Lithographic Technique Incorporating Varied Pattern Materials

Patent metadata

Field	Value
Publication number	US-2016307769-A1
Application number	US-201514689288-A
Country	US
Kind code	A1
Filing date	Apr 17, 2015
Priority date	Apr 17, 2015
Publication date	Oct 20, 2016
Grant date	—

Abstract

A technique for patterning a workpiece such as an integrated circuit workpiece is provided. In an exemplary embodiment, the method includes receiving a workpiece having a material layer disposed on a substrate. A first set of fins is formed on the material layer, and a second set of fins is formed on the material layer interspersed between the first set of fins. The second set of fins have a different etchant sensitivity from the first set of fins. A first etching process is performed on the first set of fins and configured to avoid substantial etching of the second set of fins. A second etching process is performed on the second set of fins and configured to avoid substantial etching of the first set of fins. The material layer is etched to transfer a pattern defined by the first etching process and the second etching process.

First claim

1 . A method of patterning a workpiece, the method comprising:
receiving a workpiece having a material layer to be patterned; forming a first set of fins on the material layer; forming a second set of fins on the material layer and interspersed between the first set of fins, wherein the second set of fins have a different etchant sensitivity from the first set of fins; performing a first etching process on the first set of fins configured to avoid substantial etching of the second set of fins; performing a second etching process on the second set of fins configured to avoid substantial etching of the first set of fins; and etching the material layer to transfer a pattern defined by the first etching process and the second etching process to the material layer.

2 . The method of claim 1 , wherein the forming of the second set of fins includes:
applying a directed self assembly material to the workpiece between the first set of fins; and performing a curing process on the directed self assembly material that causes a component of the directed self assembly material to align as the second set of fins.

3 . The method of claim 2 , wherein the forming of the second set of fins further includes:
selectively removing another component of the directed self assembly material from between the second set of fins and the first set of fins without substantial etching of the second set of fins and the first set of fins.

4 . The method of claim 1 ,
wherein the performing of the first etching process includes patterning a resist to expose a subset of the first set of fins to be removed, wherein the patterned resist exposes at least one fin of the second set of fins, and wherein the first etching process is further configured such that the exposed at least one fin of the second set of fins remains after the first etching process.

5 . The method of claim 4 ,
wherein the resist is a first resist, wherein the performing of the second etching process includes patterning a second resist to expose a subset of the second set of fins to be removed, wherein the patterned second resist exposes at least one fin of the first set of fins, and wherein the second etching process is further configured such that the exposed at least one fin of the first set of fins remains after the second etching process.

6 . The method of claim 1 , wherein the forming of the first set of fins includes:
etching a mandrel material disposed on the material layer to define a vertical sidewall; forming a material of the first set of fins on the vertical sidewall of the mandrel material; and selectively removing the mandrel material while leaving the material of the first set of fins remaining.

7 . The method of claim 6 , wherein the forming of the material of the first set of fins on the vertical sidewall includes:
performing a conformal deposition of the material on the mandrel material and on the material layer; and performing an anisotropic etching of the material to remove a portion of the material disposed on a horizontal surface of the workpiece.

8 . The method of claim 1 , wherein the forming of the second set of fins includes forming a spacer material on a sidewall of the first set of fins and depositing a material of the second set of fins between the spacer material and between the fins of the first set of fins.

9 . The method of claim 8 , wherein the depositing of the material of the second set of fins includes performing a conformal deposition of the material on a sidewall of the spacer material and performing an anisotropic etching of the material to remove a portion of the material disposed on a horizontal surface of the workpiece.

10 . A method of fabrication comprising:
receiving a substrate having a material layer disposed thereupon; depositing a first fin material on the material layer to define a first set of fins; depositing a second fin material on the material layer between the first set of fins to define a second set of fins, wherein the second fin material has a different etchant sensitivity than the first fin material; performing a first fin-cut process on the first set of fins using an etching technique that selectively etches the first set of fins; performing a second fin-cut process on the second set of fins using an etching technique that selectively etches the second set of fins; and transferring to the material layer a pattern defined by a portion of the first set of fins remaining after the first fin-cut process and a portion of the second set of fins remaining after the second fin-cut process.

11 . The method of claim 10 , wherein the depositing of the second fin material on the substrate includes:
depositing a directed self assembly material; and curing the directed self assembly material such that the directed self assembly material forms the second set of fins and form a set of spacers between the first set of fins and the second set of fins.

12 . The method of claim 11 , wherein the depositing of the second fin material further includes:
selectively removing the set of spacers using an etching technique configured to leave the first set of fins and the second set of fins remaining on the material layer.

13 . The method of claim 10 , wherein the depositing of the first fin material includes forming a sacrificial material on the material layer;
patterning the sacrificial material; depositing the first fin material on sidewalls of the patterned sacrificial material to define the first set of fins; and removing the sacrificial material using an etching technique configured to leave the first fin set of fins remaining on the material layer.

14 . The method of claim 10 , wherein the performing of the first fin-cut process includes:
patterning a first resist to expose a portion of the first set of fins to be removed, wherein the patterned first resist exposes a portion of the second set of fins; and removing the exposed portion of the first set of fins using a technique configured to avoid removing the exposed portion of the second set of fins.

15 . The method of claim 10 , wherein the performing of the second fin-cut process includes:
patterning a second resist to expose a portion of the second set of fins to be removed, wherein the patterned second resist exposes a portion of the first set of fins; and removing the exposed portion of the second set of fins using a technique configured to avoid removing the exposed portion of the first set of fins.

16 - 20 . (canceled)

21 . A method comprising:
forming first fins over a material layer; forming second fins over the material layer, wherein second fins are interspersed between the first fins and the first fins have a different etchant sensitivity from the second fins; removing a first subset of the first fins to expose a first portion of the material layer underlying the removed first subset of the first fins; etching the first portion of the material layer to form a first trench; removing a first subset of the second fins to expose a second portion of the material layer underlying the removed first subset of the second fins; etching the second portion of the material layer to form a second trench; forming a fill material within the first and second trenches; and removing a second subset of the first fins and a second subset of the second fins.

22 . The method of claim 21 , wherein the first subset of the second fins is not removed during the removing of the first subset of the first fins.

23 . The method of claim 21 ,

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Tseng Chin-Yuan
• Hung Chi-Cheng
• Chen Chun-Kuang
• Chen De-Fang
• Liu Ru-Gun
• Gau Tsai-Sheng
• Lin Wei-Liang

Classifications

• H10P76/4085

  characterised by the processes involved to create the masks · CPC title

• H10P50/73 Primary

  using masks for insulating materials · CPC title

• H10P50/695

  characterised by the process involved to create the mask, e.g. lift-off masks or sidewalls or to modify the mask · CPC title

• H10D30/024

  of fin field-effect transistors [FinFET] · CPC title

• H01L21/3085

  Electricity · mapped topic