameter of the circle where the plurality of first air outlet holes are located is slightly larger than the diameter of the wafer. When the process steam is ejected through the first air outlet holes, a circle of air curtain can be formed so as to act on the wafer in an all-round manner. At the same time, the process steam ejected through the first air outlet holes mainly acts on the upper wafer, which can promote the etching of the upper wafer more accurately.

[0131] When multiple groups of connecting rods 523 are provided between the platform 521 and the cover 523, the second air outlet holes may be provided on only one group of connecting rods 523, or on multiple groups of connecting rods 523. Increasing the number of connecting rods 523 with second air outlet holes can optimize the coverage of process steam and improve the gas receiving effect of the wafer.

[0132] In one embodiment, referring to Figure 7 Three groups of connecting rods 523 are arranged between the platform 521 and the cover 523. A group of connecting rods 523 arranged on the side of the platform 521 away from the wafer inlet and outlet is provided with a plurality of second air outlets. The plurality of second air outlets are evenly spaced along the vertical direction, and any second air outlet is aimed at a wafer. When each wafer in the wafer rack 200 is facing a second air outlet, the second air outlet sprays process steam, and each wafer can be gassed nearby, thereby comprehensively improving the etching efficiency. It is also possible to open a second air outlet only for the upper wafer. When necessary, the second air outlet is used to replenish gas to the several wafers located on the upper layer, which can promote the etching of the upper wafer.

[0133] In a specific embodiment, a first air outlet is provided on the bottom surface of the cover 522, and a second air outlet is provided on the side of the connecting rod 523. The platform 521, the connecting rod 523 and the cover 522 are all hollow structures, and the hollow inner cavities of the three are interconnected. At this time, the connected hollow inner rings constitute an auxiliary air supply pipeline. A valve is provided on the auxiliary air supply pipeline. When air replenishment is required, the valve is opened, and the process steam can be passed into the connecting rod 523 and the cover 522 along the auxiliary air supply pipeline, and finally sprayed toward the wafer through the first air outlet and the second air outlet.

[0134] In actual use, it may be necessary to eject air only through the first air outlet, or only through the second air outlet, or it may be necessary to eject air through the first air outlet and the second air outlet at different times.

[0135] At this time, two hollow flow channels can be constructed in the platform 521, the connecting rod 523 and the cover 522 as auxiliary air supply pipes, one of which is connected to the first air outlet, and the other is connected to the second air outlet; a valve is provided on each of the two hollow flow channels, and the corresponding valve can be opened to spray air as needed.

[0136] In another embodiment, the platform 521, the connecting rod 523 and the cover 522 are all hollow structures, and the auxiliary air supply pipeline is a hose, which is inserted into the hollow inner cavity of the three. In this case, two sets of soft groups are inserted in the lifting platform 520, one set of hoses is connected to the first air outlet, and the other set of hoses is connected to the second air outlet; a valve is respectively provided on the two hoses, and the corresponding valve can be opened to spray air as needed.

[0137] During the simultaneous etching of multiple wafers, the process vapor will be deposited downward due to the influence of gravity, resulting in a higher etching rate for the lower wafer than for the upper wafer. By setting the first air outlet in the cover 522, targeted gas replenishment can be performed for the upper wafer. By increasing the process vapor flow around the upper wafer, the etching efficiency of the upper and lower wafers can be optimized and the etching difference can be reduced. When only the second air outlet is set for the upper wafer, a similar effect can also be achieved. Conventional etching methods may also lead to inconsistent etching degrees between wafers. By providing second air outlets on the connecting rod 523 and making the second air outlets correspond to the wafers one by one, each wafer can be purged with more accurate process steam, which is beneficial to improving the etching effect of the wafer and ensuring the etching uniformity of the wafer.

[0138] Providing the first air outlet and the second air outlet increases the purge path of the process steam, which can increase the contact area and reaction opportunity between the wafer and the process steam, especially promoting the etching of the upper wafer, which can effectively improve the overall etching efficiency and help shorten the etching time.

[0139] Optionally, a connecting passage is provided between the etching chamber 100 and the lifting movable chamber 510, and the lifting platform 520 and the wafer rack 200 can move between the etching chamber 100 and the lifting movable chamber 510 through the connecting passage; after the lifting platform 520 carries the wafer rack 200 into the etching chamber 100, the platform 521 can seal the connecting passage to prevent process steam from entering the lifting movable chamber 510; after the lifting platform 520 carries the wafer rack 200 into the lifting movable chamber 510, the cover 523 can seal the connecting passage to avoid interference between the processing operations in the lifting movable chamber 510 and the etching chamber 100.

[0140] For details, please refer to Figure 7 In the illustrated embodiment, the platform 521 and the cover 523 are symmetrically arranged in the vertical direction, and both are arranged in a truncated cone shape. The connecting passage is a cylindrical passage, and the inner diameter of the connecting passage is smaller than the outer diameter of the platform 521 and the cover 523, so that the platform 521 and the cover 523 cannot enter the connecting passage. When the lifting platform 520 rises, the platform 521 can abut against the connecting passage from bottom to top, thereby prompting that it has risen to the right position. When the lifting platform 520 descends, the cover 523 can abut against the connecting passage from top to bottom, thereby prompting that it has descended to the right position.

[0141] In order to improve the sealing between the platform 521 and the cover 523 when they abut against the connecting channel, a sealing ring can be embedded on the front side of the platform 521 abutting against the connecting channel, and a sealing ring can be embedded on the back side of the cover 523 abutting against the connecting channel. The sealing ring is deformed under pressure and can make up for the gap that may exist after the abutment, thereby ensuring the sealing effect.

[0142] During the etching process, the stage 521 seals the communication channel, which can prevent process steam from entering the lifting chamber 510, thereby protecting the equipment parts in the lifting chamber 510, and ensure the stability of the process environment in the etching chamber 100 so that etching can proceed normally.

[0143] When the wafer is loaded or unloaded, the cover 523 seals the communication channel, so that the etching chamber 100 is separated from the lifting and lowering chamber 510. Cleaning, process pretreatment and other operations can be performed in the independently sealed etching chamber 100, such as cleaning residual process steam and by-products, checking and adjusting the equipment in the chamber, etc. The processing operations of the two chambers do not interfere with each other, which helps to improve the operation synchronization of the equipment and reduce the idle time of the equipment.

[0144] Optionally, a cover is provided on the top of the wafer rack 200 , and an auxiliary air hole is provided on a side of the cover facing the wafer, and the auxiliary air hole is connected to a process steam supply device.

[0145] The auxiliary air hole provided on the cover is similar to the first air outlet hole provided on the cover 522 in the above text, and its function is to provide targeted air supply to the upper wafer.

[0146] In one embodiment, the total etching time is 2N. After the etching time exceeds N, at the air inlet end, the gap between the first adjustment plates 411 is increased and the gap between the second adjustment plates 421 is decreased. At the air outlet end, the gap between the third adjustment plates 431 is increased and the gap between the fourth adjustment plates 441 is decreased. At the same time, the auxiliary air holes are enabled to allow the process steam to spray toward the wafer from top to bottom, which can effectively improve the etching difference between the upper and lower wafers.

[0147] In a specific embodiment, the VHF process has a total process time of 5 minutes. After etching for 3 minutes, the etching speed of the wafer from bottom to top becomes slower and slower. The gap between the first adjustment plates 411 is increased to increase the amount of process steam rushing to the upper wafer; the gap between the second adjustment plates 421 is reduced to reduce the amount of process steam rushing to the lower wafer; at the same time, the gap between the third adjustment plates 431 is increased and the gap between the fourth adjustment plates 441 is reduced to maintain stable airflow. After etching for 5 minutes, the measurement results show that the overall etching rate is basically the same, with a small difference, and the single-wafer etching uniformity is also improved, all below 5%.

[0148] In another embodiment, the VHF process has a total process time of 5 minutes. After etching for 3 minutes, the etching speed of the wafer becomes slower and slower from bottom to top. The auxiliary air holes are enabled so that the process steam is sprayed from top to bottom onto the wafer. After etching for 5 minutes, the measurement results show that the overall etching rate is basically the same, and the uniformity is also improved, all below 5%.

[0149] In another embodiment, the VHF process has a total process time of 5 minutes. After etching for 3 minutes, the etching speed of the wafer becomes slower and slower from bottom to top. The gap between the first adjustment plates 411 increases, the gap between the second adjustment plates 421 decreases, the gap between the third adjustment plates 431 increases, and the gap between the fourth adjustment plates 441 decreases. At the same time, the auxiliary air holes are enabled to spray the process steam from top to bottom onto the wafer. After etching for 5 minutes, the measurement results show that the overall etching rate is basically the same, with a small difference, and the single-wafer etching uniformity is also improved, all below 3%.

[0150] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A multi-wafer etching device, characterized in that: include: An etching chamber, with an air inlet on one side and an air outlet on the other side opposite thereto; The wafer rack is arranged in the etching chamber and is a multi-layer support structure; A first air intake regulating mechanism is provided in the etching chamber and located at one side of the air intake port, the first air intake regulating mechanism comprises a plurality of first regulating plates and a first regulator, the plurality of first regulating plates are arranged at intervals in the vertical direction, and the first regulator is used to adjust the gap between the first regulating plates; A second air intake regulating mechanism is also arranged in the etching chamber and located at one side of the air intake port, the second air intake regulating mechanism comprises a plurality of second regulating plates and a second regulator, the plurality of second regulating plates are arranged at intervals in the vertical direction, the second regulator is used to adjust the gap between the second regulating plates, and the first regulating plate and the second regulating plate are arranged side by side in the vertical direction; A first gas outlet regulating mechanism is disposed in the etching chamber and adjacent to the gas outlet, the first gas outlet regulating mechanism comprises a plurality of third regulating plates and a third regulator, the plurality of third regulating plates are arranged at intervals in the vertical direction, the third regulator is used to adjust the gap between the third regulating plates, the first regulating plate and the third regulating plate are arranged opposite to each other in the horizontal direction, and the wafer rack is located between the first regulating plate and the third regulating plate; The second gas outlet regulating mechanism is also arranged in the etching chamber and adjacent to the gas outlet. The second gas outlet regulating mechanism includes a plurality of fourth regulating plates and a fourth regulator. The plurality of fourth regulating plates are arranged at intervals in the vertical direction. The fourth regulator is used to adjust the gap between the fourth regulating plates. The second regulating plate and the fourth regulating plate are arranged opposite to each other in the horizontal direction. The wafer rack is located between the second regulating plate and the fourth regulating plate. The third regulating plate and the fourth regulating plate are arranged side by side in the vertical direction.

2. The multi-wafer etching device according to claim 1, characterized in that: The first regulator, the second regulator, the third regulator and / or the fourth regulator include: An adjusting shaft is rotatably disposed in the etching chamber and extends in a vertical direction. The adjusting shaft is provided with a plurality of symmetrically distributed guide grooves. A group of guide grooves serving as a symmetry axis extends horizontally along the circumference of the adjusting shaft. The other guide grooves extend obliquely relative to the symmetry axis, and the inclination angle increases gradually from both sides of the symmetry axis to form a continuously gradient layout. An adjusting driving member, used for driving the adjusting shaft to rotate; A plurality of adjusting sliders, wherein one adjusting slider is slidably disposed in any of the guide grooves, and any of the adjusting sliders is connected to an adjusting plate; When the distribution of the inlet or outlet air flow needs to be changed, the adjustment shaft is driven to rotate by the adjustment drive member, and the adjustment slider can slide along the guide groove. Under the influence of the guide groove layout, a set of adjustment plates connected to the adjustment slider can move in the vertical direction and change the spacing.

3. The multi-wafer etching device according to claim 1, characterized in that: Also includes: A first air-distributing plate is disposed in the etching chamber and adjacent to the air inlet. A plurality of first air holes are formed on the first air-distributing plate. The plurality of first air holes are evenly spaced in the vertical direction. A first air cavity is formed between the first air-distributing plate and the air inlet. The first air inlet regulating mechanism and the second air inlet regulating mechanism are both located on a side of the first air-distributing plate away from the air inlet. A second gas uniforming plate is arranged in the etching chamber and adjacent to the gas outlet. A plurality of second air holes are opened on the second gas uniforming plate. The plurality of second air holes are evenly spaced along the vertical direction. A second air cavity is formed between the second gas uniforming plate and the gas outlet.

4. The multi-wafer etching device according to claim 1, characterized in that: It also includes a temperature control mechanism, which is used to heat the etching chamber to maintain the temperature in the etching chamber at 60° C. The temperature control mechanism comprises a heating belt, and each outer wall of the etching chamber is attached with the heating belt, so as to fully heat the etching chamber and ensure that the temperature in the etching chamber is uniform everywhere.

5. The multi-wafer etching device according to claim 4, characterized in that: The air inlet is connected to the process steam supply equipment through the air inlet pipe, and the air outlet is connected to the vacuum equipment through the air outlet pipe. The heating belt is also attached to the air inlet pipe and / or the air outlet pipe; And / or, the temperature control mechanism also includes a heating wire, the etching chamber includes an outer jacket and an inner liner, the outer jacket is made of metal material, the inner liner is made of high temperature resistant and corrosion resistant material, and the heating wire is embedded between the outer jacket and the inner liner.

6. The multi-wafer etching device according to claim 1, characterized in that: A lifting activity chamber is provided below the etching chamber, a lifting platform is provided in the lifting activity chamber, and the wafer is mounted on the lifting platform; After a batch of wafers are etched, the lifting platform and the wafer rack are lowered, so that the wafer rack enters the lifting activity chamber. The lifting activity chamber is provided with a wafer inlet and outlet, through which the unloading of etched wafers and the loading of wafers to be etched can be realized; After the wafer rack is loaded with the wafer to be etched, the lifting platform carries the wafer rack up, so that the wafer rack enters the etching chamber, so that the wafer can be etched.

7. The multi-wafer etching device according to claim 6, characterized in that: The wafer rack is detachably arranged on the lifting platform; Unloading the wafer rack carrying the etched wafers to achieve rapid unloading; The wafer rack carrying the wafer to be etched is loaded to achieve rapid loading.

8. The multi-wafer etching device according to claim 7, characterized in that: The lifting platform comprises: A platform portion, used for mounting the wafer rack, and capable of performing lifting motion driven by a lifting drive; A cover portion, disposed directly above the platform portion; A connecting rod, used to connect the platform portion and the cover portion; When the wafer rack is placed on the lifting platform, the wafer rack is located between the platform and the cover; The multi-wafer etching device further comprises an auxiliary gas supply pipeline, which is arranged in the lifting platform and connected to the process steam supply equipment; The bottom surface of the cover facing the platform is provided with a first air outlet, the first air outlet is connected to the auxiliary air supply pipeline, and / or the side surface of the connecting rod facing the wafer rack is provided with a second air outlet, the second air outlet is connected to the auxiliary air supply pipeline; During the etching process, process steam can be sprayed toward the wafer through the first gas outlet hole and / or the second gas outlet hole.

9. The multi-wafer etching device according to claim 8, characterized in that: A communication channel is provided between the etching chamber and the lifting and moving chamber, and the lifting platform and the wafer rack can move between the etching chamber and the lifting and moving chamber through the communication channel; After the lifting platform carries the wafer rack into the etching chamber, the platform portion can seal the communication channel to prevent process steam from entering the lifting activity chamber; After the lifting platform carries the wafer rack into the lifting activity chamber, the cover can seal the communication channel to avoid interference between the processing operations in the lifting activity chamber and the etching chamber.

10. The multi-wafer etching device according to claim 1, characterized in that: A cover is provided on the top of the wafer rack, and an auxiliary air hole is provided on a side of the cover facing the wafer, and the auxiliary air hole is connected to a process steam supply device; The total etching time is 2N. After the etching time exceeds N, at the air inlet end, the gap between the first adjustment plates is increased and the gap between the second adjustment plates is decreased. At the air outlet end, the gap between the third adjustment plates is increased and the gap between the fourth adjustment plates is decreased. At the same time, the auxiliary air holes are enabled to allow the process steam to spray toward the wafer from top to bottom, which can effectively improve the etching difference between the upper and lower wafers.

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