TiN Barrier Film Deposition Using SiH4 to Suppress HCl Adsorption

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Solution Overview

Problem

The formation of a TiN film as a barrier film in semiconductor manufacturing is hindered by the adsorption of hydrochloric acid (HCl) byproducts generated during the film-forming process, which reduces the deposition rate.

Innovation Solution

A method involving the sequential supply of a metal-containing gas (TiCl4) and a reducing gas (SiH4) within a specific pressure range, followed by removal of residual gases and introduction of a nitrogen-containing gas (NH3) to form a TiN film substantially free of silicon atoms, thereby mitigating the inhibiting effects of HCl.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If TiCl4 gas and NH3 gas are used to form TiN film, then the barrier film function is achieved, but HCl byproduct is generated which adsorbs on the TiN film surface and reduces deposition rate

Engineering Contradiction:

Improvedeposition rateVSAvoidHCl byproduct adsorption

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful HCl byproduct into a beneficial effect by introducing SiH4 gas that reacts with HCl to form volatile SiCl4, which is then removed by exhaust. This transforms the harmful adsorption effect into a useful reaction that eliminates the byproduct and actually enhances deposition rate.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces SiH4 gas as an intermediary substance that mediates between the HCl byproduct and the deposition process. The SiH4 reacts with HCl to form SiCl4, acting as a intermediate reaction step that removes the harmful HCl while maintaining the TiN deposition process.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If SiH4 gas is supplied to reduce HCl, then deposition rate is enhanced, but silicon atoms may be incorporated into the TiN film

Engineering Contradiction:

Improvedeposition rateVSAvoidsilicon content control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent precisely controls the pressure parameter (130 Pa to less than 3,990 Pa) and the timing of gas supply to ensure SiH4 reacts with HCl in the gas phase rather than incorporating Si into the film. By changing and controlling the pressure parameter, the reaction pathway is directed toward forming volatile SiCl4 that can be exhausted, preventing Si incorporation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses periodic gas supply sequences where TiCl4 and SiH4 are supplied in specific time intervals, followed by NH3 supply and exhaust phases. This periodic action ensures that SiH4 is present to react with HCl during the TiCl4 supply phase, then removed before Si incorporation can occur during TiN formation.

Inventive Principle:

Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances the deposition rate and ensures the formation of a high-quality TiN film with minimal silicon content, improving the adhesion and preventing fluorine diffusion in semiconductor devices.

Implementation Method 1

supplying a metal-containing gas and a reducing gas, which contains silicon and hydrogen and does not contain a halogen... (a) includes a timing of simultaneously supplying the metal-containing gas and the reducing gas

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

removing the metal-containing gas and the reducing gas that remain in the process chamber

Methodology Applied

Scientific EffectVacuum evacuation: Vacuum

Implementation Method 3

supplying a nitrogen-containing gas to the substrate... forms a metal nitride film substantially not containing a silicon atom on a substrate

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Data Source

PatentUS20260033256A1Method of manufacturing semiconductor device, substrate processing apparatus, and recording medium

Publication Date: 2026.01.29 KOKUSAI DENKI KK

AI summary

There is provided a method of manufacturing a semiconductor device, including forming a metal nitride film substantially not containing a silicon atom on a substrate by sequentially repeating: (a) supplying a metal-containing gas and a reducing gas, which contains silicon and hydrogen and does not contain a halogen, to the substrate in a process chamber by setting an internal pressure of the process chamber to a value which falls within a range of 130 Pa to less than 3,990 Pa during at least the supply of the reducing gas, wherein (a) includes a timing of simultaneously supplying the metal-containing gas and the reducing gas; (b) removing the metal-containing gas and the reducing gas that remain in the process chamber; (c) supplying a nitrogen-containing gas to the substrate; and (d) removing the nitrogen-containing gas remaining in the process chamber.