Etching method

Abstract

The invention belongs to the technical field of etching, and discloses an etching method. The etching device comprises a reaction chamber, a wafer carrier, a fluid supply part and a heating component, wherein the wafer carrier is arranged in the reaction chamber, a circulation channel is arranged in the wafer carrier, and a liquid inlet and a liquid outlet communicated with the circulation channel are arranged on the wafer carrier; the fluid supply part connects the liquid inlet and the liquid outlet; the heating component is connected between the liquid inlet and the fluid supply part, and the heating component is configured to increase the temperature of the fluid entering the circulation channel; the etching method uses the etching device to perform etching on the same wafer carrier in a reaction chamber, so that a low-temperature fluid enters the wafer carrier to generate an ammonium salt byproduct; then the temperature is increased by the heating component, and the ammonium salt byproduct is volatilized, so that there is no need to equip two reaction chambers, so that the output and volatilization of the ammonium salt byproduct are completed in one reaction chamber, the floor space is reduced, and the efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of etching, and in particular to an etching method. Background Art

[0002] In the field of ammonium salt etching for semiconductor manufacturing, the principle is to introduce NF into the plasma. 3 , H 2 and N 2 The byproduct of the reaction is ammonium salt generated by reacting with the native oxide on the wafer. The chemical reaction formula is 4HF+2NH 4 F+SiO 2 →(NH 4 ) 2 SiF 6 +2H 2 O. Generated (NH 4 ) 2 SiF 6 The byproducts can be decomposed into steam at high temperatures, and this steam can be pumped away by a vacuum pump. Existing ammonium salt etching equipment is equipped with two chambers, one chamber is equipped with a low-temperature wafer tray for the generation of ammonium salts. The other chamber is equipped with a high-temperature wafer tray for the decomposition of ammonium salts. This requires two reaction chambers, which is a high-cost solution. In addition, the two chambers also cause the entire ammonium salt etching equipment to occupy too much space. Summary of the invention

[0003] The object of the present invention is to provide an etching device and an etching method, which can realize the generation and decomposition of ammonium salt in one reaction chamber without the need to equip two reaction chambers, thereby reducing the floor space and improving production efficiency.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] An etching device, comprising:

[0006] reaction chamber;

[0007] A wafer carrier, the wafer carrier is arranged in the reaction chamber to carry the wafer; a circulation channel is arranged in the wafer carrier, and the wafer carrier is provided with a liquid inlet and a liquid outlet communicated with the circulation channel;

[0008] A fluid supply member, the fluid supply member connecting the liquid inlet and the liquid outlet to circulate the fluid;

[0009] A heating component is connected between the liquid inlet and the fluid supply component, and is configured to increase the temperature of the fluid entering the circulation channel.

[0010] In some embodiments, the heating component includes a heating end and a thermocouple, and the heating end is connected to the thermocouple via a temperature controller.

[0011] In some embodiments, the fluid supply is a water chiller.

[0012] In some embodiments, a flow controller is further included, and the flow controller is disposed between the liquid inlet and the fluid supply member.

[0013] An etching method, using the etching device as described above to etch a wafer, comprises the following steps:

[0014] S1, etching the wafer on the wafer carrier at a first temperature to produce ammonium salt byproducts on the wafer;

[0015] S2, raising the temperature of the wafer carrier from the first temperature to a second temperature;

[0016] S3, volatilizing the ammonium salt byproduct on the wafer at a second temperature by causing the wafer carrier to volatilize;

[0017] S4. After the ammonium salt by-product has been volatilized, the temperature of the wafer carrier is reduced from the second temperature to the first temperature.

[0018] In some embodiments, the first temperature is 10°C-40°C.

[0019] In some embodiments, the second temperature is 80°C-140°C.

[0020] In some embodiments, S2 is specifically:

[0021] Liquid is supplied to the circulation channel at a first flow rate, and the heating component is heated; when the temperature of the wafer carrier reaches 80% of the second temperature, PID temperature control is performed to the second temperature.

[0022] In some embodiments, S4 is specifically:

[0023] Liquid is supplied to the circulation channel at a second flow rate, and the heating component stops heating, wherein the second flow rate is greater than the first flow rate.

[0024] In some embodiments, the first flow rate is 0.2 L / min-5 L / min, and the second flow rate is 5 L / min-15 L / min.

[0025] Beneficial effects of the present invention:

[0026] The etching device and etching method can be used to perform etching on the same wafer carrier in a reaction chamber, and a low-temperature fluid is supplied to the circulation channel of the wafer carrier through a fluid supply component, so that the wafer is etched at a relatively low temperature to form (NH 4 ) 2 SiF 6 , which is the by-product of ammonium salt; then the temperature of the fluid is changed by the heating component to increase the temperature, and the temperature of the wafer carrier also increases accordingly. When the temperature reaches the volatilization temperature of the ammonium salt by-product, the ammonium salt by-product on the wafer volatilizes, thereby eliminating the need for two reaction chambers. The output and volatilization of the ammonium salt by-product are completed in one reaction chamber, which reduces the floor space and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of an etching device of the present invention;

[0028] Figure 2 is a schematic diagram of a heating component in the etching device of the present invention;

[0029] Figure 3 It is a flow chart of the etching method of the present invention.

[0030] In the figure:

[0031] 1. Reaction chamber; 11. Air inlet; 12. Air outlet; 2. Wafer carrier; 21. Circulation channel; 3. Fluid supply part; 4. Heating component; 41. Heating end; 42. Thermocouple; 43. Temperature controller; 5. Flow controller. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0036] like Figure 1 and Figure 2 As shown, the present invention provides an etching device, which includes a reaction chamber 1, a wafer carrier 2, a fluid supply part 3 and a heating component 4, wherein the wafer carrier 2 is arranged in the reaction chamber 1 to carry the wafer; a circulation channel 21 is arranged in the wafer carrier 2, and the wafer carrier 2 is provided with a liquid inlet and a liquid outlet connected to the circulation channel 21; the fluid supply part 3 connects the liquid inlet and the liquid outlet to circulate the fluid; the heating component 4 is connected between the liquid inlet and the fluid supply part 3, and the heating component 4 is configured to increase the temperature of the fluid entering the circulation channel 21.

[0037] The above structure is used to perform etching on the same wafer carrier in a reaction chamber 1. The low-temperature fluid enters the circulation channel 21 of the wafer carrier 2 through the fluid supply part 3, so that the wafer is etched at a relatively low temperature to form (NH 4 ) 2 SiF 6 , which is the by-product of ammonium salt; then the temperature of the fluid is changed by the heating component 4 to increase the temperature, and the temperature of the wafer carrier also increases accordingly. When the temperature reaches the volatilization temperature of the ammonium salt by-product, the ammonium salt by-product on the wafer volatilizes, thereby eliminating the need to equip two reaction chambers 1, so that the output and volatilization of the ammonium salt by-product are completed in one reaction chamber 1, which reduces the floor space and improves production efficiency.

[0038] It should be noted that the fluid supply part 3, the heating component 4 and the circulation channel 21 of the wafer carrier 2 are all connected through a delivery pipe. In this embodiment, the fluid is water. Based on this, the fluid supply part 3 uses a chiller, which can provide water at a lower temperature.

[0039] In some embodiments, the reaction chamber 1 is provided with an air inlet 11 and an air outlet 12, wherein the air inlet 11 is connected to a gas supply device to provide reaction gas into the reaction chamber 1; the air outlet 12 is connected to an exhaust device to extract the volatilized ammonium salt byproducts from the reaction chamber 1.

[0040] In some embodiments, the heating component 4 includes a heating end 41, a thermocouple 42 and a temperature controller 43, and the three are communicatively connected. The heating end 41 is used to heat the fluid, the thermocouple 42 can monitor the temperature of the fluid in real time, and the temperature controller 43 can adjust the heating power and heating time of the heating end 41 in real time according to the collected data of the thermocouple 42.

[0041] In some embodiments, the etching device is further provided with a flow controller 5, which is arranged between the liquid inlet and the fluid supply member 3; it can be specifically arranged between the fluid supply member 3 and the heating component 4, or between the heating component 4 and the liquid inlet, so as to accurately control the flow of the fluid entering the circulation channel 21, so as to more accurately control the process of heating or cooling. Further, the flow controller 5 can be connected to the temperature controller 43 in the heating component 4, so as to control the flow of the fluid according to the temperature adjustment.

[0042] The present invention also provides an etching method, which utilizes the above-mentioned etching device to etch a wafer, and comprises the following steps:

[0043] S1. Liquid is supplied to the wafer carrier 2 through the fluid supply part 3, so that the temperature of the fluid is maintained at the first temperature, and the reaction gas is introduced into the reaction chamber 1, so that the wafer carrier 2 can etch the wafer at the first temperature, so that the wafer produces ammonium salt byproducts; it should be noted here that since the optimal generation temperature of ammonium salt byproducts is 20℃-30℃, the first temperature can be maintained between 10℃-40℃. It can be understood that the operation of maintaining the fluid at the first temperature can be directly provided by the chiller at the first temperature state, that is, there is no need to heat it through the heating component 4; it can be understood that if the chiller cannot make the fluid lower than the first temperature, the heating component 4 can also be used for auxiliary heating.

[0044] S2, raising the temperature of the wafer carrier 2 from the first temperature to the second temperature at which the ammonium salt by-product can be volatilized; the specific operation is: supplying liquid to the circulation channel 21 at a first flow rate through the flow controller 5, and starting the heating component 4 to heat the fluid; wherein the first flow rate is smaller than the liquid supply flow rate in step S1, that is, supplying liquid at a smaller flow rate so that the temperature of the fluid can be quickly increased; illustratively, the first flow rate is 0.2L / min-5L / min; when the temperature of the fluid reaches 80% of the second temperature, PID temperature control is performed to the second temperature. PID temperature control is a prior art, which mainly uses staged temperature increase to quickly reach the second temperature, such as a step-by-step temperature increase of 10%-20%, and the specific details are not repeated.

[0045] S3. At the second temperature, the ammonium salt byproduct on the wafer is volatilized and extracted from the reaction chamber 1 through the gas outlet 12. It should be noted that the optimal volatilization temperature of the ammonium salt byproduct is 100°C-120°C, that is, the second temperature can be set between 80°C-140°C.

[0046] S4. After the ammonium salt byproducts are volatilized, it is necessary to be able to quickly prepare for the etching of the next wafer, that is, the temperature of the wafer carrier 2 needs to be reduced from the second temperature to the first temperature; in this step, in order to quickly reduce the temperature, the flow controller 5 supplies liquid to the circulation channel 21 at the second flow rate, and the heating component 4 is turned off, and then the second flow rate of the fluid flows through the circulation channel 21, so that the temperature of the wafer carrier 2 quickly returns to the first temperature. Exemplarily, the second flow rate is 5 L / min-15L / min.

[0047] Therefore, when the etching equipment and etching method are used, there is no need to equip two reaction chambers 1, so that the production and volatilization of the ammonium salt by-product are completed in one reaction chamber 1, which reduces the floor space and improves the production efficiency.

[0048] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An etching method, characterized in that: The etching device comprises a reaction chamber (1), a wafer carrier (2), a fluid supply component (3) and a heating component (4); the wafer carrier (2) is arranged in the reaction chamber (1) to carry a wafer; a circulation channel (21) is arranged in the wafer carrier (2), and the wafer carrier (2) is provided with a liquid inlet and a liquid outlet communicated with the circulation channel (21); the fluid supply component (3) connects the liquid inlet and the liquid outlet to circulate a fluid; the heating component (4) is connected between the liquid inlet and the fluid supply component (3), and the heating component (4) is configured to increase the temperature of the fluid entering the circulation channel (21); The etching method comprises the following steps: S1, causing the wafer carrier (2) to perform an etching process on the wafer at a first temperature, so that the wafer produces an ammonium salt byproduct; S2, raising the temperature of the wafer carrier (2) from the first temperature to a second temperature, supplying liquid to the circulation channel (21) at a first flow rate, and heating the heating component (4); when the temperature of the wafer carrier (2) reaches 80% of the second temperature, performing PID temperature control to the second temperature; S3, allowing the wafer carrier (2) to volatilize the ammonium salt byproduct on the wafer at a second temperature; S4, after the ammonium salt by-product has been volatilized, the temperature of the wafer carrier (2) is reduced from the second temperature to the first temperature, liquid is supplied to the circulation channel (21) at a second flow rate, and the heating component (4) stops heating, and the second flow rate is greater than the first flow rate.

2. The etching method according to claim 1, characterized in that: The heating component (4) comprises a heating end (41) and a thermocouple (42), and the heating end (41) and the thermocouple (42) are connected via a temperature controller (43).

3. The etching method according to claim 1, characterized in that: The fluid supply component (3) is a water chiller.

4. The etching method according to claim 1, characterized in that: It also comprises a flow controller (5), wherein the flow controller (5) is arranged between the liquid inlet and the fluid supply member (3).

5. The etching method according to claim 1, characterized in that: The first temperature is 10°C-40°C.

6. The etching method according to claim 1, characterized in that: The second temperature is 80°C-140°C.

7. The etching method according to claim 1, characterized in that: The first flow rate is 0.2 L / min-5 L / min, and the second flow rate is 5 L / min-15 L / min.

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