VNAND tensile thick TEOS oxide

Patent metadata

Field	Value
Publication number	US-10199388-B2
Application number	US-201615214104-A
Country	US
Kind code	B2
Filing date	Jul 19, 2016
Priority date	Aug 27, 2015
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

Embodiments of the present disclosure generally relate to an improved method for forming a dielectric film stack used for inter-level dielectric (ILD) layers in a 3D NAND structure. In one embodiment, the method comprises providing a substrate having a gate stack deposited thereon, forming on exposed surfaces of the gate stack a first oxide layer using a first RF power and a first process gas comprising a TEOS gas and a first oxygen-containing gas, and forming over the first oxide layer a second oxide layer using a second RF power and a second process gas comprising a silane gas and a second oxygen-containing gas.

First claim

The invention claimed is:

1. A method for processing a substrate, comprising:
positioning a substrate having a gate stack deposited thereon, the gate stack comprising a plurality of oxide layers and a plurality of nitride layers disposed alternatingly in a vertical arrangement perpendicular to a top surface of the substrate, and the gate stack having a staircase cross section;
forming on exposed surfaces of the gate stack a first oxide layer using a first RF power of about 150 W and a first process gas comprising a TEOS gas and a first oxygen-containing gas;
after the first oxide layer has reached a predetermined thickness, ramping up the first RF power to form an initiation layer of oxide over the first oxide layer;
after the initiation layer has reached a predetermined thickness, ramping up the RF power used to form the initiation layer while gradually decreasing the flow of the TEOS gas to form a transition layer of oxide on the initiation layer; and then
forming a second oxide layer over the transition layer using a second RF power that is different from the first RF power and a second process gas comprising a silane gas and a second oxygen-containing gas.

2. The method of claim 1 , wherein each of the first and second oxygen-containing gases comprises O 2 or N 2 O.

3. The method of claim 1 , wherein the first oxygen-containing gas and the TEOS gas are provided at first oxygen-containing gas:TEOS gas ratio of about 2:1 to about 6:1.

4. The method of claim 1 , wherein the first process gas further comprises a P-type or N-type dopant gas.

5. The method of claim 1 , wherein the first oxide layer has a tensile stress of about 80 MPa to about 300 MPa.

6. The method of claim 1 , wherein the first oxide layer has a thickness of about 10000 angstroms to about 30000 angstroms, and the second oxide layer has a thickness of about 8000 angstroms to about 15000 angstroms.

7. The method of claim 1 , further comprising:
after forming the second oxide layer, subjecting the substrate to a thermal anneal treatment in a nitrogen rich environment at a temperature of about 700° C. to about 850° C.

8. The method of claim 1 , wherein the initiation layer is formed by ramping up the first RF power from about 150 W to about 200 W.

9. The method of claim 8 , wherein the transition layer is formed by ramping up the RF power used to form the initiation layer from about 200 W to about 400 W.

10. A method for processing a substrate, comprising:
positioning a substrate having a gate stack deposited thereon;
forming a first oxide layer conformally on exposed surfaces of the gate stack using a first RF power of about 150 W and a first process gas comprising a TEOS gas and a first oxygen-containing gas;
after the first oxide layer has reached a predetermined thickness, ramping up the first RF power while continuing the flow of the TEOS gas and the first oxygen-containing gas to form an initiation layer of oxide over the first oxide layer;
after the initiation layer has reached a predetermined thickness, increasing the RF power used to form the initiation layer while gradually decreasing the flow of the TEOS gas to form a transition layer of oxide on the initiation layer; and then
forming a second oxide layer conformally over the transition layer using a second RF power that is different from the first RF power and a second process gas comprising a silane gas and a second oxygen-containing gas.

Assignees

• Applied Materials Inc
• Applied Mateerials Inc

Inventors

• Tsiang Michael Wenyoung
• Jha Praket P
• Han Xinhai
• Kim Bok Hoen
• Kim Sang Hyuk
• Ju Myung Hun
• Park Hyung Jin
• Kim Ryeun Kwan
• Son Jin Chul
• GNANAVELU Saiprasanna
• Kulkarni Mayur G
• Baluja Sanjeev
• Shahreza Majid K
• Foster Jason K

Classifications

• H10P95/062

  involving a dielectric removal step · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P32/20

  Diffusion for doping of insulating layers · CPC title

• H10P14/69215 Primary

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

• H10P14/6686

  the compound being a molecule comprising at least one silicon-oxygen bond and the compound having hydrogen or an organic group attached to the silicon or oxygen, e.g. a siloxane · CPC title