# US 12,218,004 B2 · Method for forming semiconductor structure

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- Number: US 12,218,004 B2
- Document ID: US12218004B2
- Status: Granted
- Kind: B2
- Application number: 17/229,255
- Filed: 2021-04-13
- Published: 2022-03-31
- Granted: 2025-02-04
- Earliest claimed: 2020-09-30
- Assignees: Semiconductor Manufacturing International (Shanghai) Corporation; Semiconductor Manufacturing International (Beijing) Corporation
- Applicants: Semiconductor Manufacturing International (Shanghai) Corporation; Semiconductor Manufacturing International (Beijing) Corporation
- Inventors: He Zuopeng; Yang Ming; Bei Duohui
- Web page: https://patentgrep.com/patent/US12218004B2

## CPC

- H10W 20/075: {of multilayered thin functional dielectric layers}
- H10W 20/089: {using processes for implementing desired shapes or dispositions of the openings, e.g. double patterning}
- H10P 50/73: {using masks for insulating materials}
- H10P 76/4085: {characterised by the processes involved to create the masks}
- H10P 76/4088: {Processes for improving the resolution of the masks}
- H10W 20/056: {by filling conductive material into holes, grooves or trenches}
- H10W 20/062: {by smoothing of conductive parts, e.g. by planarisation}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A method for forming a semiconductor structure is provided. In one form, a method includes: providing a base; forming a pattern memory layer on the base, where at least a first trench and a second trench are provided on the pattern memory layer, where an extending direction of the first trench is parallel to an extending direction of the second trench, and the first trench and the second trench are formed using different masks; and forming mandrel lines separated on the base at positions of the base that correspond to the first trench and the second trench. By using the method, a problem that a photoresist peels off during etching due to an elongated shape when separated mandrel lines are directly formed can be avoided. Further, a problem of a relatively high requirement on a filling material when the mandrel lines are formed directly by using a plurality of photolithography processes can be avoided, to lower the requirement on the filling material.

## Claims

### Claim 1

A method for forming a semiconductor structure, comprising:
providing a base;
forming a pattern memory layer on the base, wherein at least a first trench and a second trench are provided on the pattern memory layer, an extending direction of the first trench is parallel to an extending direction of the second trench, and the first trench and the second trench are formed using different masks, a material of the pattern memory layer is silicon oxide and is not silicon nitride; and
forming mandrel lines separated on the base at positions of the base that correspond to the first trench and the second trench, a material of the mandrel lines consists of at least one of amorphous carbon, a photoresist, or polycrystalline silicon.

### Claim 2 (depends on 1)

The method for forming a semiconductor structure according to claim 1, wherein:
before forming a pattern memory layer on the base, the method further comprises: forming a mandrel material layer on the base; and
the step of forming mandrel lines separated on the base comprises:
forming a sacrificial layer filling the first trench and the second trench;
removing the pattern memory layer; and
etching the mandrel material layer using the sacrificial layer as a mask, to form the mandrel lines separated on the base.

### Claim 3 (depends on 2)

The method for forming a semiconductor structure according to claim 2, wherein:
after the forming a sacrificial layer, before the removing the pattern memory layer, the method further comprises:
etching the sacrificial layer, to form a sacrificial layer isolation opening; and
the step of etching the mandrel material layer using the sacrificial layer as a mask, to form the mandrel lines separated on the base comprises:
etching the mandrel material layer using the sacrificial layer on which the sacrificial layer isolation opening is formed as a mask, to form the mandrel lines separated on the base.

### Claim 4 (depends on 2)

The method for forming a semiconductor structure according to claim 2, wherein a material of the sacrificial layer is silicon nitride.