DE-112024002270-T5 - Semiconductor device and manufacturing process therefor

Abstract

A semiconductor device and a method for its fabrication are provided, wherein planarization by a contact plug is simple and barrier metal covering at a corner portion of an insulating film is effective. A semiconductor device 1 comprises a semiconductor layer 2, a silicide layer 3 provided within the semiconductor layer 2, a first insulating film 4 provided on the semiconductor layer 2 and having an opening 4A, a second insulating film 5 provided on a side wall of the opening 4A, a barrier metal 6 provided on the first insulating film 4, a corner portion 8 of the second insulating film 5, a side wall of the second insulating film 5, and on the silicide layer 3, and a contact plug 7 configured to fill a hole formed in the barrier metal 6 by the opening 4A. The corner portion 8 of the second insulating film 5 is rounded.

Inventors

• Masamitsu Ito
• Tatsunori Murata
• Yuji Yatsuda
• Koyo Kinoshita

Assignees

• MINEBEA POWER SEMICONDUCTOR DEVICE INC.

Dates

Publication Date

20260513

Application Date

20240710

Priority Date

20230719

Claims (9)

1. Semiconductor device comprising: a semiconductor layer; a silicide layer provided in the semiconductor layer; a first insulating film provided on the semiconductor layer and having an opening; a second insulating film provided on a side wall of the opening; a barrier metal provided on the first insulating film, a corner portion of the second insulating film, a side wall of the second insulating film, and on the silicide layer; and a contact plug configured to fill a hole formed in the barrier metal due to the opening, wherein the corner portion of the second insulating film is rounded.
2. Semiconductor device according to Claim 1 , wherein the rounded shape of the corner part of the second insulating film is formed by back-etching.
3. Semiconductor device according to Claim 1 , whereby the silicide layer is also provided under the second insulating film.
4. Semiconductor device according to Claim 1 , where the silicide layer is a silicide with the barrier metal.
5. Semiconductor device according to Claim 1 , where the barrier metal is a layered film consisting of two or more layers.
6. Semiconductor device according to Claim 1 , where the first insulating film is a single film.
7. A method for manufacturing a semiconductor device, comprising: an aperture formation process of forming an aperture in a first insulating film formed on a semiconductor layer by photolithography and etching; a second insulating film formation process of depositing a second insulating film on the first insulating film and within the aperture, and forming the second insulating film, having a rounded corner portion, on a side wall of the aperture by back-etching; a barrier metal formation process of depositing a barrier metal on the first insulating film, on the corner portion of the second insulating film, on the side wall of the second insulating film, and on the semiconductor layer in the aperture; a contact plug formation process of forming a contact plug configured to fill a hole formed in the barrier metal due to the aperture; and a silicide layer formation process of forming a silicide layer on at least a portion of the semiconductor layer within the aperture after the aperture formation process and before the contact plug formation process.
8. Method for manufacturing the semiconductor device according to Claim 7 , where the silicide layer formation process is a process of forming the silicide layer on an entire surface of the semiconductor layer within the aperture after the aperture formation process and before the second insulating film formation process.
9. Method for manufacturing the semiconductor device according to Claim 7 , where the silicide layer formation process is a process of forming a silicide with the barrier metal as the silicide layer after the barrier metal formation process and before the contact plug formation process.

Description

Technical field The present invention relates to a semiconductor device and a method for its manufacture. State of the art As a technique for connecting a top electrode and a semiconductor layer through a contact hole while planarizing a top side of a semiconductor device, there is a technique using a contact plug. For example, they describe 8 and 9 patent literature 1 describes a technique for forming a contact hole in an intermediate insulating film provided on a semiconductor substrate (semiconductor layer) by photolithography and etching, subsequently forming a barrier metal inside and outside the contact hole, subsequently forming silicide by heat treatment using a rapid thermal anneal (RTA), and subsequently forming a contact plug. Citation list Patent literature Patent literature 1: JP 2016-225 512 A Summary of the invention Technical problem The 12 and 13 show cross-sectional views which illustrate the problems in the process for manufacturing the semiconductor device according to the state of the art. As in 12 As shown, the semiconductor device 1 comprises a semiconductor layer 2, a silicide layer 3, a first insulating film 4, a plurality of openings 4A (contact holes) provided in the first insulating film 4, a barrier metal 6 formed from layered films of a first barrier metal 6A and a second barrier metal 6B, and a contact plug 7. If a metal film for forming the contact plug 7 is deposited, for example, by chemical vapor deposition (CVD), the metal film for forming the contact plug 7 cannot be deposited too thickly, as the probability of contamination increases with increasing film thickness. For this reason, as described in 12 It has been shown that a problem exists in that the interior of opening 4A cannot be sufficiently planarized if the diameter of opening 4A is large. Furthermore, as in 13 As shown, when an opening 4A is formed in the first insulating film 4 by photolithography and etching, since the corner parts 8 of the first insulating film 4 are angular, there was a problem that the covering of the barrier metal 6 formed on it is poor and the barrier metal 6 can detach from the corner parts 8 in some cases. One problem to be solved by the present invention is to provide a semiconductor device that can be easily planarized by means of a contact plug and has good coverage of the barrier metal at corner parts of an insulating film, as well as a method for its manufacture. Solution to the problem To solve the above problems, a semiconductor device according to the present invention comprises: a semiconductor layer; a silicide layer provided in the semiconductor layer; a first insulating film provided on the semiconductor layer and having an opening; a second insulating film provided on a side wall of the opening; a barrier metal provided on the first insulating film, a corner portion of the second insulating film, a side wall of the second insulating film and on the silicide layer; and a contact plug configured to fill a hole formed in the barrier metal due to the opening, the corner portion of the second insulating film being rounded. Furthermore, a method for fabricating a semiconductor device according to the present invention comprises: an aperture formation process of forming an aperture in a first insulating film formed on a semiconductor layer by photolithography and etching; a second insulating film formation process of depositing a second insulating film on the first insulating film and within the aperture, and forming the second insulating film, having a rounded corner portion, on a side wall of the aperture by back-etching; a barrier metal formation process of depositing a barrier metal on the first insulating film, on the corner portion of the second insulating film, on the side wall of the second insulating film, and on the semiconductor layer in the aperture; a contact plug formation process of forming a contact plug configured to fill a hole formed in the barrier metal due to the aperture; and a silicide layer formation process of forming a silicide layer on at least a portion of the semiconductor layer within the aperture after the Opening formation process and before the contact plug formation process. Advantageous effects of the invention According to the present invention, it is possible to realize a semiconductor device that can be easily planarized by means of a contact plug and has good coverage of barrier metals at corner parts of an insulating film, as well as a method for its manufacture. Brief description of the drawings 1 shows a cross-sectional view of a semiconductor device from Example 1.2 shows a flowchart illustrating a process for manufacturing the semiconductor device of Example 1.3 shows a cross-sectional view illustrating a method for manufacturing a semiconductor device of Example 1.4 shows a cross-sectional view illustrating a method for manufacturing a semiconductor device of Example 1.5 shows a cross-sectional view illustrating a method for manufacturi