Low-K dielectric gapfill by flowable deposition

Patent metadata

Field	Value
Publication number	US-9412581-B2
Application number	US-201414333262-A
Country	US
Kind code	B2
Filing date	Jul 16, 2014
Priority date	Jul 16, 2014
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

Methods are described for forming a flowable low-k dielectric layer on a patterned substrate. The film may be a silicon-carbon-oxygen (Si—C—O) layer in which the silicon and carbon constituents come from a silicon and carbon containing precursor while the oxygen may come from an oxygen-containing precursor activated in a remote plasma region. A similarly deposited silicon oxide layer may be deposited first to improve the gapfill capabilities. Alternatively, or in combination, the flow of a silicon-and-carbon-containing precursor may be reduced during deposition to change the properties from low-k to high strength roughly following the filling of features of the patterned substrate.

First claim

The invention claimed is:

1. A method of filling a trench, the method comprising:
transferring a patterned substrate comprising the trench into a substrate processing region of a substrate processing chamber;
flowing an oxygen-containing precursor into a remote plasma region while igniting a remote plasma to form a radical-oxygen precursor;
flowing the radical oxygen precursor into the substrate processing region;
flowing a first silicon-and-carbon-containing precursor into the substrate processing region without first passing the first silicon-and-carbon-containing precursor through a plasma, wherein the first silicon-and-carbon-containing precursor has a Si—O:Si ratio of less than 3;
flowing a second silicon-and-carbon-containing precursor into the substrate processing region without first passing the second silicon-and-carbon-containing precursor through a plasma, wherein the second silicon-and-carbon-containing precursor has a Si—O: Si ratio of greater than 2;
combining the first silicon-and-carbon-containing precursor, the second silicon-and-carbon-containing precursor and the radical oxygen precursor in the substrate processing region to form a low-k dielectric layer on the patterned substrate, wherein a portion of the low-k dielectric layer deposits on the substrate and flows along the surface during formation of the low-k dielectric layer to fill the trench, and wherein a partial pressure ratio of the first silicon-and-carbon-containing precursor to the second silicon-and-carbon-containing precursor within the substrate processing region is reduced during formation of the low-k dielectric layer, wherein a second partial pressure ratio of the first silicon-and-carbon-containing precursor to the second silicon-and-carbon-containing precursor measured in the substrate processing region at the end of the formation of the low-k dielectric layer is less than a first partial pressure ratio at the beginning of the formation of the low-k dielectric layer by at least 25%; and
solidifying the low-k dielectric layer within the trench.

2. The method of claim 1 , wherein the low-k dielectric layer has a dielectric constant of between 2.2 and 3.0 following solidification.

3. The method of claim 1 , wherein a temperature of the substrate during formation of the low-k dielectric layer is less than 150° C.

4. The method of claim 1 , wherein the first silicon-and-carbon-containing precursor is octamethylcyclotetrasiloxane or tetramethylcyclotetrasiloxane.

5. The method of claim 1 , wherein the first silicon-and-carbon-containing precursor has a Si—O:Si ratio of 1.

6. The method of claim 1 , wherein the second silicon-and-carbon-containing precursor has a Si—O:Si ratio of 4.

7. The method of claim 1 , wherein the second silicon-and-carbon-containing precursor is tetramethyl orthosilicate.

Assignees

• Applied Materials Inc

Inventors

• Thadani Kiran V
• Liang Jingmei
• Lee Young S
• Srinivasan Mukund

Classifications

• 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

• H10P14/6336

  in the presence of a plasma [PECVD] · CPC title

• H10P14/6334

  using decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition (deposition by physical ablation of a target H10P14/6329) · CPC title

• H10P14/6922 Primary

  the material containing Si, O and at least one of H, N, C, F or other non-metal elements, e.g. SiOC, SiOC:H or SiONC · CPC title

• H01L21/02271

  Electricity · mapped topic