CN-114678324-B - Method for forming contact hole in semiconductor device and capacitor manufacturing method

CN114678324BCN 114678324 BCN114678324 BCN 114678324BCN-114678324-B

Abstract

The present disclosure provides a method of forming a contact hole in a semiconductor device, and a capacitor manufacturing method. The method of forming the contact hole in the semiconductor device may include, but is not limited to, at least one of the following steps. A semiconductor substrate is provided, and at least one stack is formed on the semiconductor substrate. A mask layer having a contact hole pattern is then formed over the entire stack, and the stack is etched based on the mask layer having the contact hole pattern to form a contact hole in the stack. The present disclosure forms a protective film on the inner sidewalls of the contact holes to protect the inner sidewalls of the contact holes before removing the mask layer. The mask layer is removed and the protective film formed as described above is removed. The method and the device can protect the inner side wall of the contact hole from being damaged by plasma gas for etching in the process of removing the mask layer, so that the increase of bending in the contact hole is effectively avoided. The present disclosure can significantly improve the yield of semiconductor devices, particularly semiconductor capacitors.

Inventors

ZHANG XUANYU
XU MIN
WU RONGZHE
YANG TAO
LI JUNFENG
WANG WENWU

Assignees

中国科学院微电子研究所
真芯(北京)半导体有限责任公司

Dates

Publication Date: 20260505
Application Date: 20201224

Claims (8)

1. A method of forming a contact hole in a semiconductor device, comprising: providing a semiconductor substrate, and forming a laminated layer on the semiconductor substrate; forming a mask layer with a contact hole pattern on the laminated layer; Etching the laminated layer based on the mask layer with the contact hole pattern to form a contact hole on the laminated layer; Forming a protective film on the inner side wall of the contact hole, wherein the protective film is used for protecting the contact hole, so that the bending degree of the inner side of the contact hole is not increased in the process of removing the mask layer, and the thickness of the protective film is smaller than that of the mask layer; removing the mask layer and the protective film at the same time; wherein, the forming the protective film on the inner side wall of the contact hole comprises: And performing an ashing process to form a silicon dioxide layer attached to the inner side wall of the contact hole as the protective film by using oxygen plasma generated by the ashing process and contact Kong Nagui atoms.
2. The method of forming a contact hole in a semiconductor device of claim 1, further comprising, after removing the mask layer: A cleaning process is performed to remove the protective film residue in the contact hole.
3. The method of forming a contact hole in a semiconductor device of claim 1, wherein forming a mask layer having a contact hole pattern over the stack layer comprises: sequentially forming a mask layer and a photoresist layer on the laminated layer; Patterning the photoresist layer through a photomask having a contact hole pattern; Etching the mask layer by taking the patterned photoresist layer as a mask so as to transfer the contact hole pattern onto the mask layer; and removing the patterned photoresist layer.
4. The method of forming a contact hole in a semiconductor device of claim 1, wherein forming a stack on the semiconductor substrate comprises: At least one molding layer and at least one support layer are disposed on the semiconductor substrate, the molding layer and the support layer comprising the stack.
5. A method of manufacturing a capacitor, characterized by comprising the method of forming a contact hole in a semiconductor device according to any one of claims 1 to 4, the contact hole being a capacitor node hole.
6. The method of manufacturing a capacitor according to claim 5, further comprising: Forming a plurality of bonding pads which are distributed at intervals on the semiconductor substrate before forming the lamination; after forming the capacitor node hole, each bonding pad is exposed.
7. The method of manufacturing a capacitor according to claim 6, further comprising: forming a lower electrode in the capacitor node hole; The stack is etched to form a support for supporting the lower electrode.
8. The method of manufacturing a capacitor according to claim 7, further comprising: And depositing a dielectric layer and an upper electrode into the capacitor node hole, wherein the dielectric layer is formed along the bottom wall and the inner side wall of the lower electrode, and the upper electrode is formed along the bottom wall and the inner side wall of the dielectric layer.

Description

Method for forming contact hole in semiconductor device and capacitor manufacturing method Technical Field The present disclosure relates to the field of semiconductor device processing technology, and more particularly, to a method for forming a contact hole in a semiconductor device and a method for manufacturing a capacitor. Background As semiconductor devices become more and more integrated, it is often required to form contact holes with a larger aspect ratio, wherein the capacitance node holes in semiconductor capacitors are most representative. In forming the capacitor node holes by etching, two conditions must be satisfied, (1) adjacent capacitor node holes must be separated, (2) electrodes deposited by subsequent processes must be able to contact the underlying pads. However, when forming the capacitor node hole, a bend (Bowing) is inevitably formed in the capacitor node hole. Moreover, the degree of bending (Bowing) becomes large in the subsequent process, resulting in a significant decrease in the yield of the semiconductor device. Therefore, how to effectively reduce the bending degree of the capacitor node hole is an important point of technical problems and constant researches to be solved by those skilled in the art. Disclosure of Invention In order to solve the problems of the existing processing technology of the semiconductor device, the disclosure provides a method for forming a contact hole in the semiconductor device and a method for manufacturing a capacitor. To achieve the above technical object, the present disclosure provides a method of forming a contact hole in a semiconductor device. The method may include, but is not limited to, at least one of the following steps. A semiconductor substrate is provided and at least one stack is formed on the semiconductor substrate. A mask layer having a contact hole pattern is then formed over the entire stack, and the stack is etched based on the mask layer having the contact hole pattern to form a contact hole in the stack. The present disclosure forms a protective film on the inner sidewalls of the contact holes to protect the inner sidewalls of the contact holes before removing the mask layer. Then, the protective film formed as described above is removed while the mask layer is removed. To achieve the above technical object, the present disclosure can also provide a semiconductor capacitor manufacturing method, which may include, but is not limited to, a method of forming a contact hole in a semiconductor device in any of the embodiments of the present disclosure. The contact hole may be a capacitor node hole. The method has the beneficial effects that the method can protect the inner side wall of the contact hole from being damaged by plasma gas for etching in the process of removing the mask layer so as to avoid the increase of bending (Bowing) in the contact hole. Therefore, the semiconductor device miniaturization requirement is met, and meanwhile, the yield of the semiconductor device can be obviously improved, and particularly the yield of the semiconductor capacitor is improved. The present disclosure does not require a subversion of existing processing techniques for the entire semiconductor device processing. And the processing time of the semiconductor capacitor based on the present disclosure is almost the same as that of the conventional process, and the processing cost of the semiconductor capacitor based on the present disclosure is also almost the same as that of the conventional process. It can be seen that the present disclosure has a wide range of application scenarios. Drawings Fig. 1 illustrates a schematic cross-sectional structure of a device after a stack is formed on a semiconductor substrate in one or more embodiments of the present disclosure. Fig. 2 illustrates a schematic cross-sectional structure of a device after forming a mask layer and a photoresist layer on the stack in one or more embodiments of the present disclosure. Fig. 3 illustrates a schematic cross-sectional view of a device after a photomask is disposed over a photoresist layer in one or more embodiments of the present disclosure. Fig. 4 illustrates a schematic cross-sectional structure of a device after patterning a photoresist layer to form a contact hole pattern in one or more embodiments of the present disclosure. Fig. 5 is a schematic diagram illustrating a cross-sectional structure of a device after etching a mask layer using a patterned photoresist layer as a mask in one or more embodiments of the present disclosure. Fig. 6 illustrates a schematic cross-sectional structure of a device after etching a stack to form a contact hole based on a mask layer having a contact hole pattern in one or more embodiments of the present disclosure. Fig. 7 is a schematic cross-sectional view of a device after forming a protective film on inner sidewalls of contact holes in one or more embodiments of the present disclosure. Fig. 8 illustrates a schematic cros