# US 7,608,300 B2 · Methods and devices to reduce defects in dielectric stack structures

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- Number: US 7,608,300 B2
- Document ID: US7608300B2
- Status: Granted
- Kind: B2
- Application number: 10/650,941
- Filed: 2003-08-27
- Published: 2005-03-03
- Granted: 2009-10-27
- Earliest claimed: 2003-08-27
- Assignees: Applied Materials, Inc.
- Inventors: Christopher Dennis Bencher; Lee Luo
- Web page: https://patentgrep.com/patent/US7608300B2

## CPC

- C23C 16/4401: {Means for minimising impurities, e.g. dust, moisture or residual gas, in the reaction chamber}
- C23C 16/0245: {by etching with a plasma}
- C23C 16/56: After-treatment
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)

## Abstract

A variety of techniques may be employed alone or in combination to reduce the incidence of defects arising in dielectric stack structures formed by chemical vapor deposition (CVD). Incidence of a first defect type attributable to reaction between an unreacted species of a prior CVD step and reactants of a subsequent CVD step, is reduced by exposing a freshly-deposited dielectric layer to a plasma before any additional layers are deposited. Incidence of a second defect type attributable to the presence of incompletely vaporized CVD liquid precursor material, is reduced by exposing the freshly-deposited dielectric layer to a plasma, and/or by continuing the flow of carrier gas through an injection valve for a period beyond the conclusion of the CVD step.

## Claims

### Claim 1

A method of reducing incidences of defects in a stack of dielectric layers formed by chemical vapor deposition, the method comprising:
flowing a liquid silicon-and-oxygen-containing precursor material to an injection valve;
vaporizing the liquid silicon-and-oxygen-containing precursor material in a carrier gas flowed through the injection valve;
causing a reaction involving the vaporized liquid silicon-and-oxygen-containing precursor material to deposit a first dielectric layer;
halting the flow of liquid silicon-and-oxygen-containing precursor material to the injection valve at a first time while maintaining a flow of the carrier gas to the injection valve; and
halting the flow of carrier gas to the injection valve at a second time after the first time,
wherein a delay between halting of the flow of liquid silicon-and-oxygen-containing precursor material to the injection valve and halting the flow of carrier gas to the injection valve vaporizes the liquid silicon-and-oxygen-containing precursor material remaining in the injection valve and reduces incidences of defects in the stack of dielectric layers caused by subsequent deposition of liquid silicon-and-oxygen-containing precursor material.

### Claim 2 (depends on 1)

The method of claim 1 wherein the flow of liquid silicon-and-oxygen-containing precursor material to the injection valve is halted between about 1-10 seconds before the flow of carrier gas to the injection valve is halted.

### Claim 3 (depends on 1)

The method of claim 1 wherein a delay between the first time and the second time is a result of a software instruction.

### Claim 4 (depends on 1)

The method of claim 1 wherein a delay between the first time and the second time is a result of physical operation of at least one of a valve and a mass flow controller.

### Claim 5 (depends on 1)

The method of claim 1 wherein flowing the liquid silicon-and-oxygen-containing precursor material comprises flowing a liquid precursor material selected from the group consisting of tetraethyl orthosilicate (TEOS), tetramethylcyclotetrasiloxane (TOMCATS), octamethylcyclotetrasiloxane (OMCTS), and dimethyldimethoxysilane (Z2DM).

### Claim 6 (depends on 1)

The method of claim 1 wherein flowing the carrier gas comprises flowing a carrier gas selected from the group consisting of nitrogen, helium, argon, N2O, and combinations thereof.