Dry development and image transfer of si-containing self-assembled block copolymers

Patent metadata

Field	Value
Publication number	US-2016141184-A1
Application number	US-201414542903-A
Country	US
Kind code	A1
Filing date	Nov 17, 2014
Priority date	Nov 17, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

Provided herein are methods of selectively etching silicon-containing block copolymer (BCP) materials. The methods involve exposing a BCP material that includes at least one silicon-containing block and at least one non-silicon-containing block to a plasma that has a reducing chemistry. The reducing plasma selectively removes the non-silicon-containing block, the silicon-containing block to be used in further processing. In some embodiments, the silicon-containing block is used as an etch mask. The reducing plasma reduces or eliminates profile bowing and undercut of the silicon-containing domains, allowing processing of high aspect ratio features. Examples of reducing chemistries include nitrogen (N 2 ), hydrogen (H 2 ), ammonia (NH 3 ), hydrazine (N 2 H 4 ), and mixtures thereof. Also provided are apparatuses to perform the methods.

First claim

What is claimed is:

1 . A method comprising:
providing a block copolymer (BCP) thin film on a substrate, the BCP thin film having microphase-separated domains of a silicon-containing block and a non-silicon-containing block; and exposing the BCP thin film to a reducing plasma to selectively remove the non-silicon-containing block.

2 . The method of claim 1 , further comprising exposing the BCP thin film to an oxidizing plasma prior to exposing the BCP thin film to a reducing plasma

3 . The method of claim 2 , wherein the BCP thin film is exposed to the oxidizing plasma for a first duration and is exposed to the reducing plasma for a second duration, the second duration being longer than the first duration.

4 . The method of claim 2 , wherein the BCP thin film is exposed to the oxidizing plasma for a first duration and is exposed to the reducing plasma for a second duration, the second duration being shorter than or equal to the first duration.

5 . The method of claim 2 , wherein a pressure in a chamber that houses the substrate is higher during exposure to the reducing plasma than during exposure to the oxidizing plasma.

6 . The method of claim 2 , wherein a pressure in a chamber that houses the substrate is the same during exposure to the reducing plasma as during exposure to the oxidizing plasma.

7 . The method of claim 2 , wherein a pressure in a chamber that houses the substrate is different during exposure to the reducing plasma than during exposure to the oxidizing plasma.

8 . The method of claim 1 , further comprising etching a layer underlying the BCP thin film using the silicon-containing block as an etch mask.

9 . The method of claim 1 , wherein the reducing plasma is a nitrogen-containing plasma.

10 . The method of claim 9 , wherein the reducing plasma is a hydrogen-containing plasma.

11 . The method of claim 1 , where the reducing plasma is generated from a process including one or more of: nitrogen (N 2 ), hydrogen (H 2 ), ammonia (NH 3 ), and hydrazine (N 2 H 4 ).

12 . The method of claim 1 , wherein the silicon-containing block is an organosilicon polymer.

13 . The method of claim 1 , wherein the silicon-containing block is one of poly(dimethylsiloxane) (PDMS), polyferrocenyldimethylsilane (PFDMS), poly(ferrocenylsilane) (PFS), poly(methylphenylsiloxane) (PMPS), poly(4-(bis(trimethylsilyl)methyl)styrene), poly(4-(pentamethyldisiloxymethyl)styrene), poly(4-(bis(trimethylsilyl)methyl)styrene), poly(trimethylsilylstyrene) (PTMSS), poly(4-pentamethyldisilylstyrene) (PDSS), poly(4-(trimethylsilyl)phenylmethylsilane), poly(phenylmethylstyrene), poly(trimethylsilyl styrene), and poly(methyltrimethylsilylmethacrylate) (PTMSM).

14 . The method of claim 1 , wherein the non-silicon-containing block is one of poly(methylmethacrylate) (PMMA), polystyrene (PS), poly(4-methoxystyrene) (PMOST), polyisoprene (PI), poly(lactic acid) (PLA), poly(ethylene oxide) (PEO), poly(2-vinylpyridine) (P2VP), poly(4-fluorostyrene) (P4FS), and poly(cyclohexylethylene) (PCHE).

15 . The method of claim 1 , wherein the placement of the microphase-separated domains is in accordance with a chemical or topographical substrate pattern used to direct self-assembly of the BCP thin film.

16 . The method of claim 1 , further comprising forming a silicon nitride layer on the surface of the domains of the silicon-containing block.

17 . The method of claim 1 , further comprising forming a silicon-rich layer on the surface of the domains of the silicon-containing block.

18 . The method of claim 2 , further comprising forming a silicon oxide layer on the surface of the domains of the silicon-containing block.

19 . The method of claim 1 , wherein the domains of the silicon-containing block have substantially straight sidewalls after the selective removal.

20 . The method of claim 1 , wherein the domains of the BCP thin film are oriented perpendicular to the substrate.

21 . The method of claim 1 , wherein the domains of the BCP thin film are oriented parallel to the substrate.

22 . The method of claim 1 , wherein the reducing plasma is a capacitively-coupled plasma.

23 . The method of claim 1 , wherein the reducing plasma is an inductively-coupled plasma.

24 . An apparatus comprising:
a chamber including a substrate support; a plasma source connected to the chamber and capable of generating a plasma in the chamber; a gas inlet to the chamber; and a controller, the controller comprising instructions for:
receiving a substrate having a block copolymer (BCP) thin film thereon, the BCP thin film including microphase-separated domains of a silicon-containing block and a non-silicon-containing block;
inletting through the gas inlet into the chamber a process gas including nitrogen-containing and hydrogen-containing compounds; and
generating a plasma in the chamber to selectively remove the non-silicon-containing block.

Assignees

• Lam Res Corp

Inventors

• Sirard Stephen M

Classifications

• H10P76/4085

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

• H10P50/287

  by chemical means · CPC title

• H01L21/3088 Primary

  Electricity · mapped topic

• H01L21/30604

  Electricity · mapped topic

• H01L21/67069

  Electricity · mapped topic