Cyclic sequential processes for forming high quality thin films

Patent metadata

Field	Value
Publication number	US-2016244879-A1
Application number	US-201615001384-A
Country	US
Kind code	A1
Filing date	Jan 20, 2016
Priority date	Feb 23, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

Methods are described for a cyclical deposition and curing process. More particularly, the implementations described herein provide a cyclic sequential deposition and curing process for filling features formed on a substrate. Features are filled to ensure electrical isolation of features in integrated circuits formed on a substrate. The processes described herein use flowable film deposition processes that have been effective in reducing voids or seams produced in features formed on a substrate. However, conventional gap-filling methods using flowable films typically contain dielectric materials that have undesirable physical and electrical properties. In particular, film density is not uniform, film dielectric constant varies across the film thickness, film stability is not ideal, film refractive index is inconsistent, and resistance to dilute hydrofluoric acid (DHF) is not ideal in conventional flowable films. The cyclic sequential deposition and curing processes address the issues described herein to create films with higher quality and increased lifetime.

First claim

1 . A method for processing a substrate, comprising:
forming a first flowable film having a thickness in a feature of a substrate, wherein the thickness is less than the height of the feature, forming the first flowable film comprising:
depositing a first flowable film in the feature;
exposing the substrate to an oxygen containing plasma;
exposing the substrate to ultraviolet light; and
repeating the process of forming the first flowable film to form one or more layers of second flowable film over the first flowable film, wherein the first flowable film and the one or more layers of second flowable film together have a film thickness equal to or greater than the height of the feature.

2 . The method of claim 1 , wherein the depositing of the first flowable film comprises:
providing a silicon containing precursor to a processing region in a substrate processing chamber in which the substrate is disposed; providing a gas to a remote plasma system to form a plasma activated gas; introducing at least a portion of the plasma activated gas into the processing region; and reacting the plasma activated gas and the silicon containing precursor to form the flowable film in the feature.

3 . The method of claim 1 , wherein exposing the substrate to the oxygen containing plasma further comprises exposing the substrate to a nitrogen containing plasma.

4 . The method of claim 1 , wherein exposing the substrate to the oxygen containing plasma further comprises exposing the substrate to a carbon containing plasma.

5 . The method of claim 1 , wherein exposing the substrate to ultraviolet light further comprises positioning the substrate on a pedestal maintained below 100 degrees Celsius, while the substrate is exposed to ultraviolet light.

6 . The method of claim 1 , further comprising annealing the deposited film.

7 . The method of claim 1 , wherein when repeating the process of forming the first flowable film, the thickness of each of the first flowable film and the one or more layers of second flowable film increases each repetition of the process.

8 . The method of claim 1 , wherein the first flowable film and the one or more layers of second flowable film each have substantially the same thickness.

9 . The method of claim 1 , wherein the first flowable film is a non-oxide containing flowable film.

10 . A method for filling a feature in a substrate, comprising:
forming a flowable dielectric film having a thickness in the at least one feature, wherein the thickness is less than the height of the feature, wherein the forming of the flowable dielectric film comprises:
providing a silicon precursor to a processing region in a processing chamber in which a substrate is disposed;
forming a plasma; and
introducing at least a portion of the gas that was exposed to the plasma into the substrate processing region;
exposing the substrate to an oxygen containing plasma; exposing the substrate to ultraviolet light; and repeating the preceding steps to form additional layers of flowable film over the flowable film, wherein the several layers together form a flowable film stack having a film thickness equal to or greater than the height of the at least one feature.

11 . The method of claim 10 , wherein the flowable film stack has a uniform density.

12 . The method of claim 10 , wherein when repeating the process of forming the flowable film, the thickness of each of the additional layers of flowable film increases each repetition of the process.

13 . A method of forming a layer, the method comprising:
flowing a non-oxygen containing precursor over a patterned substrate disposed into a first substrate processing chamber; depositing a film having a thickness over the patterned substrate, wherein the thickness is less than the depth of a feature on the substrate; exposing the patterned substrate to a plasma; transferring the patterned substrate into a second substrate processing chamber equipped with an ultraviolet light source; exposing the patterned substrate to ultraviolet light provided by the ultraviolet light source; and repeating the preceding steps to form additional layers of flowable film over the flowable film, wherein the several layers together form a flowable film stack having a uniform density and a film thickness equal to or greater than the height of the at least one feature.

14 . The method of claim 13 , wherein the method is performed under continuously inert conditions.

15 . The method of claim 13 , wherein the plasma is an oxygen containing plasma.

16 . The method of claim 13 , wherein the plasma is a nitrogen containing plasma.

17 . The method of claim 13 , wherein the plasma is a carbon containing plasma.

18 . The method of claim 13 , wherein during the exposing the patterned substrate to the ultraviolet light, the patterned substrate is disposed on a pedestal maintained below 100 degrees Celsius.

19 . The method of claim 13 , further comprising annealing the deposited film.

20 . The method of claim 13 , wherein for each successive repetition, the thickness of the film is greater than the thickness of the film in the previous repetition.

Assignees

• Applied Materials Inc

Inventors

• Liang Jingmei
• Lee Jung Chan
• Guo Jinrui
• Srinivasan Mukund

Classifications

• C23C16/36

  Carbonitrides · CPC title

• C23C16/345

  Silicon nitride · CPC title

• C23C16/56

  After-treatment · CPC title

• C23C16/308

  Oxynitrides · CPC title

• C23C16/401

  containing silicon · CPC title