# US 10,504,851 B2 · Structure and method to improve overlay performance in semiconductor devices

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,504,851 B2
- Document ID: US10504851B2
- Status: Granted
- Kind: B2
- Application number: 15/904,853
- Filed: 2018-02-26
- Published: 2019-08-29
- Granted: 2019-12-10
- Earliest claimed: 2018-02-26
- Assignees: Globalfoundries Inc.
- Applicants: Globalfoundries Inc.
- Inventors: Cung D. Tran; Huaxiang Li; Bradley Morgenfeld; Xintuo Dai; Sanggil Bae; Rui Chen; Md Motasim Bellah; Dongyue Yang; Minghao Tang; Christian J. Ayala; Ravi Prakash Srivastava; Kripa Nidhan Chauhan; Pavan Kumar Chinthamanipeta Sripadarao
- Web page: https://patentgrep.com/patent/US10504851B2

## CPC

- H10W 46/00: Marks applied to devices, e.g. for alignment or identification
- G03F 7/16: Coating processes; Apparatus therefor (applying coatings to base materials in general B05; applying photosensitive compositions to base for photographic purposes G03C1/74)
- G03F 9/7076: {Mark details, e.g. phase grating mark, temporary mark}
- G03F 9/708: {Mark formation}
- G03F 9/7084: {Position of mark on substrate, i.e. position in (x, y, z) of mark, e.g. buried or resist covered mark, mark on rearside, at the substrate edge, in the circuit area, latent image mark, marks in plural levels}
- G03F 9/7088: {Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection}
- H10P 76/2041: {Photolithographic processes}
- G03F 7/20: Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00)
- G03F 7/2002: {with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image}
- G03F 7/70633: {Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching}
- G03F 7/70683: {Mark designs}
- H10W 20/43: Layouts of interconnections
- H10W 46/301: {for alignment}
- H10W 70/611: {for connecting multiple chips together}
- H10W 70/65: Shapes or dispositions of interconnections
- H10W 70/685: comprising multiple insulating layers
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G)
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

In an exemplary method, a first layer is formed on a substrate. First overlay marks are formed in a first zone of the first layer. A non-transparent layer is formed on top of the first layer. At least a portion of the non-transparent layer is removed from an area above the first zone of the first layer. This provides optical access to the first overlay marks. A second layer is formed on top of the non-transparent layer. Second overlay marks are formed in a second zone of the second layer. Position information is obtained from each of the first overlay marks and the second overlay marks.

## Claims

### Claim 1

A method, comprising:
forming a first layer of a multilayer device on a substrate;
forming first overlay marks in a first zone of the first layer;
forming first intermediate layers on top of the first layer of the multilayer device and the first overlay marks;
forming a non-transparent layer on top of the first intermediate layers;
forming a window in the non-transparent layer by removing only a portion of the non-transparent layer from a preselected area of the non-transparent layer, wherein the preselected area is vertically aligned on the first zone of the first layer and the window provides optical access to the first overlay marks;
forming second intermediate layers on top of the window and the non-transparent layer;
forming a second layer on top of the second intermediate layers and the window;
forming second overlay marks in a second zone of the second layer; and
obtaining position information from each of the first overlay marks and the second overlay marks by balancing optical contrast intensity between the first overlay marks and the second overlay marks.

### Claim 2 (depends on 1)

The method according to claim 1, wherein forming a window in the non-transparent layer comprises etching the non-transparent layer.

### Claim 3 (depends on 2)

The method according to claim 2, further comprising:
forming a patterned photoresist on the non-transparent layer on top of a preselected portion of the first zone of the first layer.

### Claim 4 (depends on 3)

The method according to claim 3, further comprising:
performing one or more lithographic processes on the non-transparent layer to remove a portion of the non-transparent layer from the preselected area vertically aligned with the preselected portion of the first zone of the first layer.

### Claim 5 (depends on 1)

The method according to claim 1, further comprising:
using the first overlay marks and the second overlay marks to position structural features on the substrate.

### Claim 6 (depends on 5)

The method according to claim 5, further comprising:
determining an overlay accuracy of structural features formed on the substrate based upon the position information obtained from each of the first overlay marks and the second overlay marks.

### Claim 7 (depends on 1)

The method according to claim 1, wherein the first overlay marks and the second overlay marks have different patterns.

### Claim 8

A method of forming a semiconductor device, comprising:
providing a substrate;
depositing a first layer of material on the substrate, the first layer of material having a top surface and a bottom surface;
forming first overlay marks in a zone of the first layer of material;
forming first intermediate layers on top of the first layer of material and the first overlay marks;
forming a layer of non-transparent material on top of the first layer of material and the first intermediate layers, the layer of non-transparent material having a top surface and a bottom surface, the bottom surface of the layer of non-transparent material contacting the top surface of the first intermediate layers, wherein the layer of non-transparent material covers the zone of the first layer of material;
forming a window in the layer of non-transparent material by selectively removing only a portion of the layer of non-transparent material, the area being vertically aligned with the zone of the first layer of material, wherein the window provides optical access to the first overlay marks;
forming second intermediate layers on top of the window and the non-transparent layer;
forming a second layer of material on top of the second intermediate layers and the window, the second layer of material having a top surface and a bottom surface, the bottom surface of the second layer of material contacting the top surface of the second intermediate layers;
forming second overlay marks in the second layer of material; and
using the first overlay marks and the second overlay marks to position structural features on the substrate by balancing optical contrast intensity between the first overlay marks and the second overlay marks.

### Claim 9 (depends on 8)

The method according to claim 8, wherein forming a window in the layer of non-transparent material comprises etching the layer of non-transparent material.

### Claim 10 (depends on 9)

The method according to claim 9, further comprising:
forming a patterned photoresist on the layer of non-transparent material on top of a preselected portion of the zone of the first layer of material.

### Claim 11 (depends on 10)

The method according to claim 10, further comprising:
performing one or more lithographic processes on the layer of non-transparent material to remove a portion of the layer of non-transparent material from the area vertically aligned with the preselected portion of the zone of the first layer of material.

### Claim 12 (depends on 8)

The method according to claim 8, further comprising:
obtaining position information from each of the first overlay marks and the second overlay marks.

### Claim 13 (depends on 12)

The method according to claim 12, further comprising:
determining an overlay accuracy of structural features formed on the substrate based upon the position information obtained from each of the first overlay marks and the second overlay marks.

### Claim 14 (depends on 8)

The method according to claim 8, wherein the first overlay marks and the second overlay marks have different patterns.

### Claim 15

A method of forming a multilayer device, comprising:
forming a first layer of material on a substrate;
forming first overlay marks in a first zone of the first layer of material;
forming first intermediate layers on top of the first layer of material and the first overlay marks;
forming a layer of non-transparent material on top of the first layer of material and the first intermediate layers, wherein the layer of non-transparent material covers the first intermediate layers and the first zone of the first layer of material;
forming a window in the layer of non-transparent material by selectively removing only a portion of the layer of non-transparent material from a preselected area of the layer of non-transparent material, wherein the preselected area of the layer of non-transparent material is vertically aligned on the first zone of the first layer of material and the window provides optical access to the first overlay marks;
forming second intermediate layers on top of the window and the layer of non-transparent material;
forming a second layer of material on top of the second intermediate layers and the window; the second layer of material having a top surface and a bottom surface, the bottom surface of the second layer of material contacting the top surface of the second intermediate layers;
forming second overlay marks in a second zone of the second layer of material; and
positioning structural features on the substrate by balancing optical contrast intensity between the first overlay marks and the second overlay marks.

### Claim 16 (depends on 15)

The method according to claim 15, further comprising:
obtaining position information from each of the first overlay marks and the second overlay marks.

### Claim 17 (depends on 16)

The method according to claim 16, further comprising:
determining an overlay accuracy of structural features formed on the substrate based upon the position information obtained from the first overlay marks and the second overlay marks.

### Claim 18 (depends on 15)

The method according to claim 15, wherein the first overlay marks and the second overlay marks have different patterns.

### Claim 19 (depends on 15)

The method according to claim 15, further comprising:
forming a patterned photoresist on the layer of non-transparent material on top of the preselected area of the first zone of the first layer of material.

### Claim 20 (depends on 19)

The method according to claim 19, further comprising:
performing one or more lithographic processes on the layer of non-transparent material to form the window in the layer of non-transparent material.