Dry etching method

Abstract

A dry etching method comprises the steps that a process chamber is provided, the process chamber comprises a lifting base and a spray head located above the lifting base, and the lifting base bears a part to be etched; the distance between the liftable base and the spray head is adjusted to be a preset process distance; and introducing etching gas into the process chamber through the spray head, and etching the to-be-etched part. According to the invention, the electrical property and the yield of the to-be-etched part can be improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular to a dry etching method. Background Art

[0002] In semiconductor etching, the uniformity of dry etching is affected by many factors, and the uniformity directly affects the electrical properties and yield of the semiconductor structure to be etched.

[0003] During the dry etching process, etching gas is introduced, and the gas distribution above the semiconductor structure to be etched will be affected by the suction force of the turbo pump, and the gas concentration of the etching gas acting on different areas of the semiconductor structure to be etched will be different. The actual adsorption of gas in different areas of the semiconductor structure to be etched is also different, resulting in differences in reaction rates during the etching process. After etching is completed, the etching uniformity of the semiconductor structure to be etched is affected, especially after dry etching, wet etching will lead to the amplification of this difference. Summary of the invention

[0004] The problem solved by the embodiments of the present invention is to provide a dry etching method, which is beneficial to improving the electrical properties and yield of the etched parts.

[0005] To solve the above problems, an embodiment of the present invention provides a dry etching method, including: providing a process chamber, including a liftable base, and a nozzle located above the liftable base, the liftable base carries a workpiece to be etched; adjusting the distance between the liftable base and the nozzle to a preset process distance; introducing etching gas into the process chamber through the nozzle, and etching the workpiece to be etched.

[0006] Optionally, in the step of providing a process chamber, the liftable base is movable in the longitudinal direction; in the step of adjusting the distance between the liftable base and the nozzle to a preset process distance, the liftable base is moved to a preset process position so that the distance between the liftable base and the nozzle is the preset process distance.

[0007] Optionally, in the step of providing the process chamber, the liftable base is movable in the longitudinal direction so that the adjustable distance between the liftable base and the nozzle is 20 mm to 50 mm.

[0008] Optionally, in the step of providing a process chamber, the process chamber also includes a pin device penetrating a liftable base; after introducing etching gas into the process chamber through a nozzle and etching the workpiece to be etched, the step further includes: lowering the liftable base to below the top of the pin device to transfer the workpiece to be etched onto the pin device.

[0009] Optionally, in the step of providing a process chamber, the process chamber also includes a vacuum device located on the bottom wall of the process chamber; in the step of introducing etching gas into the process chamber through a nozzle and etching the part to be etched, the process chamber is also vacuumed through the vacuum device.

[0010] Optionally, before introducing etching gas into the process chamber through the nozzle and etching the workpiece to be etched, the method further includes: heating the workpiece to be etched to a preset process temperature; and controlling the pressure in the process chamber to be a preset process pressure.

[0011] Optionally, the workpiece to be etched is heated to a preset process temperature via a liftable base.

[0012] Optionally, the step of heating the workpiece to be etched to a preset process temperature by means of a liftable base further includes: loading the pressure in the process chamber to a preset heating pressure.

[0013] Optionally, in the step of loading the pressure in the process chamber to a preset heating pressure, the preset heating pressure is greater than or equal to 1.8 T, and the loading time of the preset heating pressure is greater than or equal to 120 s.

[0014] Optionally, the step of loading the pressure in the process chamber to a preset heating pressure includes: introducing a pressure-controlled gas into the process chamber through a nozzle, so that the pressure in the process chamber is loaded to the preset heating pressure.

[0015] Optionally, in the step of introducing a pressure-controlled gas into the process chamber through a nozzle, the pressure-controlled gas includes a catalytic gas and an inert gas.

[0016] Optionally, in the step of introducing the pressure-controlled gas into the process chamber through the nozzle, the process flow rate of the catalytic gas is 30 sccm to 60 sccm, and the process flow rate of the inert gas is 50 sccm to 200 sccm.

[0017] Optionally, the step of controlling the pressure in the process chamber to a preset process pressure includes: introducing a pre-occupying gas into the process chamber through a nozzle, the process flow rate of the pre-occupying gas being equal to the preset process flow rate of the etching gas in the step of introducing the etching gas into the process chamber through the nozzle.

[0018] Optionally, in the step of introducing a pre-occupying gas into the process chamber through the showerhead, the pre-occupying gas includes an inert gas.

[0019] Optionally, in the step of introducing the etching gas into the process chamber through the nozzle, the etching gas replaces the pre-occupying gas and is introduced into the process chamber through the nozzle.

[0020] Optionally, after the etching gas is introduced into the process chamber through the nozzle and the workpiece to be etched is etched, the dry etching method further includes: purifying the process chamber to remove reaction products of etching the workpiece to be etched.

[0021] Optionally, the step of purifying the process chamber includes: controlling the pressure in the process chamber to 0T; and introducing a purge gas into the process chamber through a nozzle to purge the interior of the process chamber.

[0022] Optionally, in the step of introducing a purge gas into the process chamber through the showerhead, the purge gas includes an inert gas.

[0023] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0024] In the dry etching method provided in an embodiment of the present invention, the distance between the liftable base and the nozzle is adjusted to a preset process distance, etching gas is introduced into the process chamber through the nozzle, and the workpiece to be etched is etched; in the embodiment of the present invention, by adjusting the distance between the liftable base and the nozzle, the gas flow field effect above the workpiece to be etched after the nozzle introduces the gas can be adjusted, and based on the flexibility of adjusting the distance between the liftable base and the nozzle, the optimal distance between the liftable base and the nozzle for obtaining the optimal gas flow field can be set for different dry etching processes as the preset process distance, so that in the process chamber, the distance between the liftable base and the nozzle is adjusted to the preset process distance, so that during the etching process, the optimal gas flow field can be easily achieved above the workpiece to be etched, which is beneficial to improving the etching uniformity, and further beneficial to improving the electrical properties and yield of the workpiece to be etched. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of an embodiment of a plate dry etching method of the present invention;

[0026] Figures 2 to 8 It is a schematic structural diagram corresponding to each step in an embodiment of a dry etching method of the present invention. DETAILED DESCRIPTION

[0027] As can be seen from the background technology, in the current semiconductor manufacturing field, during the dry etching process, etching gas is introduced, and the gas distribution above the semiconductor structure to be etched will be affected by the suction force of the turbo pump, and finally the etching gas acts on the gas concentration of different areas of the semiconductor structure to be etched. The actual adsorption of gas in different areas of the semiconductor structure to be etched is also different, resulting in differences in reaction rates during the etching process. After etching is completed, the etching uniformity of the semiconductor structure to be etched is affected, especially after dry etching, wet etching will lead to the amplification of this difference.

[0028] The prior art improves the etching effect by adjusting the gas flow rate and the gas outlet position without considering the distance between the semiconductor structure to be etched and the nozzle, which ignores the influence of the gas flow rate and the gas pressure under different process recipes. As a result, different gas flow rates and gas pressures will have large differences in the optimal gas flow field position on the surface of the semiconductor structure to be etched, thus still causing the problem of poor etching uniformity of the semiconductor structure to be etched.

[0029] In order to solve the above technical problems, an embodiment of the present invention provides a dry etching method. Figure 1 , showing a flow chart of an embodiment of a dry etching method of the present invention.

[0030] In this embodiment, the dry etching method includes the following basic steps:

[0031] Step S1: providing a process chamber, including a liftable pedestal and a showerhead located above the liftable pedestal, wherein the liftable pedestal carries a workpiece to be etched;

[0032] Step S2: adjusting the distance between the liftable base and the nozzle to a preset process distance;

[0033] Step S3: introducing etching gas into the process chamber through the nozzle, and etching the workpiece.

[0034] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] Figures 2 to 8 It is a schematic structural diagram corresponding to each step in an embodiment of a dry etching method of the present invention.

[0036] refer to Figure 2 Step S1: Provide a process chamber 100, including a liftable pedestal 105 and a showerhead 106 located above the liftable pedestal 105, and the liftable pedestal 105 carries a workpiece 104 to be etched.

[0037] The process chamber 100 is used to provide a process space for performing semiconductor processes.

[0038] Specifically, in this embodiment, the process chamber 100 is used to perform a dry etching process.

[0039] The pedestal 105 is used to support the workpiece 104 to be etched.

[0040] In this embodiment, in the step of providing the process chamber 100 , the liftable susceptor 105 is movable in the longitudinal direction.

[0041] Correspondingly, the liftable base 105 is also used to move the workpiece 104 to be etched in the longitudinal direction to adjust the distance between the workpiece 104 to be etched and the nozzle 106 .

[0042] As an example, Figure 2 As shown, the movable range of the liftable base 105 in the longitudinal direction is d.

[0043] In the present embodiment, in the step of providing the process chamber 100 , the liftable base 105 is movable in the longitudinal direction so that the adjustable distance between the liftable base 105 and the shower head 106 is 20 mm to 50 mm.

[0044] The liftable base 105 is movable in the longitudinal direction, so that the adjustable distance between the liftable base 105 and the nozzle 106 is 20 mm to 50 mm, so that the workpiece 104 to be etched is not prone to the problem of the distance between the workpiece 104 to be etched and the nozzle 106 being too small, thereby affecting the process and being damaged. At the same time, the liftable base 105 has a large movable distance in the longitudinal direction, so that the adjustment range of the distance between the workpiece 104 to be etched and the nozzle 106 is large, so that the flexible adjustment of the workpiece 104 to be etched can be widely applied to more types of dry etching processes, thereby improving the applicability of the dry etching method of this embodiment.

[0045] As an example, Figure 2 As shown, the liftable base 105 is movable in the longitudinal direction, so that the adjustable distance between the liftable base 105 and the nozzle 106 is d1 to d2, d1 is 20 mm, d2 is 50 mm, specifically, the distance between the liftable base 105 and the nozzle 106 can be 20 mm, 30 mm, 40 mm, 50 mm, etc.

[0046] The showerhead 106 is used to introduce gas into the process chamber 100 .

[0047] In this embodiment, the nozzle 106 includes an upper nozzle component 102 and a lower nozzle component 103 which are arranged vertically, and an air inlet 101 located in the nozzle component 102 .

[0048] The air inlet 101 is used to pass gas into the upper part 102 on the nozzle, and the upper part 102 on the nozzle is used to even the gas, so that the gas passed through the air inlet 101 is uniform. The lower part 103 on the nozzle is used to pass the uniformized gas in the upper part 102 on the nozzle into the process chamber 100. Specifically, the lower part 103 on the nozzle evenly passes the gas into the process chamber 100 through a plurality of small holes distributed therein. All of the above are conducive to making the gas that subsequently enters through the nozzle 106 more evenly distributed in the process chamber 100.

[0049] The object to be etched 104 is a semiconductor structure to be subjected to a dry etching process. As an example, Figure 3 A workpiece 104 to be etched is shown, comprising a substrate 304, a silicon pillar 303 protruding from the substrate 304, a metal layer 302 covering the silicon pillar 303, and an oxide layer 301 located on the substrate 304 and covering the metal layer 302. The oxide layer 301 is subsequently etched using a dry etching process.

[0050] In this embodiment, in the step of providing the process chamber 100 , the process chamber 100 further includes an ejector device 108 penetrating the liftable base 105 .

[0051] The ejector device 108 is used to receive the workpiece 104 to be etched after the dry etching process is completed on the workpiece 104 , so as to send the workpiece 104 to be etched out of the process chamber 100 .

[0052] In this embodiment, in the step of providing the process chamber 100 , the process chamber 100 further includes a gas extraction device 107 located on the bottom wall of the process chamber 100 .

[0053] The gas extraction device 107 is used to extract the gas in the process chamber 100 to achieve gas flow in the process chamber 100 .

[0054] As an example, in this embodiment, the air extraction device 107 includes a turbo pump.

[0055] refer to Figure 4 , adjust the distance between the liftable base 105 and the nozzle 106 to a preset process distance.

[0056] The distance between the liftable base 105 and the nozzle 106 is adjusted to a preset process distance, so that the upper surface of the etched part 104 is in a better gas flow field during the subsequent dry etching process.

[0057] In this embodiment, by adjusting the distance between the liftable base 105 and the nozzle 106, the gas flow field effect above the workpiece 104 to be etched can be adjusted after the gas is introduced into the nozzle 106. Based on the flexibility of adjusting the distance between the liftable base 105 and the nozzle 106, the optimal distance between the liftable base 105 and the nozzle 106 for obtaining the optimal gas flow field can be set for different dry etching processes as the preset process distance. Therefore, in the process chamber 100, the distance between the liftable base 105 and the nozzle 106 is adjusted to the preset process distance, so that during the etching process, the optimal gas flow field can be easily achieved above the workpiece 104 to be etched, which is beneficial to improving the etching uniformity, and further beneficial to improving the electrical properties and yield of the workpiece 104 to be etched.

[0058] In this embodiment, in the step of adjusting the distance between the liftable base 105 and the nozzle 106 to the preset process distance, the liftable base 105 is moved to the preset process position so that the distance between the liftable base 105 and the nozzle 106 is the preset process distance.

[0059] By moving the elevating base 105 to a preset process position, a better process distance is achieved between the shower head 106 and the workpiece 104 to be etched.

[0060] refer to Figure 5 Subsequently, etching gas is introduced into the process chamber 100 through the nozzle 106, and before etching the workpiece 104, the process also includes: heating the workpiece 104 to a preset process temperature.

[0061] The workpiece 104 to be etched is heated to a preset process temperature to prepare for a subsequent dry etching process.

[0062] In this embodiment, the workpiece 104 to be etched is heated to a preset process temperature by the liftable base 105 .

[0063] Correspondingly, the liftable base 105 is also used to heat the workpiece 104 to be etched.

[0064] In this embodiment, the step of heating the workpiece 104 to a preset process temperature by using the elevating pedestal 105 further includes: loading the pressure in the process chamber 100 to a preset heating pressure.

[0065] The pressure in the process chamber 100 is loaded to a preset heating pressure so that the temperature of the elevating pedestal 105 can be quickly and evenly transferred to the workpiece 104 to be etched.

[0066] Specifically, in the present embodiment, in the step of loading the pressure in the process chamber 100 to a preset heating pressure, the preset heating pressure is greater than or equal to 1.8 T, and the loading time of the preset heating pressure is greater than or equal to 120 s.

[0067] Wherein, T is the pressure unit Torr, 1T=133.322Pa.

[0068] The preset heating pressure is greater than or equal to 1.8T, and the loading time of the preset heating pressure is greater than or equal to 120s, so that the process chamber 100 has sufficient pressure and maintains sufficient heating time to efficiently heat the etched part 104 to the preset process temperature through the liftable base 105.

[0069] In this embodiment, the step of loading the pressure in the process chamber 100 to the preset heating pressure includes: introducing pressure-controlled gas into the process chamber 100 through the nozzle 106 so that the pressure in the process chamber 100 is loaded to the preset heating pressure.

[0070] The process chamber 100 is pressurized by introducing gas.

[0071] In this embodiment, in the step of introducing the pressure-controlled gas into the process chamber 100 through the showerhead 106 , the pressure-controlled gas includes a catalytic gas and an inert gas.

[0072] The catalytic gas is used for the subsequent etching reaction between the catalytic etching gas and the workpiece 104 to be etched, and the inert gas is used to remove unnecessary gases to provide a stable process environment for the subsequent dry etching process. Both the catalytic gas and the inert gas are gases used in the subsequent dry etching process. Therefore, first using the catalytic gas and the inert gas as the pressure control gas is conducive to better pressure control without causing adverse effects.

[0073] As an example, in this embodiment, the catalytic gas includes NH 3 , and the inert gas includes N 2 and Ar.

[0074] Specifically, in the present embodiment, in the step of introducing the pressure-controlled gas into the process chamber 100 through the nozzle 106 , the process flow rate of the catalytic gas is 30 sccm to 60 sccm, and the process flow rate of the inert gas is 50 sccm to 200 sccm.

[0075] In this embodiment, before the etching gas is subsequently introduced into the process chamber 100 through the nozzle 106 and the workpiece 104 is etched, the process further includes: controlling the pressure in the process chamber 100 to a preset process pressure.

[0076] The pressure in the process chamber 100 is controlled to be a preset process pressure in preparation for a subsequent dry etching process.

[0077] In this embodiment, the step of controlling the pressure in the process chamber 100 to a preset process pressure includes: introducing a pre-occupying gas into the process chamber 100 through the nozzle 106, and the process flow rate of the pre-occupying gas is equal to the preset process flow rate of the etching gas in the subsequent step of introducing the etching gas into the process chamber 100 through the nozzle 106.

[0078] A pre-occupying gas with a flow rate equal to that of the etching gas subsequently introduced into the process chamber 100 through the nozzle 106 is introduced. That is, the pre-occupying gas is first used to simulate the flow rate of the etching gas to be introduced subsequently, so as to reach the preset process pressure of the subsequent dry etching process in advance. This is beneficial to ensure that when the subsequently introduced gas is converted into the etching gas, the total gas flow (total flow) in the process chamber 100 remains consistent and makes the gas conversion more stable.

[0079] In this embodiment, in the step of introducing the pre-occupying gas into the process chamber 100 through the showerhead 106 , the pre-occupying gas includes an inert gas.

[0080] The use of inert gas for pre-occupancy is beneficial to making the process of controlling the pressure in the process chamber 100 to a preset process pressure more stable.

[0081] In this embodiment, etching gas is introduced into the process chamber 100 through the shower head 106 to etch the workpiece 104 .

[0082] Specifically, under a preset process temperature and a preset process pressure, an etching gas is introduced into the process chamber 100 through the shower head 106 , and the workpiece 104 to be etched is etched.

[0083] In this embodiment, etching gas is introduced into the process chamber 100 through the nozzle 106 , and in the step of etching the workpiece 104 , the process chamber 100 is also evacuated through the exhaust device 107 .

[0084] The process chamber 100 is evacuated by the evacuation device 107 to control the pressure.

[0085] The exhaust device 107 exhausts the process chamber 100, which affects the gas flow field above the etched workpiece 104. Therefore, the adjustment of the distance between the liftable base 105 and the nozzle 106 in this embodiment is more suitable for moving the etched workpiece 104 to the optimal position, thereby obtaining a more uniform gas flow field above the etched workpiece 104.

[0086] In this embodiment, in the step of introducing the etching gas into the process chamber 100 through the shower head 106 , the etching gas replaces the pre-occupying gas and is introduced into the process chamber 100 through the shower head 106 .

[0087] The etching gas replaces the pre-occupying gas and is introduced into the process chamber 100 through the shower head 106, so that the etching gas is introduced in a process environment maintaining a preset process pressure to perform an etching reaction.

[0088] As an example, in this embodiment, the etching gas includes HF, the gas flow rate is 500sccm-700sccm, and the oxide layer 301 is etched under the action of the catalytic gas. In this step, the process pressure is 1T-2T, and the process time is 5s-15s.

[0089] In this embodiment, after the etching gas is introduced into the process chamber 100 through the nozzle 106 and the workpiece 104 is etched, the dry etching method further includes: purifying the process chamber 100 to remove the reaction products of etching the workpiece 104.

[0090] The process chamber 100 is purified to remove the reaction products of etching the workpiece 104 to avoid affecting subsequent etching.

[0091] In this embodiment, the steps of purifying the process chamber 100 include: controlling the pressure in the process chamber 100 to 0T; and introducing a purge gas into the process chamber 100 through the nozzle 106 to purge the interior of the process chamber 100.

[0092] Specifically, in the present embodiment, in the step of introducing the purge gas into the process chamber 100 through the showerhead 106 , the purge gas includes an inert gas.

[0093] Using inert gas to clean the interior of the process chamber 100 is beneficial to reducing the impact on the workpiece 104 to be etched.

[0094] refer to Figure 6 After the etching gas is introduced into the process chamber 100 through the nozzle 106 and the workpiece 104 to be etched is etched, the process further includes: lowering the liftable base 105 to below the top of the ejector device 108 to transfer the workpiece 104 to be etched onto the ejector device 108 .

[0095] It should be noted that the movable range d of the aforementioned liftable base 105 in the longitudinal direction is the process moving distance. Within the movable range d, the liftable base 105 can carry the workpiece 104 to be etched for process operation. After etching the workpiece 104, the liftable base 105 is lowered to below the top of the ejector device 108, which is the mechanical moving distance of the liftable base 105 outside the process moving distance. That is, after the liftable base 105 is lowered to a distance d2 from the nozzle 106, it can still be mechanically moved and continue to descend to transfer the workpiece 104 to be etched to the ejector device 108.

[0096] The liftable pedestal 105 is lowered to below the top of the ejector device 108 to transfer the workpiece 104 to be etched onto the ejector device 108 in preparation for moving the workpiece 104 out of the process chamber 100 .

[0097] As an example, Figure 7 The etched part 104 after the dry etching process is shown, the oxide layer 301 is uniformly etched, and the top surface flatness is high. Figure 8 The etched part 104 is shown after a dry etching process and then a wet etching process. Since the top surface flatness of the oxide layer 301 is relatively high, the height consistency of the metal layer 302 after the wet etching is relatively good.

[0098] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A dry etching method, characterized in that: include: Providing a process chamber, including a liftable base and a showerhead located above the liftable base, wherein the liftable base carries a workpiece to be etched; Adjusting the distance between the liftable base and the nozzle to a preset process distance; The etching gas is introduced into the process chamber through the nozzle, and the workpiece to be etched is etched.

2. The dry etching method according to claim 1, characterized in that: In the step of providing the process chamber, the liftable base is movable in a longitudinal direction; In the step of adjusting the distance between the liftable base and the nozzle to a preset process distance, the liftable base is moved to a preset process position so that the distance between the liftable base and the nozzle is the preset process distance.

3. The dry etching method according to claim 2, characterized in that: In the step of providing the process chamber, the liftable base is movable in a longitudinal direction so that an adjustable distance between the liftable base and the nozzle is 20 mm to 50 mm.

4. The dry etching method according to claim 2, wherein: In the step of providing the process chamber, the process chamber further comprises an ejector device penetrating the liftable base; After the etching gas is introduced into the process chamber through the nozzle and the workpiece to be etched is etched, the method further includes: lowering the liftable base to below the top of the ejector device to transfer the workpiece to be etched onto the ejector device.

5. The dry etching method according to claim 1, wherein: In the step of providing the process chamber, the process chamber further comprises an exhaust device located on the bottom wall of the process chamber; In the step of introducing etching gas into the process chamber through the nozzle and etching the workpiece to be etched, the process chamber is also evacuated through the exhaust device.

6. The dry etching method according to claim 1, wherein: Before the etching gas is introduced into the process chamber through the nozzle and the workpiece to be etched is etched, the process further includes: heating the workpiece to be etched to a preset process temperature; The pressure in the process chamber is controlled to be a preset process pressure.

7. The dry etching method according to claim 6, characterized in that: The workpiece to be etched is heated to a preset process temperature through a liftable base.

8. The dry etching method according to claim 7, characterized in that: The step of heating the workpiece to be etched to a preset process temperature by means of a liftable pedestal further includes: loading the pressure in the process chamber to a preset heating pressure.

9. The dry etching method according to claim 8, characterized in that: In the step of loading the pressure in the process chamber to a preset heating pressure, the preset heating pressure is greater than or equal to 1.8T, and the loading time of the preset heating pressure is greater than or equal to 120s.

10. The dry etching method according to claim 8, characterized in that: The step of loading the pressure in the process chamber to a preset heating pressure includes: introducing a pressure-controlled gas into the process chamber through the nozzle, so that the pressure in the process chamber is loaded to the preset heating pressure.

11. The dry etching method according to claim 10, characterized in that: In the step of introducing the pressure-controlled gas into the process chamber through the nozzle, the pressure-controlled gas includes a catalytic gas and an inert gas.

12. The dry etching method according to claim 11, characterized in that: In the step of introducing the pressure-controlled gas into the process chamber through the nozzle, the process flow rate of the catalytic gas is 30 sccm to 60 sccm, and the process flow rate of the inert gas is 50 sccm to 200 sccm.

13. The dry etching method according to claim 6, characterized in that: The step of controlling the pressure in the process chamber to a preset process pressure includes: introducing a pre-occupying gas into the process chamber through the nozzle, the process flow rate of the pre-occupying gas being equal to the preset process flow rate of the etching gas in the step of introducing the etching gas into the process chamber through the nozzle.

14. The dry etching method according to claim 13, wherein: In the step of introducing a pre-occupying gas into the process chamber through the shower head, the pre-occupying gas includes an inert gas.

15. The dry etching method according to claim 13, wherein: In the step of introducing the etching gas into the process chamber through the nozzle, the etching gas replaces the pre-occupying gas and is introduced into the process chamber through the nozzle.

16. The dry etching method according to claim 1, wherein: After the etching gas is introduced into the process chamber through the nozzle and the workpiece to be etched is etched, the dry etching method further comprises: purifying the process chamber to remove reaction products of etching the workpiece to be etched.

17. The dry etching method according to claim 16, wherein: The step of purifying the process chamber includes: controlling the pressure in the process chamber to 0T; A purge gas is introduced into the process chamber through the shower head to purge the interior of the process chamber.

18. The dry etching method according to claim 17, wherein: In the step of introducing a purge gas into the process chamber through the showerhead, the purge gas includes an inert gas.

Images