Semiconductor film forming method
By adjusting the workbench height and argon flow rate to control the argon concentration, the ignition failure problem of the domestic HMS machine in preparing the liner barrier layer was solved, and the stability and cost-effectiveness of the film forming process were achieved.
Patent Information
- Application Number
- CN202510972217.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-14
- Publication Date
- 2025-09-19
AI Technical Summary
In the process of using domestic HMS equipment to prepare the liner barrier layer using the physical vapor deposition process, ignition failure is prone to occur, resulting in abnormal film formation process and affecting the film quality.
By adjusting the workbench height and argon flow rate, the argon concentration is controlled. First, high-flow argon is introduced at a high height and the valve is kept half-open to perform ignition pre-operation. Then, the height is lowered and high-flow argon is continued to be introduced to ensure that the argon ion concentration near the metal target is sufficient. Finally, the valve is switched to a fully open state for deposition.
It effectively avoids ignition failure, ensures the smooth progress of the film forming process, reduces production costs and maintains stable film quality, and significantly reduces the ignition failure rate.
Smart Images
Figure CN120666306A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a semiconductor film forming method. Background Art
[0002] In the semiconductor manufacturing process, the stacked titanium layer + titanium nitride layer is mainly used as the hard mask layer in the metal copper wire preparation process, or as the pad barrier layer (adhesion layer) in the metal aluminum wire preparation process. The above two applications have different requirements for film quality and the process parameter settings are different.
[0003] To expand the capabilities of these tools, the liner barrier layer is currently being prepared using the film-forming chamber of a domestic HMS (Hard Mask) machine. The titanium and titanium nitride film-forming process for this domestic HMS machine is generally as follows: First, the wafer is heated and degassed in a baking chamber (Degas chamber). Then, it is transferred to the film-forming chamber where the titanium and titanium nitride layers are deposited using physical vapor deposition. The wafer is then cooled and finally transferred out of the transfer chamber.
[0004] However, ignition (IGN) failure often occurs when using domestic HMS equipment to prepare the liner barrier layer using the physical vapor deposition process. The main manifestation of ignition failure is: insufficient argon concentration leads to abnormal power output, triggering a DC (direct current) alarm fault, thereby affecting the normal film formation process of the liner barrier layer. Summary of the Invention
[0005] The present application provides a semiconductor film forming method that can solve the problem that ignition failure is prone to occur during the current process of using domestic HMS equipment to prepare a liner barrier layer using a physical vapor deposition process, thereby affecting the normal progress of the film forming process of the liner barrier layer.
[0006] The present invention provides a semiconductor film forming method, comprising:
[0007] The first step is to provide a semiconductor structure on which a metal auxiliary layer is to be deposited, and place the semiconductor structure on a workbench at the bottom of a film-forming process chamber, wherein a metal target is provided at the top of the film-forming process chamber;
[0008] Step 2: adjusting the workbench to a first height, and introducing a first flow rate of argon gas into the film forming process chamber, while setting the valve for evacuating the film forming process chamber to a half-open state;
[0009] Step 3: performing a pre-ignition operation, lowering the workbench from the first height to a second height, and introducing a first flow rate of argon gas into the film forming process chamber, while the valve for evacuating the film forming process chamber is still set to a half-open state;
[0010] Step 4: Maintaining the height of the workbench at the second height, and introducing a second flow rate of argon gas into the film forming process chamber, while still setting the valve for evacuating the film forming process chamber to a half-open state, performing an ignition operation to ionize the argon gas in the film forming process chamber into argon ions, and bombarding the metal target with the argon ions, wherein the second flow rate is less than the first flow rate;
[0011] Step 5: Maintain the height of the workbench at the second height, and introduce a second flow rate of argon into the film-forming process chamber. At the same time, switch the opening state of the valve for vacuuming the film-forming process chamber from a half-open state to a fully open state. At this time, a physical deposition process is performed, and the metal atoms bombarded from the metal target material are deposited on the surface of the semiconductor structure to form the metal auxiliary layer.
[0012] Optionally, in the semiconductor film forming method, the operation time of the second step is 10s to 15s.
[0013] Optionally, in the semiconductor film forming method, the operation time of the third step is 2s to 5s.
[0014] Optionally, in the semiconductor film forming method, the operation time of the fourth step is 1s.
[0015] Optionally, in the semiconductor film forming method, the first flow rate ranges from 20 sccm to 22 sccm.
[0016] Optionally, in the semiconductor film forming method, the second flow rate ranges from 14 sccm to 16 sccm.
[0017] Optionally, in the semiconductor film forming method, the metal auxiliary layer is a stacked titanium layer and a titanium nitride layer, the titanium layer covers the semiconductor structure, and the titanium nitride layer covers the titanium nitride layer.
[0018] Optionally, in the semiconductor film forming method, before the first step, the semiconductor film forming method further includes: placing the semiconductor structure in a baking process chamber, and performing a heating and baking treatment on the semiconductor structure.
[0019] Optionally, in the semiconductor film forming method, after forming the metal auxiliary layer, the semiconductor film forming method further includes: performing a temperature reduction treatment on the semiconductor structure after forming the metal auxiliary layer.
[0020] The technical solution of this application has at least the following advantages:
[0021] In the present application, in the second step before the ignition operation (the fourth step), the workbench is first adjusted to the first height, and the first flow rate of argon is introduced into the film forming process chamber. At the same time, the vacuum valve is set to a half-open state. The present application adjusts the workbench to a higher first height, which can shorten the distance between the metal target and the workbench, and at the same time controls a lower vacuum speed and introduces a higher flow rate of argon (the argon flow rate in this second step is higher than the argon flow rate in the fourth and fifth steps), thereby ensuring a higher argon concentration in a smaller space near the metal target. Then, the ignition pre-operation (the third step) is performed, and the workbench is lowered from the first height to the second height. , and introduce the first flow rate of argon into the film forming process chamber. At the same time, keep the vacuum valve half-open. It can be seen that in the ignition pre-operation of the third step, continue to control the lower vacuum speed and introduce a higher flow rate of argon (the argon flow rate in this third step is higher than the argon flow rate in the fourth and fifth steps), and lower the workbench to the height of the subsequent film deposition. This further increases the concentration of argon atoms near the metal target, thereby ensuring that sufficient argon ions can be generated near the metal target during the ignition operation, thereby ensuring the normal progress of the ignition operation without increasing production costs and ensuring the stability of the film quality, thereby ensuring the smooth progress of the film formation process of the metal auxiliary layer. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0023] Figure 1 is a flow chart of a semiconductor film forming method according to an embodiment of the present invention;
[0024] Figure 2 Schematic diagram of a semiconductor structure to be deposited with a metal auxiliary layer according to an embodiment of the present invention being placed on a workbench at a first height at the bottom of a film-forming process chamber;
[0025] Figure 3 2 is a schematic diagram of a semiconductor structure to be deposited with a metal auxiliary layer according to an embodiment of the present invention being placed on a workbench at a second height at the bottom of a film forming process chamber;
[0026] Figure 4 This is a schematic diagram comparing the ignition failure rates of the traditional film forming process and the film forming method provided by this application;
[0027] The description of the accompanying drawings is as follows:
[0028] 10-film forming process chamber, 11-workbench, 12-metal target, 20-semiconductor structure on which a metal auxiliary layer is to be deposited. DETAILED DESCRIPTION
[0029] The following is a clear and complete description of the technical solutions in this application in conjunction with the accompanying drawings. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.
[0030] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0031] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal connections between two components; they can refer to wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.
[0032] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.
[0033] The inventors discovered that when the argon molecules per unit volume in the film-forming process chamber are low and the argon flow rate is insufficient, ionization fails to produce a sufficient concentration of argon ions. This causes the DC power supply output of the DC magnetron device to be too low, triggering an alarm and causing ignition (IGN) failure. Current measures to increase the argon molecule concentration per unit volume in the film-forming process chamber typically involve increasing the argon concentration or flow rate for a sufficient period of time (usually greater than 1 minute) during the ventilation phase before ignition to promote argon ion generation and thus improve ignition failure. However, this approach can extend production time and increase production costs.
[0034] Based on the above problems, the present invention provides a semiconductor film forming method. Figure 1 , Figure 1 1 is a flow chart of a semiconductor film forming method according to an embodiment of the present invention, wherein the semiconductor film forming method comprises:
[0035] First, perform the first step S1: refer to Figure 2 , Figure 2 This is a schematic diagram of an embodiment of the present invention in which a semiconductor structure to be deposited with a metal auxiliary layer is placed on a workbench at a first height at the bottom of a film-forming process chamber. A semiconductor structure 20 to be deposited with a metal auxiliary layer is provided, and the semiconductor structure 20 is placed on a workbench 11 at the bottom of a film-forming process chamber 10, wherein a metal target material 12 is provided at the top of the film-forming process chamber 10.
[0036] Among them, there are also provided near the film forming process chamber 10 a gas supply device (not shown) for ventilating the film forming process chamber 10 (for example, argon), a DC magnetron device (not shown) electrically connected to the metal target material 12, and an exhaust device (not shown) for vacuuming the film forming process chamber 10, wherein a vacuum valve is provided on the exhaust device.
[0037] Furthermore, before the first step S1 , the semiconductor film forming method may further include: placing the semiconductor structure 20 into a baking process chamber, and performing a heating and baking treatment on the semiconductor structure 20 to remove residual gas on the surface of the semiconductor structure 20 .
[0038] Then, a second step S2 is performed: the workbench 11 is adjusted to a first height d1, and a first flow rate of argon gas is introduced into the film forming process chamber 10. Simultaneously, the valve for evacuating the film forming process chamber 10 is set to a half-open state. Setting the vacuum valve to a half-open state can control the chamber pressure to decrease more slowly than when the valve is fully open, thereby increasing the argon concentration per unit volume of the space between the metal target 12 and the workbench 11.
[0039] Preferably, the operation time of the second step is 10s to 15s.
[0040] Preferably, the first flow rate ranges from 20 sccm to 22 sccm.
[0041] In the second step, the workbench is first adjusted to a first height d1, and a first flow rate of argon is introduced into the film forming process chamber. At the same time, the vacuum valve is set to a half-open state. The present application adjusts the workbench to a higher first height, which can shorten the distance d2 between the metal target and the workbench. At the same time, a lower vacuum speed is controlled and a higher flow rate of argon is introduced (the argon flow rate in this second step is higher than the argon flow rate in the fourth and fifth steps), thereby ensuring a higher argon concentration in a smaller space near the metal target.
[0042] Next, perform the third step S3: refer to Figure 3 , Figure 3 This is a schematic diagram of an embodiment of the present invention in which a semiconductor structure to be deposited with a metal auxiliary layer is placed on a workbench at a second height at the bottom of a film-forming process chamber, and an ignition pre-operation is performed to lower the workbench 11 from the first height d1 to the second height d3, and introduce a first flow rate of argon gas into the film-forming process chamber 10. At the same time, the opening state of the valve for vacuuming the film-forming process chamber 10 is still set to a half-open state.
[0043] Preferably, the operation time of the third step is 2s to 5s.
[0044] During the ignition pre-operation (the third step), the workbench is lowered from the first height d1 to the second height d3, and the first flow rate of argon is introduced into the film forming process chamber. At the same time, the vacuum valve is kept half-open. It can be seen that in the ignition pre-operation of the third step, the lower vacuum speed is continued to be controlled and a higher flow rate of argon is introduced (the argon flow rate in this third step is higher than the argon flow rate in the fourth and fifth steps), and the workbench is lowered to the height of subsequent film deposition (at this time, the distance between the metal target and the workbench is d4). This further increases the concentration of argon atoms near the metal target, thereby ensuring that sufficient argon ions can be generated near the metal target during the ignition operation, thereby ensuring the normal progress of the ignition operation without increasing production costs and ensuring the stability of the film quality, thereby ensuring the smooth progress of the film forming process of the metal auxiliary layer, saving process time and manufacturing costs.
[0045] Further, the fourth step S4 is performed: the height of the workbench 11 is maintained at the second height d3, and a second flow rate of argon gas is introduced into the film forming process chamber 10. At the same time, the opening state of the valve for vacuuming the film forming process chamber 10 is still set to a half-open state. At this time, an ignition operation is performed to ionize the argon gas in the film forming process chamber 10 into argon ions, and the argon ions bombard the metal target material 12, wherein the second flow rate is less than the first flow rate.
[0046] Specifically, in the fourth step S4, at this time, the argon concentration near the metal target material 12 meets the argon molecule concentration required for the ignition operation, and the DC magnetron device is used to discharge the argon gas in the film forming process chamber 10, so that the argon gas is ionized into argon ions. The argon ions bombard the metal target material 12, and the metal atoms in the metal target material 12 are bombarded out.
[0047] Preferably, the second flow rate ranges from 14 sccm to 16 sccm.
[0048] In this embodiment, the operation duration of the fourth step is 1 second.
[0049] Finally, execute the fifth step S5: maintain the height of the workbench 11 at the second height d3, and introduce a second flow rate of argon into the film forming process chamber 10. At the same time, switch the opening state of the valve for vacuuming the film forming process chamber 10 from a half-open state to a fully open state. At this time, a physical deposition process is performed, and the metal atoms bombarded from the metal target material 12 are deposited on the surface of the semiconductor structure 20 to form the metal auxiliary layer (not shown).
[0050] In this embodiment, the metal auxiliary layer is a stacked titanium layer and a titanium nitride layer, the titanium layer covers the semiconductor structure, and the titanium nitride layer covers the titanium nitride layer.
[0051] Wherein, the metal target 12 is a titanium metal target.
[0052] During the deposition of the titanium nitride layer, a gas containing nitrogen ions needs to be introduced into the film forming process chamber 10 .
[0053] Furthermore, after forming the metal auxiliary layer, the semiconductor film forming method may further include: cooling the semiconductor structure after the metal auxiliary layer is formed. Subsequently, the semiconductor structure after the metal auxiliary layer is removed from the film forming process chamber 10 and transferred to a transfer chamber for the next process.
[0054] refer to Figure 4 , Figure 4 This is a comparison diagram of the ignition failure rate of the traditional film forming process and the film forming method provided by this application. On the film forming process chamber of the domestic HMS model, the traditional film forming process and the semiconductor film forming method provided by this application were used to verify the Liner process L01 (Ti250TiN250) process, which refers to the verification of the 250 angstrom titanium layer + 250 angstrom titanium nitride layer film forming process. The traditional process and the film forming method of this application were both verified using 75pcs wafers. The verification results are shown as follows: Figure 4As shown, when a stack of titanium and titanium nitride layers was prepared using a traditional film-forming process, 6 out of 75 wafers experienced abnormal power output DC (direct current) alarm failures, with an ignition failure rate as high as 8%. However, when a stack of titanium and titanium nitride layers was prepared using the semiconductor film-forming method provided in this application, none of the 75 wafers experienced abnormal power output DC (direct current) alarms. This shows that the semiconductor film-forming method provided in this application can significantly improve the ignition failure rate when preparing a liner barrier layer. In addition, the resistance and film thickness tests of the stack of titanium and titanium nitride layers on the 75 wafers prepared using the film-forming method provided in this application showed no abnormalities.
[0055] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of this application.
Claims
1. A semiconductor film forming method, characterized in that: include: The first step is to provide a semiconductor structure on which a metal auxiliary layer is to be deposited, and place the semiconductor structure on a workbench at the bottom of a film-forming process chamber, wherein a metal target is provided at the top of the film-forming process chamber; Step 2: adjusting the workbench to a first height, and introducing a first flow rate of argon gas into the film forming process chamber, while setting the valve for evacuating the film forming process chamber to a half-open state; Step 3: performing a pre-ignition operation, lowering the workbench from the first height to a second height, and introducing a first flow rate of argon gas into the film forming process chamber, while the valve for evacuating the film forming process chamber is still set to a half-open state; Step 4: Maintaining the height of the workbench at the second height, and introducing a second flow rate of argon gas into the film forming process chamber, while still setting the valve for evacuating the film forming process chamber to a half-open state, performing an ignition operation to ionize the argon gas in the film forming process chamber into argon ions, and bombarding the metal target with the argon ions, wherein the second flow rate is less than the first flow rate; Step 5: Maintain the height of the workbench at the second height, and introduce a second flow rate of argon into the film-forming process chamber. At the same time, switch the opening state of the valve for vacuuming the film-forming process chamber from a half-open state to a fully open state. At this time, a physical deposition process is performed, and the metal atoms bombarded from the metal target material are deposited on the surface of the semiconductor structure to form the metal auxiliary layer.
2. The semiconductor film forming method according to claim 1, wherein The operation time of the second step is 10s to 15s.
3. The semiconductor film forming method according to claim 1, wherein: The operation time of the third step is 2s to 5s.
4. The semiconductor film forming method according to claim 1, wherein: The operation duration of the fourth step is 1 second.
5. The semiconductor film forming method according to claim 1, wherein The first flow rate ranges from 20 sccm to 22 sccm.
6. The semiconductor film forming method according to claim 1, wherein: The second flow rate ranges from 14 sccm to 16 sccm.
7. The semiconductor film forming method according to claim 1, wherein: The metal auxiliary layer is a stacked titanium layer and a titanium nitride layer, the titanium layer covers the semiconductor structure, and the titanium nitride layer covers the titanium nitride layer.
8. The semiconductor film forming method according to claim 1, wherein: Before the first step, the semiconductor film forming method further includes: placing the semiconductor structure in a baking process chamber and performing a heating and baking treatment on the semiconductor structure.
9. The semiconductor film forming method according to claim 1, wherein: After forming the metal auxiliary layer, the semiconductor film forming method further includes: performing a temperature reduction process on the semiconductor structure after forming the metal auxiliary layer.