Method for selectively depositing a layer on a three dimensional structure

Patent metadata

Field	Value
Publication number	US-2016005607-A1
Application number	US-201414336893-A
Country	US
Kind code	A1
Filing date	Jul 21, 2014
Priority date	Jul 7, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

A method may include providing a substrate having a surface that defines a substrate plane and a substrate feature that extends from the substrate plane; directing an ion beam comprising angled ions to the substrate at a non-zero angle with respect to a perpendicular to the substrate plane, wherein a first portion of the substrate feature is exposed to the ion beam and wherein a second portion of the substrate feature is not exposed to the ion beam; directing molecules of a molecular species to the substrate wherein the molecules of the molecular species cover the substrate feature; and providing a second species to react with the molecular species, wherein selective growth of a layer comprising the molecular species and the second species takes place such that a first thickness of the layer grown on the first portion is different from a second thickness grown on the second portion.

First claim

What is claimed is:

1 . A method, comprising:
providing a substrate having a surface that defines a substrate plane and a substrate feature that extends from the substrate plane; directing an ion beam comprising angled ions to the substrate at a non-zero angle with respect to a perpendicular to the substrate plane, wherein a first portion of the substrate feature is exposed to the ion beam and wherein a second portion of the substrate feature is not exposed to the ion beam; directing molecules of a molecular species to the substrate wherein the molecules of the molecular species cover the substrate feature; and providing a second species to react with the molecular species, wherein selective growth of a layer comprising the molecular species and the second species takes place such that a first thickness of the layer grown on the first portion is different from a second thickness of the layer grown on the second portion.

2 . The method of claim 1 , further comprising providing the second species as reactive ions to the substrate before the directing the angled ions, wherein the reactive ions form a sub-monolayer on the substrate feature, wherein the angled ions remove the sub-monolayer on the first portion, and wherein the second thickness of the layer on the second portion is greater than the first thickness of the layer on the first portion.

3 . The method of claim 2 , wherein the reactive ions are oxygen and the molecules are silane.

4 . The method of claim 1 , wherein the angled ions comprise reactive ions that constitute the second species and are configured to react with the molecular species, and wherein the first thickness on the first portion is greater than the second thickness on the second portion.

5 . The method of claim 4 , wherein the angled ions are oxygen ions and the molecules are silane.

6 . The method of claim 1 further comprising modifying a plasma sheath boundary to generate the angled ions.

7 . The method of claim 6 , wherein the angled ions comprise an ion angular distribution that has a bimodal distribution of angles of incidence.

8 . The method of claim 7 , wherein the bimodal distribution is characterized by a peak at +/−5 degrees to +/−75 degrees with respect to the perpendicular.

9 . The method of claim 1 , wherein the ion beam to the substrate and directing molecules of a molecular species to the substrate comprise a process cycle that is effective to selectively deposit a monolayer of a compound comprising the molecular species and a second species.

10 . The method of claim 9 , further comprising performing at least one additional process cycle, wherein the layer comprises a plurality of monolayers on at least one of the first portion or second portion of the substrate feature.

11 . The method of claim 1 , wherein the second portion is shadowed by a second substrate feature wherein the angled ions do not impact the second portion.

12 . The method of claim 1 wherein the layer is a selectively grown dopant oxide, wherein the first thickness is greater than the second thickness, the method further comprising annealing the substrate, wherein a selectively doped region is formed in the substrate feature that is adjacent to the first portion.

13 . The method of claim 1 wherein the second thickness is zero.

14 . The method of claim 4 , wherein the angled ions are nitrogen ions and the molecules are silane.

15 . The method of claim 1 ,
wherein the substrate feature comprises a sidewall and an endwall that extends perpendicularly to the sidewall, wherein the directing the ion beam comprises providing an extraction aperture in an extraction plate that is elongated along a first direction that is parallel to sidewall, wherein the angled ions impinge upon the sidewall and do not impinge upon the endwall, and wherein the sidewall comprises the first portion and the endwall comprises the second portion.

16 . A method of selectively doping a three dimensional substrate feature on a substrate, comprising:
directing an ion beam comprising angled oxygen ions to the substrate at a non-zero angle with respect to a perpendicular to a substrate plane, wherein a first portion of the substrate feature is exposed to the ion beam and wherein a second portion of the substrate feature is not exposed to the ion beam; directing molecules of a molecular species that includes a dopant to the substrate wherein the molecules of the molecular species cover the substrate feature, wherein the directing the ion beam and directing the molecules generates selective growth of a dopant oxide layer comprising the dopant on the first portion but not on the second portion.

17 . The method of claim 16 further comprising annealing the substrate wherein a doped region is formed in the three dimensional substrate feature adjacent the first portion.

18 . The method of claim 16 wherein the substrate feature is a fin structure of a finFET device.

19 . A method of selectively doping a three dimensional substrate feature on a substrate, comprising:
exposing the substrate to an oxide plasma wherein the substrate feature is covered with a sub-monolayer of oxygen; directing an ion beam comprising angled ions to the substrate at a non-zero angle with respect to a perpendicular to a substrate plane, wherein a first portion of the substrate feature is exposed to the ion beam and wherein a second portion of the substrate feature is not exposed to the ion beam, wherein the sub-monolayer of oxygen is removed in the first portion and the sub-monolayer of oxygen remains in the second portion; directing molecules of a molecular species that includes a dopant to the substrate wherein the molecules of the molecular species cover the substrate feature, wherein the directing the ion beam and directing the molecules generates selective growth of a dopant oxide layer comprising the dopant on the second portion but not on the first portion.

20 . The method of claim 19 further comprising;
depositing a sealing layer on the substrate; and
annealing the substrate wherein a doped region is formed in the three dimensional substrate feature adjacent the second portion.

Assignees

• Varian Semiconductor Equipment

Inventors

• Russell Simon
• Omstead Thomas R
• Renau Anthony

Classifications

• H10P32/19

  Diffusion sources · CPC title

• H10P95/90

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

• H10P70/20

  Cleaning during device manufacture · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P32/1404

  using predeposition followed by drive-in of impurities into the semiconductor surface, e.g. predeposition from a gaseous phase · CPC title