3d material modification for advanced processing

Patent metadata

Field	Value
Publication number	US-2016163546-A1
Application number	US-201514613545-A
Country	US
Kind code	A1
Filing date	Feb 4, 2015
Priority date	Dec 8, 2014
Publication date	Jun 9, 2016
Grant date	—

Abstract

Embodiments of the present disclosure relate to precision material modification of three dimensional (3D) features or advanced processing techniques. Directional ion implantation methods are utilized to selectively modify desired regions of a material layer to improve etch characteristics of the modified material. For example, a modified region of a material layer may exhibit improved etch selectivity relative to an unmodified region of the material layer. Methods described herein are useful for manufacturing 3D hardmasks which may be advantageously utilized in various integration schemes, such as fin isolation and gate-all-around, among others. Multiple directional ion implantation processes may also be utilized to form dopant gradient profiles within a modified layer to further influence etching processes.

First claim

1 . A method of manufacturing a device structure, comprising:
depositing a film on a substrate having fin structures formed thereon; selecting an ion implantation angle in response to an aspect ratio defined by the one or more fin structures; selecting an ion dosage concentration and an implantation energy configured to modify compositional characteristics of the film; selecting an implantation temperature; directing ions toward the film along a trajectory defined by the angle and bombarding at least one surface of the film with the ions to form a modified portion of the film; and removing an unmodified portion of the film from the substrate.

2 . The method of claim 1 , further comprising:
repeating, one or more times, the selecting an ion implantation angle, the selecting an ion dosage concentration and implantation energy, the selecting an implantation temperature, and the directing ions and bombarding the film to generate a dopant gradient profile in the film.

3 . The method of claim 2 , wherein at least one of the selecting an ion implantation angle, the selecting an ion dosage concentration and implantation energy, and the selecting an implantation temperature is changed for each successive one or more repetitions.

4 . The method of claim 2 , wherein the dopant gradient profile is configured to change an etch rate of one or more regions of the film.

5 . The method of claim 1 , further comprising:
oxidizing exposed surfaces of the substrate and fin structures or depositing an insulator material over the substrate after the removing an unmodified portion of the film from the substrate.

6 . The method of claim 1 , wherein the film is deposited by an atomic layer deposition process and a top surface of the film has a density greater than a sidewall of the film.

7 . The method of claim 6 , wherein the film comprises one or more of a silicon nitride containing material, an oxide containing material, and aluminum oxide containing material, an amorphous silicon containing material, or a polysilicon containing material.

8 . The method of claim 1 , wherein the implantation temperature is between about 200° C. and about 500° C.

9 . The method of claim 1 , wherein the dosage concentration is greater than about 5E15 (ions/cm 3 ).

10 . The method of claim 1 , wherein the selecting an ion implantation angle comprises selecting a first angle between about +40° and about +70° and selecting a second angle between about −40° and about −70°.

11 . The method of claim 1 , wherein the ions comprise one or more of He+, H 3 +, H 2 +, H+, Ne+, F+, C+, CF x +, CH x +, C x H y , N+, B+, Si+, SiH+, SiH 2 +, SiH 3 +, BF+, BF 2 +, B 2 H x +, Xe+ and molecular silicon, carbon, boron, or boron carbide ions.

12 . A method of manufacturing a device structure, comprising:
depositing a silicon nitride film on a silicon substrate having one or more fin structures formed thereon; selecting an ion implantation angle in response to an aspect ratio defined by the one or more fin structures; selecting an ion dosage concentration greater than about 5E15 (ions/cm 3 ) and an implantation energy configured to modify compositional characteristics of the film; selecting an implantation temperature between about 15° C. and about 400° C.; directing ions toward the film along a trajectory defined by the angle and bombarding sidewalls and a top surface of the film with the ions to form a modified cap portion of the film; etching an unmodified portion of the film from the substrate using a fluorine containing etching process; and oxidizing exposed surfaces of the substrate and fin structures.

13 . The method of claim 12 , further comprising:
repeating one or more times the selecting an ion implantation angle, the selecting an ion dosage concentration and implantation energy, the selecting an implantation temperature, and the accelerating ions and bombarding the film to generate a dopant gradient profile in the film.

14 . The method of claim 13 , wherein at least one of the selecting an ion implantation angle, the selecting an ion dosage concentration and implantation energy, and the selecting an implantation temperature is changed for each successive one or more repetitions.

15 . The method of claim 13 , wherein the dopant gradient profile is configured to change an etch rate of one or more regions of the film.

16 . The method of claim 15 , wherein the modified cap portion has a notched region in response to the dopant gradient profile.

17 . A 3D hardmask structure, comprising:
a modified film layer disposed on a fin structure, the modified film layer having a top portion disposed over the fin structure and sidewall portions that extend adjacent to sidewalls of the fin structure, the modified film layer comprising:
an outer region having a first dopant concentration;
an intermediate region having a second dopant concentration less than the first dopant concentration; and
an inner region having a third dopant concentration less than the second dopant concentration.

18 . The 3D hardmask structure of claim 17 , wherein the inner region is disposed adjacent the sidewalls of the fin structure.

19 . The 3D hardmask structure of claim 18 , wherein the third dopant concentration is about 0 ions/cm 3 .

20 . The 3D hardmask structure of claim 17 , wherein the outer region, the intermediate region, and the inner region define a notched shape.

Assignees

• Applied Materials Inc

Inventors

• Godet Ludovic
• Nemani Srinivas D
• Chen Erica
• Xue Jun
• Yieh Ellie Y
• Dickerson Gary E

Classifications

• H10W10/181

  Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers · CPC title

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• H10P90/1906

  Preparing SOI wafers · CPC title

• H10P76/4083

  characterised by their behaviours during the lithography processes, e.g. soluble masks or redeposited masks · CPC title

• H10P76/405

  characterised by their composition, e.g. multilayer masks · CPC title