Controlled etch of nitride features

Patent metadata

Field	Value
Publication number	US-2019019688-A1
Application number	US-201816036617-A
Country	US
Kind code	A1
Filing date	Jul 16, 2018
Priority date	Jul 17, 2017
Publication date	Jan 17, 2019
Grant date	—

Abstract

Methods of etching a semiconductor substrate may include applying an etchant to the semiconductor substrate. The semiconductor substrate may include an exposed region of an oxygen-containing material and an exposed region of a nitrogen-containing material. The methods may include heating the semiconductor substrate from a first temperature to a second temperature. The methods may include maintaining the semiconductor substrate at the second temperature for a period of time sufficient to perform an etch of the nitrogen-containing material relative to the oxygen-containing material. The methods may also include quenching the etch subsequent the period of time.

First claim

What is claimed is:

1 . A method of etching a semiconductor substrate, the method comprising:
applying an etchant to the semiconductor substrate, wherein the semiconductor substrate includes an exposed region of an oxygen-containing material and an exposed region of a nitrogen-containing material; heating the semiconductor substrate from a first temperature to a second temperature; maintaining the semiconductor substrate at the second temperature for a period of time sufficient to perform an etch of the nitrogen-containing material relative to the oxygen-containing material; and quenching the etch subsequent the period of time.

2 . The method of etching a semiconductor substrate of claim 1 , wherein the first temperature is below about 100° C.

3 . The method of etching a semiconductor substrate of claim 1 , wherein the second temperature is above about 100° C.

4 . The method of etching a semiconductor substrate of claim 1 , wherein the etchant comprises phosphoric acid at a concentration of at least about 60% by volume.

5 . The method of etching a semiconductor substrate of claim 4 , wherein the etchant further comprises tetraethyl orthosilicate.

6 . The method of etching a semiconductor substrate of claim 1 , wherein the period of time is less than or about 60 seconds.

7 . The method of etching a semiconductor substrate of claim 1 , wherein the semiconductor substrate is heated from the first temperature to the second temperature in less than or about 10 seconds.

8 . The method of etching a semiconductor substrate of claim 1 , wherein the quenching comprises contacting the semiconductor substrate with a volume of deionized water.

9 . The method of etching a semiconductor substrate of claim 8 , wherein the quenching reduces the etch rate by at least a factor of 10 in less than or about 10 seconds.

10 . A method of etching a semiconductor substrate, the method comprising:
applying an etchant to the semiconductor substrate, wherein the semiconductor substrate includes alternating layers of an oxide material and a nitride material; heating the semiconductor substrate from a first temperature to a second temperature greater than or about 100° C. in less than or about 30 seconds; maintaining the semiconductor substrate at the second temperature for a period of time; etching the nitride material relative to the oxide material at a selectivity greater than or about 10:1; and diluting the etchant to terminate the etching.

11 . The method of etching a semiconductor substrate of claim 10 , wherein the semiconductor substrate is heated to a temperature of above or about 150° C.

12 . The method of etching a semiconductor substrate of claim 10 , wherein less than or about 200 mL of etchant is applied to the semiconductor substrate.

13 . The method of etching a semiconductor substrate of claim 10 , further comprising rotating the semiconductor substrate during the heating.

14 . The method of etching a semiconductor substrate of claim 10 , wherein a rate of etching the nitride material is greater than or about 100 Å per minute.

15 . The method of etching a semiconductor substrate of claim 10 , wherein the nitride material is etched uniformly across the semiconductor substrate within a tolerance of less than or about 30% of an amount of the nitride material etched.

16 . The method of etching a semiconductor substrate of claim 10 , wherein diluting the etchant reduces a temperature of the etchant below about 100° C. in less than or about 10 seconds.

17 . The method of etching a semiconductor substrate of claim 10 , wherein the etchant comprises phosphoric acid at a concentration of at least about 75% by volume.

18 . The method of etching a semiconductor substrate of claim 10 , wherein the etchant further comprises at least one of soluble silicate or fluorine-containing material.

19 . The method of etching a semiconductor substrate of claim 10 , wherein additional etchant is not applied during the etching process.

20 . The method of etching a semiconductor substrate of claim 10 , wherein the amount of nitride material etched is less than or about 100 Å.

Assignees

• Applied Materials Inc

Inventors

• Bergman Eric J
• Klocke John L
• Sharbono Charles
• Hanson Kyle Moran
• Mchugh Paul

Classifications

• H10P14/69433

  the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz · CPC title

• H10P14/69215

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

• H10P14/662

  Laminate layers, e.g. stacks of alternating high-k metal oxides (adhesion layers or buffer layers H10P14/6508, H10P14/6548) · CPC title

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P72/7618

  characterised by a movable susceptor, stage or support, others than those only rotating on their own vertical axis, e.g. susceptors on a rotating carrousel · CPC title