Deposition of low fluorine tungsten by sequential cvd process

Patent metadata

Field	Value
Publication number	US-2016351401-A1
Application number	US-201514723270-A
Country	US
Kind code	A1
Filing date	May 27, 2015
Priority date	May 27, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

Provided herein are methods of depositing bulk tungsten by sequential CVD pulses, such as by alternately pulsing tungsten hexafluoride and hydrogen gas in cycles of temporally separated pulses. Some methods include depositing a tungsten nucleation layer at low pressure followed by deposition of bulk tungsten by sequential CVD to form low stress tungsten films with low fluorine content. Methods described herein may also be performed in combination with non-sequential CVD deposition and fluorine-free tungsten deposition techniques.

First claim

1 . A method of filling a feature comprising:
(a) exposing a substrate in a chamber to alternating pulses of a reducing agent and a tungsten-containing precursor to deposit a tungsten nucleation layer on the substrate; and (b) exposing the substrate to alternating pulses of hydrogen and a tungsten-containing precursor to deposit a bulk tungsten layer over the tungsten nucleation layer, wherein the chamber pressure during (a) is no more than 10 Torr.

2 . The method of claim 1 , further comprising, (c) exposing the substrate to a reducing agent and a tungsten-containing precursor simultaneously to deposit a second bulk tungsten layer.

3 . The method of claim 2 , further comprising, (d) performing (c) every 2 or more cycles of (b), wherein a cycle of (b) comprises a pulse of hydrogen and a pulse of the tungsten-containing precursor.

4 . The method of claim 1 , wherein (b) is performed in cycles comprising a pulse of hydrogen and a pulse of the tungsten-containing precursor, and each cycle forms a submonolayer having a thickness of at least about 0.3 Å.

5 . The method of claim 1 , wherein the tungsten-containing precursor in (a) is different from the tungsten-containing precursor in (b).

6 . The method of claim 5 , wherein the tungsten-containing precursor in (a) is fluorine-free.

7 . The method of claim 1 , wherein the deposited tungsten has a tensile stress less than about 1 GPa per 500 Å deposited.

8 . (canceled)

9 . (canceled)

10 . (canceled)

11 . (canceled)

12 . A method of filling a feature comprising:
(a) exposing the substrate to alternating pulses of hydrogen and a tungsten-containing precursor to deposit a bulk tungsten layer over the substrate; and (b) exposing the substrate to a tungsten-containing precursor and a reducing agent simultaneously to deposit a second bulk tungsten layer over the substrate.

13 . The method of claim 12 , wherein (a) and (b) are repeated sequentially.

14 . The method of claim 12 , wherein the tungsten-containing precursor in (b) is a fluorine-free tungsten-containing precursor selected from the group consisting of metal-organic tungsten-containing precursors, tungsten chlorides, and tungsten hexacarbonyl.

15 . The method of claim 12 , wherein the tungsten-containing precursor in (a) is different from the tungsten-containing precursor in (b).

16 . An apparatus for processing substrates, the apparatus comprising:
(a) at least one process chamber comprising a pedestal configured to hold a substrate; (b) at least one outlet for coupling to a vacuum; (c) one or more process gas inlets coupled to one or more process gas sources; and (d) a controller for controlling operations in the apparatus, comprising machine-readable instructions for:
(i) introducing a reducing agent and a tungsten-containing precursor in alternating pulses to the process chamber; and
(ii) introducing hydrogen and a tungsten-containing precursor in alternating pulses to the process chamber,
wherein the chamber pressure during (i) is no more than 10 Torr.

17 . (canceled)

18 . (canceled)

Assignees

• Lam Res Corp

Inventors

• Ba Xiaolan
• Humayun Raashina
• Danek Michal
• Schloss Lawrence

Classifications

• H10P14/432

  using selective deposition · CPC title

• H10W20/056

  by filling conductive material into holes, grooves or trenches · CPC title

• H10W20/045

  for deposition from the gaseous phase, e.g. for chemical vapour deposition [CVD] · CPC title

• H10P14/43 Primary

  Chemical deposition, e.g. chemical vapour deposition [CVD] · CPC title

• H01L21/76877

  Electricity · mapped topic