Gate metal filling method

Abstract

The invention discloses a gate metal filling method, which is applied to the field of semiconductor preparation, and comprises the following steps: in a device of which a gate metal filling region is filled with pseudo polycrystalline silicon, etching pseudo polycrystalline silicon with a preset height and a side wall with a preset height until the pseudo polycrystalline silicon and the side wall are flush to serve as a device of gate metal to be formed; a to-be-etched film layer is prepared on the surface, provided with the gate metal filling area, of the to-be-formed gate metal device, etching is carried out, so that a film layer slope is formed, and the to-be-formed gate metal device serves as a formed gate metal device; removing the residual pseudo polycrystalline silicon in the device with the formed gate metal to form a funnel-shaped gate metal filling area; and sequentially filling the funnel-shaped gate metal filling area with a gate metal medium and gate metal to complete the filling of the gate metal. According to the invention, the gate metal filling region is set to be the funnel-shaped gate metal filling region, so that the gate metal filling uniformity is improved under the condition that the gate metal resistance is maintained, the gate metal is prevented from being lost, and the yield of the gate metal is improved.

Description

Technical Field

[0001] The invention relates to the field of semiconductor preparation, and in particular to a gate metal filling method. Background Art

[0002] When a high-dielectric gate metal is prepared using the existing Gate Last process, the line width of the gate metal filling area is small and the height of the filling area needs to be maintained, which leads to poor filling when filling the aluminum metal. This in turn leads to the loss of aluminum metal in the gate metal filling area during chemical mechanical polishing, and even aluminum metal is brought out during polishing to cause scratches, thereby affecting the yield of the manufactured device. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a gate metal filling method, which solves the problem in the prior art that aluminum metal is missing in the gate metal filling area, and even aluminum metal is brought out during grinding to cause scratches, thereby affecting the yield of the manufactured device.

[0004] In order to solve the above technical problems, the present invention provides a gate metal filling method, comprising:

[0005] In a device in which a gate metal filling region is filled with pseudo polysilicon, the pseudo polysilicon of a preset height and the sidewall of a preset height are etched to be flush, so that the height of the remaining pseudo polysilicon and the remaining sidewall is less than the height of the gate metal filling region, as a device for forming gate metal; the sidewall is formed on the side of the pseudo polysilicon in the gate metal filling region;

[0006] Preparing a film layer to be etched on a surface of the device having the gate metal to be formed and having the gate metal filling region opened therein;

[0007] Etching the film layer to be etched to form a film layer slope at the height difference step formed between the substrate provided with the gate metal filling area and the remaining sidewalls, as a device with formed gate metal;

[0008] Removing the remaining pseudo polysilicon in the device having formed gate metal to form a funnel-shaped gate metal filling region in the device having formed gate metal;

[0009] The gate metal dielectric and the gate metal are sequentially filled in the funnel-shaped gate metal filling region to complete the filling of the gate metal.

[0010] Optionally, etching the film layer to be etched to form a film layer slope at a height difference step formed between the substrate provided with the gate metal filling area and the remaining sidewalls as a device with formed gate metal, including:

[0011] The film layer to be etched is etched without a mask to form the film layer slope as the device of the formed gate metal.

[0012] Optionally, etching the film layer to be etched to form a film layer slope at a height difference step formed between the substrate provided with the gate metal filling area and the remaining sidewalls as a device with formed gate metal, including:

[0013] The film layer to be etched is etched until the remaining pseudo polysilicon is exposed, and the film layer slope is formed to serve as the device of the formed gate metal.

[0014] Optionally, etching the film layer to be etched until the remaining pseudo polysilicon is exposed and forming the film layer slope as the device of the formed gate metal includes:

[0015] The film layer to be etched is etched until all the remaining pseudo polysilicon is just exposed, and the film layer slope is formed to serve as the device of the formed gate metal.

[0016] Optionally, etching the film layer to be etched until the remaining pseudo polysilicon is exposed and forming the film layer slope as the device of the formed gate metal includes:

[0017] The film layer to be etched is etched until the remaining pseudo polysilicon is exposed, and a film layer slope is formed with the top at the same height as the substrate, as the device of the formed gate metal.

[0018] Optionally, in the device in which the gate metal filling region is filled with pseudo polysilicon, the pseudo polysilicon of a preset height and the sidewall of a preset height are etched to be flush, so that the height of the remaining pseudo polysilicon and the remaining sidewall is less than the height of the gate metal filling region, as a device for forming gate metal, comprising:

[0019] In the device in which the gate metal filling region is filled with the pseudo polysilicon, etching the sidewalls of a preset height so that the height of the remaining sidewalls is smaller than the height of the gate metal filling region as a device to be etched;

[0020] The pseudo polysilicon in the device to be etched is etched to make the remaining pseudo polysilicon flush with the remaining sidewalls, so as to serve as the device for the gate metal to be formed.

[0021] Optionally, in the device in which the pseudo polysilicon is filled in the gate metal filling region, the sidewalls of a preset height are etched so that the height of the remaining sidewalls is less than the height of the gate metal filling region, as the device to be etched, including:

[0022] In the device in which the gate metal filling region is filled with the pseudo polysilicon, the sidewalls of a preset height are etched by dry etching so that the height of the remaining sidewalls is smaller than the height of the gate metal filling region, as the device to be etched;

[0023] Correspondingly, the dummy polysilicon in the device to be etched is etched so that the remaining dummy polysilicon is flush with the remaining sidewalls, and the device to be formed as the gate metal includes:

[0024] The pseudo polysilicon in the device to be etched is dry-etched to make the remaining pseudo polysilicon flush with the remaining sidewalls, thereby forming the device for the gate metal to be formed.

[0025] Optionally, the step of preparing a film layer to be etched on a surface of the device having the gate metal to be formed and having the gate metal filling region opened therein comprises:

[0026] A silicon nitride substrate is deposited on the surface of the device with the gate metal to be formed, where the gate metal filling region is opened, to form a silicon nitride film layer to be etched.

[0027] Optionally, in the device in which the pseudo polysilicon is filled in the gate metal filling region, the sidewalls of a preset height are etched so that the height of the remaining sidewalls is less than the height of the gate metal filling region, as the device to be etched, including:

[0028] In the device in which the gate metal filling region is filled with the pseudo polysilicon, a photoresist material is prepared on the entire surface of the gate metal filling region;

[0029] Removing the photoresist material on the upper side of the gate metal filling region, etching the sidewalls of a preset height so that the height of the remaining sidewalls is smaller than the height of the gate metal filling region, as the device to be etched;

[0030] Correspondingly, the dummy polysilicon in the device to be etched is etched so that the remaining dummy polysilicon is flush with the remaining sidewalls, and the device to be formed as the gate metal includes:

[0031] The pseudo polysilicon in the device to be etched is etched to make the remaining pseudo polysilicon flush with the remaining sidewalls, and the remaining photoresist material is removed to form the device with the gate metal to be formed.

[0032] Optionally, after the gate metal filling is completed, the gate metal dielectric and the gate metal are sequentially filled in the funnel-shaped gate metal filling region, and the method further includes:

[0033] The surface on which the gate metal filling is completed is subjected to chemical mechanical polishing to planarize the surface on which the gate metal filling is completed.

[0034] It can be seen that the gate metal filling method provided by the present invention includes etching pseudo-polysilicon of a preset height and a side wall of a preset height until they are flush in a device in which pseudo-polysilicon is filled in a gate metal filling area, so that the heights of the remaining pseudo-polysilicon and the remaining side wall are less than the height of the gate metal filling area; as a device for forming gate metal, the side wall is formed on the side of the pseudo-polysilicon in the gate metal filling area; a film layer to be etched is prepared on the surface of the device in which the gate metal is formed and the gate metal filling area is opened; the film layer to be etched is etched to form a film layer slope at the height difference step formed between the substrate provided with the gate metal filling area and the remaining side wall; as a device in which the gate metal has been formed, the remaining pseudo-polysilicon in the device in which the gate metal has been formed is removed to form a funnel-shaped gate metal filling area in the device in which the gate metal has been formed; the gate metal medium and the gate metal are filled in the funnel-shaped gate metal filling area in turn to complete the filling of the gate metal. The present invention improves the efficiency of filling the gate metal and the uniformity of the filled gate metal, avoids the occurrence of gate metal missing, and is compatible with the existing technology, thereby improving the yield of the gate metal, without changing the width of the gate metal after forming and maintaining the resistance of the gate metal, by setting the gate metal filling area as a funnel-shaped gate metal filling area. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0036] Figure 1 A flow chart of a gate metal filling method provided by an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of a process of a gate metal filling method provided by an embodiment of the present invention;

[0038] Figure 3 A flow chart of filling a titanium nitride dielectric in a funnel-shaped gate metal filling region corresponding to an N-type gate provided by an embodiment of the present invention;

[0039] Figure 4 A flow chart of another gate metal filling method provided by an embodiment of the present invention;

[0040] Figure 5A schematic structural diagram of a formed gate metal device with a film layer slope provided by an embodiment of the present invention;

[0041] Figure 6 A flow chart of another gate metal filling method provided by an embodiment of the present invention;

[0042] Figure 7 A flow chart of another gate metal filling method provided by an embodiment of the present invention;

[0043] Figure 2 and Figure 5 In the figure, the reference numerals are described as follows:

[0044] 11-pseudo polysilicon, 12-remaining pseudo polysilicon;

[0045] 21-side wall, 22-remaining side wall;

[0046] 31-film layer to be etched, 32-film layer slope;

[0047] 41-Gate metal dielectric and gate metal. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] When a high dielectric gate metal is prepared using the existing Gate Last process, the line width of the gate metal filling area is small and the height of the filling area needs to be maintained to ensure the gate resistance value. When filling the metal into the trench, it is easy to cause poor filling problems. Some areas have missing filled metal, resulting in poor contact of the device. Furthermore, due to the unevenness of the filled metal, it is easy to bring out the metal during chemical mechanical polishing to cause scratches, thereby affecting the yield of the manufactured device.

[0050] The present invention improves the efficiency of filling the gate metal and the uniformity of the filled gate metal, avoids the occurrence of gate metal missing, and is compatible with the existing technology, thereby improving the yield of the gate metal, without changing the width of the gate metal after forming and maintaining the resistance of the gate metal, by setting the gate metal filling area as a funnel-shaped gate metal filling area.

[0051] Embodiment 1:

[0052] This embodiment can refer to Figure 1 and Figure 2 , Figure 1 A flow chart of a gate metal filling method provided by an embodiment of the present invention, Figure 2 A schematic flow chart of a gate metal filling method provided in an embodiment of the present invention.

[0053] Please refer to Figure 1 , the method may include:

[0054] S101: In a device in which pseudo-polysilicon is filled in a gate metal filling area, the pseudo-polysilicon of a preset height and the sidewall of a preset height are etched until they are flush, so that the heights of the remaining pseudo-polysilicon and the remaining sidewall are smaller than the height of the gate metal filling area, serving as a device for forming gate metal; the sidewall is formed on the side of the pseudo-polysilicon in the gate metal filling area.

[0055] It should be noted that in the device in the present embodiment, the pseudo polysilicon 11 is filled in the gate metal filling region, and the sidewall 21 is formed in the gate metal filling region, and the pseudo polysilicon 11 is filled beside the sidewall 21 in the gate metal filling region, that is, the formed sidewall 21 is on the side of the filled pseudo polysilicon 11, and the upper surface of the sidewall 21 and the pseudo polysilicon 11 formed in the gate metal filling region is flush with the substrate. To ensure that the upper surface of the sidewall 21 and the pseudo polysilicon 11 formed in the gate metal filling region is flush with the substrate, the upper surface of the device where the gate metal is set can be ground after the sidewall 21 is formed and the pseudo polysilicon 11 is filled. In the present embodiment, the substrate is a structure with a gate metal filling region opened on the surface, for example, the gate metal is set on the back side of the semiconductor device. At this time, the substrate is the substrate of the semiconductor device, so the specific material of the substrate can be set according to the material of the semiconductor substrate. In this embodiment, the side wall 21 can be an ONO (oxide-nitride-oxide) structure formed by deposition. When the ONO structure is deposited in this embodiment, an ONO structure layer will be formed at the bottom of the gate metal filling area. In this embodiment, the side wall 21 only refers to the ONO structure located on the side of the pseudo polysilicon 11, as the side wall 21.

[0056] In this embodiment, the pseudo polysilicon 11 of a preset height and the sidewall 21 of a preset height are etched until they are flush, wherein this embodiment does not limit the specific setting value of the preset height, and can be set according to actual working conditions. It should be noted that the area of ​​the preset height etched needs to be removed eventually, and the gate metal formed after removal needs to maintain a corresponding height to ensure the gate metal resistance, and after the preset height of etching is maintained, the surface formed by the remaining sidewall 22 and the remaining pseudo polysilicon 12 and the upper surface of the substrate form a step that can complete the subsequent etching step of forming a slope. The structure in which the height of the remaining pseudo polysilicon 12 and the remaining sidewall 22 is less than the height of the gate metal filling area is used as a device for the gate metal to be formed.

[0057] The present embodiment does not limit the specific method of etching the pseudo-polysilicon 11 of a preset height and the sidewall 21 of a preset height until they are flush, as long as the remaining sidewall 22 after etching can be flush with the upper side of the remaining polysilicon. For example, the sidewall 21 can be etched to a preset height first, and then the pseudo-polysilicon 11 can be etched to a preset height, so that the remaining sidewall 22 and the remaining pseudo-polysilicon 12 are flush, or the pseudo-polysilicon 11 can be etched to a preset height first, and then the sidewall 21 of a preset height can be etched to make the remaining sidewall 22 and the remaining pseudo-polysilicon 12 flush, or the sidewall 21 of a preset height and the pseudo-polysilicon 11 of a preset height can be etched at the same time, so that the remaining sidewall 22 and the remaining pseudo-polysilicon 12 are flush. The present embodiment also does not limit the specific etching method for etching the pseudo-polysilicon 11 and the sidewall 21. The present embodiment does not limit the specific method of forming the pseudo-polysilicon 11. For example, the pseudo polysilicon 11 may be formed by using additive manufacturing and filling with undoped silicon glass, or the pseudo polysilicon 11 may be formed by other methods.

[0058] Further, in order to reduce the complexity of the process of etching the pseudo-polysilicon of a preset height and the sidewall of a preset height to be flush, and ensure that the device can be stably formed, in the device in which the gate metal filling area is filled with pseudo-polysilicon, the pseudo-polysilicon of a preset height and the sidewall of a preset height are etched to be flush, so that the height of the remaining pseudo-polysilicon and the remaining sidewall is less than the height of the gate metal filling area, and the device as the gate metal to be formed may include the following steps:

[0059] Step S11: in the device whose gate metal filling region is filled with pseudo polysilicon, etching a sidewall with a preset height so that the height of the remaining sidewall is smaller than the height of the gate metal filling region as a device to be etched.

[0060] Step S12: etching the pseudo polysilicon in the device to be etched so that the remaining pseudo polysilicon is flush with the remaining sidewalls, thus forming a device for forming a gate metal.

[0061] In this embodiment, the sidewall 21 of a preset height is etched in advance, and then the pseudo polysilicon 11 of a preset height is etched, so that the remaining pseudo polysilicon 12 is flush with the remaining sidewall 22. In this embodiment, by etching the sidewall 21 and the pseudo polysilicon 11 in sequence, it can be ensured that the remaining pseudo polysilicon 12 and the remaining sidewall 22 remain flush after etching, and by etching the pseudo polysilicon 11 and the sidewall 21 in steps, it is compatible with the prior art and can ensure the quality of etching.

[0062] Furthermore, in order to further ensure etching stability and simplify etching steps, in the device in which pseudo polysilicon is filled in the gate metal filling region, a sidewall of a preset height is etched so that the height of the remaining sidewall is less than the height of the gate metal filling region. As the device to be etched, it may include:

[0063] In a device in which a gate metal filling region is filled with pseudo polysilicon, a sidewall of a preset height is etched by dry etching so that the height of the remaining sidewall is smaller than the height of the gate metal filling region, as a device to be etched;

[0064] Accordingly, the pseudo polysilicon in the device to be etched is etched so that the remaining pseudo polysilicon is flush with the remaining sidewalls. The device as the gate metal to be formed may include:

[0065] The pseudo polysilicon in the device to be etched is dry-etched to make the remaining pseudo polysilicon flush with the remaining sidewalls, thus forming a device for the gate metal to be formed.

[0066] It should be noted that, in the present embodiment, a dry etching method is used to etch the sidewall 21 of a preset height and the pseudo-polysilicon 11 of a preset height. The sidewall 21 can be etched by recess etching in the dry etching. After etching the sidewall 21 of a preset height, the pseudo-polysilicon 11 is recess etched by in-situ conversion, so that the surfaces of the remaining sidewall 22 and the remaining pseudo-polysilicon 12 after etching are flush, so as to serve as a device for the gate metal to be formed.

[0067] Further, in order to ensure that the etching of pseudo-polysilicon and sidewalls does not affect other areas, in the device in which pseudo-polysilicon is filled in the gate metal filling area, the sidewalls of a preset height are etched so that the height of the remaining sidewalls is less than the height of the gate metal filling area. As the device to be etched, the following steps may be included:

[0068] Step S21: in a device in which a gate metal filling region is filled with pseudo polysilicon, a photoresist material is prepared on the entire surface of the gate metal filling region.

[0069] Step S22: removing the photoresist material on the upper side of the gate metal filling region, and etching the sidewalls of a preset height so that the height of the remaining sidewalls is smaller than the height of the gate metal filling region, as a device to be etched.

[0070] Accordingly, the pseudo polysilicon in the device to be etched is etched so that the remaining pseudo polysilicon is flush with the remaining sidewalls. The device as the gate metal to be formed may include:

[0071] The pseudo polysilicon in the device to be etched is etched to make the remaining pseudo polysilicon flush with the remaining sidewalls, and the remaining photoresist material is removed to form a device for the gate metal to be formed.

[0072] It should be noted that in this embodiment, by preparing a photoresist material on the entire surface of the gate metal filling region in the device filled with pseudo polysilicon 11 in the gate metal filling region, and removing the photoresist material on the upper side of the gate metal filling region, it is possible to ensure that when etching the sidewall 21 and the pseudo polysilicon 11, the structure of other regions is not affected, thereby improving the efficiency of the etching process and the device quality rate. In addition, in this embodiment, after the pseudo polysilicon 11 and the sidewall 21 are etched, the remaining photoresist material is removed to form the device with the gate metal to be formed.

[0073] S102: preparing a film layer to be etched on a surface of a device with a gate metal to be formed and having a gate metal filling region opened therein.

[0074] It should be noted that in the present embodiment, a film layer 31 to be etched is prepared on the surface of a gate metal filling region in a device to be etched with a gate metal, that is, the film layer 31 to be etched is prepared on the upper side of the remaining sidewalls 22 and the remaining pseudo polysilicon 12. The present embodiment does not limit the specific material of the prepared film layer 31 to be etched, as long as it can be etched to form a slope and is a non-metal or non-metal oxide. The present embodiment does not limit the specific method of preparing the film layer 31 to be etched on the surface of a gate metal filling region in a device to be etched with a gate metal. For example, the film layer substrate to be etched can be directly deposited to form the film layer 31 to be etched, or the film layer 31 to be etched can be prepared by other methods. In the device to be formed with gate metal, the film layer 31 to be etched prepared in the present embodiment forms a film layer 31 to be etched of a specified height on each exposed surface with a gate metal filling area. The film layer 31 to be etched formed in the depth direction of the gate metal filling area can be defined as a side film layer 31 to be etched. The lateral width of the side film layer 31 to be etched can be the same as the lateral width of the remaining side wall 22 to facilitate the subsequent formation of a slope structure.

[0075] Further, in order to ensure that the prepared film layer to be etched can be etched to form a film layer slope, ensure the stability of the prepared film layer slope, and ensure the efficiency of the prepared film layer slope, the above-mentioned preparation of the film layer to be etched on the surface of the device with the gate metal to be formed, which has a gate metal filling area, may include:

[0076] A silicon nitride substrate is deposited on a surface of a device with a gate metal filling region to be formed, so as to form a silicon nitride film layer to be etched.

[0077] It should be noted that silicon nitride is selected in the present embodiment, and a silicon nitride film layer to be etched is prepared on the surface of a device with a gate metal filling area to be formed by deposition. The silicon nitride film layer has high mechanical strength, can ensure the stability of the structure, and is compatible with the process, and can improve the efficiency of preparing the film layer slope.

[0078] S103: etching the film layer to be etched to form a film layer slope at the height difference step formed between the substrate with the gate metal filling area and the remaining sidewalls, as a device with formed gate metal.

[0079] It should be noted that in this embodiment, by etching the film layer 31 to be etched, maskless etching can be used to form a film layer slope 32 at a step with a height difference between the substrate with a gate metal filling area and the remaining side wall 22, or other etching methods using the Spacer effect (the Spacer effect is etching to form a slope at a step) can be used to form a film layer slope 32 at a step with a height difference between the substrate with a gate metal filling area and the remaining side wall 22, as a device with formed gate metal. In this embodiment, the specific method of etching the film layer 31 to be etched is not limited, for example, etching is performed using the above-mentioned Spacer effect, or maskless etching and other etching methods that can form a slope can also be used. In addition, the present invention does not limit the bottom of the formed film layer slope 32 to the first cutoff position of the remaining pseudo-polysilicon 12 along the remaining side wall 22, as long as the film layer slope 32 can be formed. For example, the first cut-off position can be set at the contact position between the remaining sidewall 22 and the remaining pseudo-polysilicon 12, or the first cut-off position can be set at other positions. It should be noted that if the first cut-off position is set on the surface of the remaining pseudo-polysilicon 12, when the remaining pseudo-polysilicon 12 is removed later, the portion of the film layer slope 32 on the upper side of the remaining pseudo-polysilicon 12 should also be removed accordingly, that is, the bottom of the film layer slope 32 formed at this time moves upward along the second cut-off position perpendicular to the direction in which the remaining sidewall 22 and the remaining pseudo-polysilicon 12 form a flush plane. Accordingly, this embodiment does not limit the second cut-off position at the bottom of the film layer slope 32 to a specific vertical position, as long as it is not lower than the upper surface of the remaining pseudo-polysilicon 12 and can form the film layer slope 32. In this embodiment, the film layer slope 32 is a film layer slope formed obliquely downward along the contact position between the substrate and the gate metal filling area. This embodiment also does not limit the third cut-off position of the upper vertex of the film layer slope 32, as long as it is lower than the upper surface of the substrate and higher than the above-mentioned second cut-off position. The surface of the film layer slope 32 formed in this embodiment can be of any shape, as long as the cross-section of the film layer slope 32 gradually decreases in the direction pointing upward along the gate metal filling region. For example, the surface of the film layer slope 32 can be an arc surface, or the surface of the film layer slope 32 can also be a flat surface, or the surface of the film layer slope 32 can also be other structures.

[0080] Further, in order to ensure the etching efficiency, the above-mentioned etching of the film layer to be etched to form a film layer slope at the height difference step formed between the substrate with the gate metal filling area and the remaining sidewall, as a device with formed gate metal, can include the following steps:

[0081] The film layer to be etched is etched without a mask to form a film layer slope as a device with formed gate metal.

[0082] It should be noted that in this embodiment, the maskless etching method is used to etch the film layer 31 to be etched, so as to form a film layer slope 32 at a step with a height difference between the substrate provided with the gate metal filling area and the remaining side wall 22. This can simplify the steps of etching to form the film layer slope 32 and improve the efficiency of etching to form the film layer slope 32 while ensuring the preparation process.

[0083] S104: Remaining pseudo polysilicon in the device having formed gate metal is removed to form a funnel-shaped gate metal filling region in the device having formed gate metal.

[0084] In this embodiment, the remaining pseudo polysilicon 12 in the device having formed gate metal is removed to form a funnel-shaped gate metal filling region.

[0085] S105: filling the gate metal dielectric and the gate metal in the funnel-shaped gate metal filling region in sequence to complete the filling of the gate metal.

[0086] It should be noted that in this embodiment, the gate metal is filled by sequentially filling the gate metal dielectric and the gate metal 41 in the funnel-shaped gate metal filling area formed above. This embodiment is not limited to the specific material of the gate metal dielectric and the specific material of the gate metal that are sequentially filled in the funnel-shaped gate metal filling area, and can be set according to actual working conditions, but the filled gate metal should be a metal material.

[0087] Furthermore, in order to ensure the functionality of the device and avoid damage to the device, the above-mentioned sequentially filling the gate metal dielectric and the gate metal in the funnel-shaped gate metal filling area to complete the filling of the gate metal may include the following steps:

[0088] Step S31: filling a tantalum nitride dielectric in the funnel-shaped gate metal filling region, and filling a titanium nitride dielectric in the funnel-shaped gate metal filling region corresponding to the N-type gate, to obtain a first filled device.

[0089] Step S32: filling the funnel-shaped gate metal filling region in the first filling device with the remaining gate metal dielectric and gate metal in sequence to complete the filling of the gate metal.

[0090] The device in which the gate metal filling region is filled with pseudo polysilicon 11 includes a P-type gate and an N-type gate, and the P-type gate and the N-type gate are respectively provided with gate metal filling regions.

[0091] It should be noted that, in this embodiment, since the device in which the gate metal filling area is filled with pseudo polysilicon 11 includes a P-type gate and an N-type gate, in order to ensure that the device can operate stably after the gate metal is filled, when filling the titanium nitride medium, it is only necessary to retain the titanium nitride medium filled in the funnel-shaped gate metal filling area of ​​the N-type gate. This embodiment does not limit the specific method of filling the titanium nitride medium only in the funnel-shaped gate metal filling area corresponding to the N-type gate. For example, the titanium nitride medium can be filled in the funnel-shaped gate metal filling areas corresponding to the N-type gate and the P-type gate at the same time, and then the titanium nitride medium filled in the funnel-shaped gate metal filling area corresponding to the P-type gate is removed, or the funnel-shaped gate metal filling area corresponding to the P-type gate can be blocked so that the titanium nitride medium is only filled in the funnel-shaped gate metal filling area corresponding to the N-type gate.

[0092] To make the present invention easier to understand, the gate metal filling method in this embodiment can refer to Figure 2 , Figure 2 A flow chart of a gate metal filling method provided for an embodiment of the present invention. This embodiment focuses on etching a pseudo polysilicon 11 of a preset height and a sidewall 21 of a preset height to be flush in a device filled with pseudo polysilicon 11 in a gate metal filling area, so that the height of the remaining pseudo polysilicon 12 and the remaining sidewall 22 is less than the height of the gate metal filling area, as a device to be formed with gate metal; preparing a film layer 31 to be etched on the surface of the device to be formed with a gate metal filling area; etching the film layer to be etched to form a film layer slope 32 at the height difference step formed between the substrate with the gate metal filling area and the remaining sidewall 22, as a device with formed gate metal; removing the remaining pseudo polysilicon 12 in the device with formed gate metal, so as to form a funnel-shaped gate metal filling area in the device with formed gate metal; filling the funnel-shaped gate metal filling area with gate metal dielectric and gate metal 41 in turn, and completing the filling of gate metal.

[0093] Further, in order to ensure the simplicity of preparation of filling the titanium nitride dielectric in the funnel-shaped gate metal filling area corresponding to the N-type gate, the above-mentioned filling of the tantalum nitride dielectric in the funnel-shaped gate metal filling area and the titanium nitride dielectric in the funnel-shaped gate metal filling area corresponding to the N-type gate to obtain the first filling device may include the following steps. For details, please refer to Figure 3 , Figure 3 A flow chart of filling a titanium nitride dielectric in a funnel-shaped gate metal filling region corresponding to an N-type gate is provided in an embodiment of the present invention.

[0094] S201: Tantalum nitride dielectric and titanium nitride dielectric are sequentially filled in the funnel-shaped gate metal filling region.

[0095] In this embodiment, by filling tantalum nitride dielectric and titanium nitride dielectric in sequence in all funnel-shaped gate metal filling areas at the same time, the titanium nitride dielectric filled in the funnel-shaped gate metal filling area corresponding to the P-type gate can be removed later to reduce the complexity of preparation.

[0096] S202: preparing a photoresist material on the surface of the funnel-shaped gate metal filling region corresponding to the N-type gate, and etching the titanium nitride medium exposed in the funnel-shaped gate metal filling region.

[0097] In this embodiment, a photoresist material is prepared on the surface of the funnel-shaped gate metal filling region corresponding to the N-type gate, so that when the titanium nitride medium in the funnel-shaped gate metal filling region corresponding to the P-type gate is subsequently filled, the titanium nitride medium in the funnel-shaped gate metal filling region corresponding to the N-type gate is not affected. It should be noted that in this embodiment, the photoresist material is prepared on the surface of the funnel-shaped gate metal filling region corresponding to the N-type gate, and it can not only cover the funnel-shaped gate metal filling region corresponding to the N-type gate, but at least cover part of the substrate to ensure that the photoresist material is stably formed on the surface of the funnel-shaped gate metal filling region corresponding to the N-type gate, as long as it does not block the funnel-shaped gate metal filling region corresponding to the P-type gate.

[0098] S203: removing the photoresist material prepared on the surface of the funnel-shaped gate metal filling region corresponding to the N-type gate, so that the funnel-shaped gate metal filling region corresponding to the N-type gate is filled with titanium nitride dielectric, thereby obtaining a first filling device.

[0099] In this embodiment, after etching away the titanium nitride dielectric in the funnel-shaped gate metal filling area corresponding to the P-type gate, the remaining photoresist material is removed to form a first filling device in which the funnel-shaped gate metal filling area corresponding to the N-type gate is filled with the titanium nitride dielectric, while the funnel-shaped gate metal filling area corresponding to the P-type gate is not filled with the titanium nitride dielectric.

[0100] Furthermore, in order to remove the invalid area after the gate metal is filled to form a fully functional device, the gate metal dielectric and the gate metal are sequentially filled in the funnel-shaped gate metal filling area. After the gate metal is filled, the following steps may also be included:

[0101] The surface filled with the gate metal is subjected to chemical mechanical polishing to planarize the surface filled with the gate metal.

[0102] It should be noted that, in this embodiment, after the gate metal is filled, the surface is chemically mechanically polished to remove the invalid area. In this embodiment, the surface is chemically mechanically polished to the lower side of the remaining sidewall to completely remove the formed film layer slope to ensure the functionality of the device.

[0103] The gate metal filling method provided by the embodiment of the present invention includes etching pseudo polysilicon of a preset height and a side wall of a preset height until they are flush in a device in which pseudo polysilicon is filled in a gate metal filling region, so that the height of the remaining pseudo polysilicon and the remaining side wall are less than the height of the gate metal filling region; as a device for forming gate metal, the side wall is formed on the side of the pseudo polysilicon in the gate metal filling region; a film layer to be etched is prepared on the surface of the device in which the gate metal is formed and the gate metal filling region is opened; the film layer to be etched is etched to form a film layer slope at the height difference step formed between the substrate provided with the gate metal filling region and the remaining side wall; as a device in which the gate metal has been formed, the remaining pseudo polysilicon in the device in which the gate metal has been formed is removed to form a funnel-shaped gate metal filling region in the device in which the gate metal has been formed; the gate metal medium and the gate metal are sequentially filled in the funnel-shaped gate metal filling region to complete the filling of the gate metal. The present invention improves the efficiency of filling the gate metal and the uniformity of the filled gate metal, avoids the occurrence of gate metal missing, and is compatible with the existing technology, thereby improving the yield of the gate metal, without changing the width of the gate metal after forming and maintaining the resistance of the gate metal, by setting the gate metal filling area as a funnel-shaped gate metal filling area.

[0104] In addition, the embodiment of the present invention pre-etches the side wall of a preset height and then etches the pseudo-polysilicon of a preset height so that the remaining pseudo-polysilicon is flush with the remaining side wall, thereby ensuring that the remaining pseudo-polysilicon and the remaining side wall remain flush after etching. At the same time, by etching the pseudo-polysilicon and the side wall in steps, it is compatible with the prior art and can ensure the quality of etching; the dry etching method is used to etch the side wall of a preset height and the pseudo-polysilicon of a preset height, thereby further ensuring the stability of etching and simplifying the etching steps; by preparing the photoresist material on the upper surface of the substrate in the gate metal filling area in the device filled with pseudo-polysilicon in the gate metal filling area, it can be ensured that the substrate is not affected when etching the side wall and the pseudo-polysilicon, thereby improving the efficiency of the etching process and the yield of the device; by selecting silicon nitride, in the device to be formed gate metal, a silicon nitride film layer to be etched is prepared on the surface of the gate metal filling area in the device, thereby improving the yield of the device; The invention has high strength and can improve the efficiency of preparing the film slope. By using the maskless etching method, the film to be etched is etched to form a film slope at a step with a height difference between a substrate provided with a gate metal filling area and the remaining sidewall, which can simplify the steps of etching to form the film slope and improve the efficiency of etching to form the film slope while ensuring the preparation process. At the same time, tantalum nitride medium and titanium nitride medium are sequentially filled in all funnel-shaped gate metal filling areas, and a photoresist material is prepared on the surface of the funnel-shaped gate metal filling area corresponding to the N-type gate, and the titanium nitride medium exposed in the funnel-shaped gate metal filling area corresponding to the P-type gate is removed to avoid affecting the titanium nitride medium in the funnel-shaped gate metal filling area corresponding to the N-type gate, thereby ensuring the functionality of the device. By performing chemical mechanical grinding on the surface of the device after the gate metal is filled, the invalid area can be removed and the surface provided with the gate metal can be flattened to facilitate connection with other components.

[0105] Embodiment 2:

[0106] Please refer to Figure 4 , Figure 4 A flow chart of another gate metal filling method provided by an embodiment of the present invention, the method may include:

[0107] S301: In a device in which pseudo-polysilicon is filled in a gate metal filling area, the pseudo-polysilicon of a preset height and the sidewall of a preset height are etched until they are flush, so that the heights of the remaining pseudo-polysilicon and the remaining sidewall are smaller than the height of the gate metal filling area, serving as a device for forming gate metal; the sidewalls are formed on the sides of the pseudo-polysilicon in the gate metal filling area.

[0108] S302: preparing a film layer to be etched on a surface of a device with a gate metal filling region to be formed.

[0109] S303: etching the film layer to be etched until the remaining pseudo polysilicon is exposed, and forming a film layer slope as a device with formed gate metal.

[0110] It should be noted that in this embodiment, the film layer to be etched is etched until the remaining pseudo-polysilicon is exposed, that is, in the vertical direction, the pseudo-polysilicon of a preset height and the sidewall of a preset height are etched in step S301 of this embodiment until they are flush, that is, the upper surface of the remaining pseudo-polysilicon and the remaining sidewall in the vertical direction is used as a flush position, and in this embodiment, a partial area in the film layer to be etched is etched to the flush position formed by the remaining pseudo-polysilicon and the remaining sidewall to increase the height of the formed film layer slope, thereby increasing the area where the film layer slope is widened, and further improving the uniformity and filling efficiency of the gate metal filling. The film layer slope formed in this embodiment can refer to Figure 5 , Figure 5 A schematic structural diagram of a formed gate metal device with a film layer slope provided in an embodiment of the present invention.

[0111] This embodiment does not limit the cutoff position of etching the film layer to be etched, and the bottom plane of the film layer slope formed points to the direction of the remaining pseudo-polysilicon along the remaining side wall. For example, the cutoff position of the bottom of the film layer slope formed can be on the upper surface of the remaining side wall, or the cutoff position of the bottom of the film layer slope formed can also be on the upper surface of the remaining pseudo-polysilicon, that is, the film layer to be etched is etched to expose part of the remaining pseudo-polysilicon, or the film layer to be etched is etched to expose all the remaining pseudo-polysilicon and part of the remaining side wall. It should be further explained that the cutoff position of the bottom plane of the film layer slope formed in this embodiment points to the direction of the remaining pseudo-polysilicon along the remaining side wall, that is, the contour of the maximum distance between the bottom of the film layer slope and the substrate on the same side. If the cutoff position of the bottom of the film layer slope formed is on the upper surface of the remaining pseudo-polysilicon, then when etching the remaining pseudo-polysilicon, it is necessary to etch the film layer slope on the upper side of the remaining pseudo-polysilicon, and then the bottom plane of the film layer slope formed after etching the pseudo-polysilicon moves up in the vertical direction.

[0112] S304: removing the remaining pseudo polysilicon in the device having formed gate metal, so as to form a funnel-shaped gate metal filling region in the device having formed gate metal.

[0113] S305: filling the gate metal dielectric and the gate metal in the funnel-shaped gate metal filling region in sequence to complete the filling of the gate metal.

[0114] The gate metal filling method provided by the embodiment of the present invention includes etching pseudo-polysilicon of a preset height and a side wall of a preset height until they are flush in a device in which pseudo-polysilicon is filled in a gate metal filling area, so that the heights of the remaining pseudo-polysilicon and the remaining side wall are less than the height of the gate metal filling area; as a device for forming gate metal, the side wall is formed on the side of the pseudo-polysilicon in the gate metal filling area; a film layer to be etched is prepared on the surface of the gate metal filling area in the device for forming gate metal, the film layer to be etched is etched until the remaining pseudo-polysilicon is exposed, and a film layer slope is formed; as a device for forming gate metal, the remaining pseudo-polysilicon in the device for forming gate metal is removed to form a funnel-shaped gate metal filling area in the device for forming gate metal, and the gate metal medium and the gate metal are sequentially filled in the funnel-shaped gate metal filling area to complete the filling of the gate metal. The present invention improves the efficiency of filling the gate metal and the uniformity of the filled gate metal without changing the width of the gate metal after forming and maintaining the resistance of the gate metal by setting the gate metal filling area as a funnel-shaped gate metal filling area, thereby avoiding the occurrence of gate metal missing, being compatible with the existing technology, and thus improving the yield of the gate metal. By etching the film layer to be etched until the remaining pseudo-polysilicon is exposed, the height of the formed film layer slope is increased, thereby increasing the area where the film layer slope is widened, and further improving the uniformity and filling efficiency of the filled gate metal.

[0115] Embodiment 3:

[0116] Please refer to Figure 6 , Figure 6 A flow chart of another gate metal filling method provided by an embodiment of the present invention, the method may include:

[0117] S401: In a device in which a gate metal filling region is filled with pseudo-polysilicon, the pseudo-polysilicon of a preset height and the sidewall of a preset height are etched until they are flush, so that the heights of the remaining pseudo-polysilicon and the remaining sidewall are smaller than the height of the gate metal filling region, serving as a device for forming gate metal; the sidewall is formed on the side of the pseudo-polysilicon in the gate metal filling region.

[0118] S402: preparing a film layer to be etched on a surface of a device with a gate metal filling region to be formed.

[0119] S403: Etching the film layer to be etched until all the remaining pseudo polysilicon is just exposed, and forming a film layer slope as a device with formed gate metal.

[0120] It should be noted that in this embodiment, the film layer to be etched is etched until all the remaining pseudo-polysilicon is just exposed, and the bottom plane of the formed film layer slope is cut off along the remaining side wall to the direction of the remaining pseudo-polysilicon, and ends at the contact position between the remaining side wall and the remaining pseudo-polysilicon, that is, the upper surface of the remaining pseudo-polysilicon is just exposed, which can further widen the gate metal filling area and further improve the filling efficiency. This embodiment does not limit the specific position of the top of the formed film layer slope. Accordingly, the film layer slope formed in this embodiment can refer to Figure 5 , Figure 5 A schematic structural diagram of a formed gate metal device with a film layer slope provided in an embodiment of the present invention.

[0121] S404: Remaining pseudo polysilicon in the device having formed gate metal is removed to form a funnel-shaped gate metal filling region in the device having formed gate metal.

[0122] S405: filling the gate metal dielectric and the gate metal in the funnel-shaped gate metal filling region in sequence to complete the filling of the gate metal.

[0123] The gate metal filling method provided by the embodiment of the present invention includes etching pseudo-polysilicon of a preset height and a side wall of a preset height until they are flush in a device in which pseudo-polysilicon is filled in a gate metal filling area, so that the heights of the remaining pseudo-polysilicon and the remaining side wall are less than the height of the gate metal filling area; as a device for forming gate metal, the side wall is formed on the side of the pseudo-polysilicon in the gate metal filling area; a film layer to be etched is prepared on the surface of the gate metal filling area in the device for forming gate metal, the film layer to be etched is etched until all the remaining pseudo-polysilicon is just exposed, and a film layer slope is formed; as a device for forming gate metal, the remaining pseudo-polysilicon in the device for forming gate metal is removed to form a funnel-shaped gate metal filling area in the device for forming gate metal, and the gate metal medium and the gate metal are sequentially filled in the funnel-shaped gate metal filling area to complete the filling of the gate metal. The present invention improves the efficiency of filling the gate metal and the uniformity of the filled gate metal, avoids the occurrence of gate metal missing, by setting the gate metal filling area as a funnel-shaped gate metal filling area without changing the width of the gate metal after forming and maintaining the gate metal resistance. It is compatible with the existing technology and further improves the yield of the gate metal. By etching the film layer to be etched until all the remaining pseudo-polysilicon is just exposed and a film layer slope is formed, the gate metal filling area can be further widened, thereby further improving the filling efficiency.

[0124] Embodiment 4:

[0125] Please refer to Figure 7 , Figure 7A flow chart of another gate metal filling method provided by an embodiment of the present invention, the method may include:

[0126] S501: In a device in which pseudo-polysilicon is filled in a gate metal filling area, the pseudo-polysilicon of a preset height and the sidewall of a preset height are etched until they are flush, so that the heights of the remaining pseudo-polysilicon and the remaining sidewall are smaller than the height of the gate metal filling area, serving as a device for forming gate metal; the sidewalls are formed on the sides of the pseudo-polysilicon in the gate metal filling area.

[0127] S502: preparing a film layer to be etched on a surface of a device with a gate metal filling region to be formed.

[0128] S503: Etching the film layer to be etched until the remaining pseudo polysilicon is exposed, and forming a film layer slope whose top is at the same height as the substrate, as a device with formed gate metal.

[0129] It should be noted that in the present embodiment, the film layer to be etched is etched until the remaining pseudo-polysilicon is exposed, and the top of the formed film layer slope is at the same height as the upper surface of the substrate, thereby ensuring the widening of the gate metal filling area while ensuring the simplicity of etching to form the film layer slope, thereby further improving the efficiency of preparing the film layer slope. The present embodiment does not limit the cutoff position of the bottom plane of the formed film layer slope pointing along the remaining side wall in the direction of the remaining pseudo-polysilicon. It can be foreseen that when the cutoff position of the bottom of the film layer slope is at the contact position between the remaining side wall and the remaining pseudo-polysilicon, that is, all the remaining pseudo-polysilicon is just exposed, and at this time, the gate metal filling area can be widened to the greatest extent, thereby maximizing the gate metal filling efficiency. It should be noted that the film layer slope formed in the present embodiment can also refer to Figure 5 , Figure 5 A schematic structural diagram of a formed gate metal device with a film layer slope provided in an embodiment of the present invention.

[0130] S504: Remaining pseudo polysilicon in the device having formed gate metal is removed to form a funnel-shaped gate metal filling region in the device having formed gate metal.

[0131] S505: filling the gate metal dielectric and the gate metal in the funnel-shaped gate metal filling region in sequence to complete the filling of the gate metal.

[0132] The gate metal filling method provided by the embodiment of the present invention includes etching pseudo-polysilicon of a preset height and a side wall of a preset height until they are flush in a device in which pseudo-polysilicon is filled in a gate metal filling region, so that the heights of the remaining pseudo-polysilicon and the remaining side wall are less than the height of the gate metal filling region; as a device for forming gate metal, the side wall is formed on the side of the pseudo-polysilicon in the gate metal filling region; a film layer to be etched is prepared on the surface of the gate metal filling region in the device for forming gate metal, the film layer to be etched is etched until the remaining pseudo-polysilicon is exposed, and a film layer slope is formed with the top at the same height as the substrate; as a device for forming gate metal, the remaining pseudo-polysilicon in the device for forming gate metal is removed to form a funnel-shaped gate metal filling region in the device for forming gate metal, and a gate metal dielectric and a gate metal are sequentially filled in the funnel-shaped gate metal filling region to complete the filling of the gate metal. The present invention improves the efficiency of filling the gate metal and the uniformity of the filled gate metal without changing the width of the gate metal after forming and maintaining the resistance of the gate metal by setting the gate metal filling area as a funnel-shaped gate metal filling area, thereby avoiding the occurrence of gate metal missing, being compatible with the prior art, and further improving the yield of the gate metal. By etching the film layer to be etched until the remaining pseudo-polysilicon is exposed and the top of the formed film layer slope is at the same height as the upper surface of the substrate, while ensuring the widening of the gate metal filling area, the simplicity of etching to form the film layer slope is ensured, thereby further improving the efficiency of preparing the film layer slope.

[0133] To make the present invention easier to understand, the gate metal filling method may specifically include the following steps:

[0134] Step S41: In a device in which pseudo-polysilicon is filled in a gate metal filling area, a photoresist material is prepared on the entire surface of the gate metal filling area, the photoresist material on the upper side of the gate metal filling area is removed, and a side wall of a preset height is etched using a dry etching method so that the height of the remaining side wall is less than the height of the gate metal filling area. As a device to be etched, the pseudo-polysilicon in the device to be etched is dry-etched so that the remaining pseudo-polysilicon is flush with the remaining side wall, and the remaining photoresist material is removed. As a device with a gate metal to be formed, the side wall is the side of the pseudo-polysilicon formed in the gate metal filling area.

[0135] Step S42: depositing a silicon nitride substrate on the surface of the device with the gate metal to be formed, where a gate metal filling region is opened, to form a silicon nitride film layer to be etched.

[0136] Step S43: using a maskless etching method to etch the silicon nitride film layer to be etched until the remaining pseudo polysilicon is just completely exposed, and a film layer slope is formed with the top at the same height as the substrate, as a device with formed gate metal.

[0137] Step S44: removing the remaining pseudo polysilicon in the device with formed gate metal to form a funnel-shaped gate metal filling region in the device with formed gate metal.

[0138] Step S45: sequentially filling the funnel-shaped gate metal filling region with gate metal dielectrics and aluminum metal to complete the filling of the gate metal, wherein the gate metal dielectrics include thallium nitride dielectrics, titanium aluminum alloy dielectrics, titanium nitride dielectrics and titanium dielectrics.

[0139] Step S46: chemical mechanical polishing is performed on the surface filled with the gate metal until the formed film layer slope is completely polished away, so that the surface filled with the gate metal is flattened.

[0140] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0141] Finally, it should be noted that, in this article, relationships such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0142] The above is a detailed introduction to a gate metal filling method provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technicians in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A gate metal filling method, characterized in that: include: In a device in which a gate metal filling region is filled with pseudo polysilicon, the pseudo polysilicon of a preset height and the sidewall of a preset height are etched to be flush, so that the height of the remaining pseudo polysilicon and the remaining sidewall is less than the height of the gate metal filling region, as a device for forming gate metal; the sidewall is formed on the side of the pseudo polysilicon in the gate metal filling region; Preparing a film layer to be etched on a surface of the device having the gate metal to be formed and having the gate metal filling region opened therein; Etching the film layer to be etched to form a film layer slope at the height difference step formed between the substrate provided with the gate metal filling area and the remaining sidewalls, as a device with formed gate metal; Removing the remaining pseudo polysilicon in the device having formed gate metal to form a funnel-shaped gate metal filling region in the device having formed gate metal; The gate metal dielectric and the gate metal are sequentially filled in the funnel-shaped gate metal filling region to complete the filling of the gate metal.

2. The gate metal filling method according to claim 1, characterized in that: The etching of the film layer to be etched to form a film layer slope at the height difference step formed between the substrate provided with the gate metal filling area and the remaining sidewall as a device with formed gate metal, includes: The film layer to be etched is etched without a mask to form the film layer slope as the device of the formed gate metal.

3. The gate metal filling method according to claim 1, characterized in that: The etching of the film layer to be etched to form a film layer slope at the height difference step formed between the substrate provided with the gate metal filling area and the remaining sidewall as a device with formed gate metal, includes: The film layer to be etched is etched until the remaining pseudo polysilicon is exposed, and the film layer slope is formed to serve as the device of the formed gate metal.

4. The gate metal filling method according to claim 3, characterized in that: Etching the film layer to be etched until the remaining pseudo polysilicon is exposed and forming the film layer slope as the device of the formed gate metal, comprising: The film layer to be etched is etched until all the remaining pseudo polysilicon is just exposed, and the film layer slope is formed to serve as the device of the formed gate metal.

5. The gate metal filling method according to claim 3, characterized in that: Etching the film layer to be etched until the remaining pseudo polysilicon is exposed and forming the film layer slope as the device of the formed gate metal, comprising: The film layer to be etched is etched until the remaining pseudo polysilicon is exposed, and a film layer slope is formed with the top at the same height as the substrate, as the device of the formed gate metal.

6. The gate metal filling method according to claim 1, characterized in that: In the device in which the gate metal filling region is filled with pseudo polysilicon, the pseudo polysilicon of a preset height and the sidewall of a preset height are etched to be flush, so that the height of the remaining pseudo polysilicon and the remaining sidewall is less than the height of the gate metal filling region, as a device for forming gate metal, comprising: In the device in which the gate metal filling region is filled with the pseudo polysilicon, etching the sidewalls of a preset height so that the height of the remaining sidewalls is smaller than the height of the gate metal filling region as a device to be etched; The pseudo polysilicon in the device to be etched is etched to make the remaining pseudo polysilicon flush with the remaining sidewalls, so as to serve as the device for the gate metal to be formed.

7. The gate metal filling method according to claim 6, characterized in that: In the device in which the pseudo polysilicon is filled in the gate metal filling region, the sidewall of a preset height is etched so that the height of the remaining sidewall is less than the height of the gate metal filling region, as the device to be etched, comprising: In the device in which the gate metal filling region is filled with the pseudo polysilicon, the sidewalls of a preset height are etched by dry etching so that the height of the remaining sidewalls is smaller than the height of the gate metal filling region, as the device to be etched; Correspondingly, the dummy polysilicon in the device to be etched is etched so that the remaining dummy polysilicon is flush with the remaining sidewalls, and the device to be formed as the gate metal includes: The pseudo polysilicon in the device to be etched is dry-etched to make the remaining pseudo polysilicon flush with the remaining sidewalls, thereby forming the device for the gate metal to be formed.

8. The gate metal filling method according to claim 1, characterized in that: The step of preparing a film layer to be etched on a surface of a device having a gate metal filling region in which the gate metal filling region is opened in the device to be formed includes: A silicon nitride substrate is deposited on the surface of the device with the gate metal to be formed, where the gate metal filling region is opened, to form a silicon nitride film layer to be etched.

9. The gate metal filling method according to claim 6, characterized in that: In the device in which the pseudo polysilicon is filled in the gate metal filling region, the sidewall of a preset height is etched so that the height of the remaining sidewall is less than the height of the gate metal filling region, as the device to be etched, comprising: In the device in which the gate metal filling region is filled with the pseudo polysilicon, a photoresist material is prepared on the entire surface of the gate metal filling region; Removing the photoresist material on the upper side of the gate metal filling region, etching the sidewalls of a preset height so that the height of the remaining sidewalls is smaller than the height of the gate metal filling region, as the device to be etched; Correspondingly, the dummy polysilicon in the device to be etched is etched so that the remaining dummy polysilicon is flush with the remaining sidewalls, and the device to be formed as the gate metal includes: The pseudo polysilicon in the device to be etched is etched to make the remaining pseudo polysilicon flush with the remaining sidewalls, and the remaining photoresist material is removed to form the device with the gate metal to be formed.

10. The gate metal filling method according to claim 1, characterized in that: The gate metal dielectric and the gate metal are sequentially filled in the funnel-shaped gate metal filling region. After the gate metal filling is completed, the method further includes: The surface on which the gate metal filling is completed is subjected to chemical mechanical polishing to planarize the surface on which the gate metal filling is completed.

Images