Reduction of roughness on a sidewall of an opening

Patent metadata

Field	Value
Publication number	US-10923478-B2
Application number	US-201916258986-A
Country	US
Kind code	B2
Filing date	Jan 28, 2019
Priority date	Jan 28, 2019
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

Methods, apparatuses, and systems related to reduction of roughness on a sidewall of an opening are described. An example method includes forming a liner material on a first sidewall of an opening in a first silicate material and on a second sidewall of the opening in an overlying second silicate material, where the liner material is formed to a thickness that covers a roughness on the first sidewall extending into the opening. The example method further includes removing the liner material from the first sidewall of the opening and the second sidewall of the opening with a non-selective etch chemistry to reduce the roughness on the first sidewall.

First claim

What is claimed is:

1. A method, comprising:
forming a first silicate material on a substrate material;
forming an overlying second silicate material on the first silicate material, wherein the first silicate material is different from the second silicate material;
forming an opening through the first and the second silicate materials to conform to a width of the opening formed in the overlying second silicate material, wherein forming the opening comprises using a selective etch process having a selectivity for removal of a compound that forms the first silicate material on an exposed surface of a first sidewall of the opening in the first silicate material, and wherein the opening extends through the overlying second silicate material and through the first silicate material;
forming a liner material consisting of a same material as the first silicate material on the first sidewall of the opening in the first silicate material and on a second sidewall of the opening in the overlying second silicate material, wherein the liner material is formed to a thickness that covers a roughness on the first sidewall extending into the opening, and the roughness is caused by the selective etch process; extending into the opening; and
removing portions of the liner material from the first sidewall of the opening and the second sidewall of the opening with a non-selective etch chemistry having a same etch rate for the liner material as the roughness to remove the roughness on the first sidewall caused by the selective etch process.

2. The method of claim 1 , further comprising:
forming the opening in a substantially cylindrical configuration that extends through the overlying second silicate material and into the first silicate material; and
prior to forming the liner material, removing a taper of the opening in the first silicate material to conform to a diameter of the opening previously formed in the overlying second silicate material;
wherein the roughness results from the selectivity for removal of a chemical compound of a plurality of chemical compounds that form the first silicate material.

3. The method of claim 1 , further comprising determining the thickness of the liner material to form on the first and second sidewalls of the opening to cover the roughness based on a determination of a probable distance that the roughness extends into the opening.

4. A method, comprising:
forming a first silicate material on a substrate material;
forming an overlying second silicate material on the first silicate material, wherein the first silicate material is different from the second silicate material;
forming an opening through the first and second silicate materials to conform to a width of the opening formed in the overlying second silicate material, wherein forming the opening comprises using a selective etch process having a selectivity for removal of a compound that forms the first silicate material on an exposed surface of a first sidewall of the opening in the first silicate material, and wherein the opening extends through the overlying second silicate material and through the first silicate material;
depositing a liner material consisting of a same material as the first silicate material on the first sidewall of the opening in the first silicate material adjacent an underlying material and on a second sidewall of the opening in the overlying second silicate material to a thickness that covers a roughness on the first sidewall extending into the opening, and the roughness is caused by the selective etch process; and
etching portions of the liner material and the roughness on the first sidewall utilizing a non-selective etch chemistry having a same etch rate for the liner material as the roughness, until portions of the liner material is removed from the first and second sidewalls of the opening and the roughness on the first sidewall caused by the selective etch process is removed.

5. The method of claim 4 , further comprising:
forming the opening in a substantially cylindrical configuration that extends through the overlaying second silicate material and into the first silicate material; and
prior to depositing the liner material, etching a taper of the opening in the first silicate material, the taper having a diameter decreasing toward the underlying material, to conform to a diameter of the opening formed in the overlying second silicate material;
wherein the roughness results from an etch selectivity for a chemical compound of a plurality of chemical compounds that form the first silicate material.

6. The method of claim 4 , further comprising:
forming the first silicate material from a borophosphosilicate glass (BPSG) material including a silicon compound (SiO 2 ) doped with a boron compound (B 2 O 3 ) and a phosphorus compound (P 2 O 5 );
forming the overlying second silicate material from a tetraethyl orthosilicate (TEOS) material;
and
etching the liner material and the roughness on the first silicate material utilizing an etch chemistry that is non-selective to the liner material, the TEOS material, and the compounds of the BPSG material.

7. The method of claim 4 , wherein depositing the liner material comprises depositing a non-conformal liner, such that it does not follow a contour of the roughness, on the first sidewall of the opening in the first silicate material to cover the roughness on the first sidewall.

8. The method of claim 4 , further comprising utilizing a hydrogen fluoride (HF) based etch chemistry as the non-selective etch chemistry.

9. The method of claim 4 , further comprising:
forming a support structure for the overlaying second silicate material stacked on the first silicate material adjacent the substrate material by;
forming a first nitride material between the first silicate material and the overlaying second silicate material; and
forming a second nitride material on an opposite surface of the overlaying second silicate material;

wherein the support structure enables a stack of the first and the overlaying second silicate materials to be maintained in a static configuration relative to each other and the underlying material.

10. The method of claim 4 , further comprising:
forming the opening in the first silicate material to extend from the underlying first silicate material and through the overlying second silicate material;
wherein the opening has:
a height in a range of from 800 nanometers (nm) to 1,500 nm;
a width in a range of from 20 nm to 60 nm; and
an aspect ratio of the height to width in a range of from 25:1 to 50:1.

11. A method, comprising:
depositing an overlaying overlying second silicate material over a first silicate material and forming a second portion of an opening that extends through the overlying second silicate material, wherein the first silicate material is different from the second silicate material;
etching, via the second portion of the opening, a first portion of the opening into the first silicate material;
depositing a liner material on a first sidewall of the first portion of the opening in the first silicate material and on a second sidewall of the second portion of the opening in the overlying second silicate material to a thickness that covers a roughness on the first sidewall extending into the first portion of the opening, wherein the liner material is deposited such that is does not follow a contour of the roughness on a first side wall and the liner material consists of a same material as the first silicate material; and
etching portions of the liner material on the sidewalls of the first and the second portions of the opening, utilizing a non-selective etch chemistry having a same etch rate f

Assignees

• Micron Technology Inc

Inventors

• Gambee Christopher J
• Shreeram Devesh Dadhich
• Vasilyeva Irina V

Classifications

• H10P14/69215

  the material being a silicon oxide, e.g. SiO2 · CPC title

• H10P50/283 Primary

  by chemical means · CPC title

• H10D1/716 Primary

  having vertical extensions · CPC title

• H01G4/012

  Form of non-self-supporting electrodes · CPC title

• H01G4/008

  Selection of materials · CPC title