Plasma Nitride Film Deposition for Low-Impurity Stress Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for manufacturing semiconductor devices face challenges in improving the quality of nitride films formed on substrates and reducing stress generated in these films after the film-forming process.

Innovation Solution

A method involving a cycle of forming layers on a substrate, where a first layer is formed using a source gas containing silicon and a halogen element, modified by a first modification gas containing hydrogen, and further modified by a second modification gas containing nitrogen and hydrogen, with the supply time of the first modification gas set longer than that of the second modification gas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional film-forming process is used to form a nitride film on a substrate, then the film can be formed with basic properties, but the film quality is insufficient and high residual stress remains after the process

Engineering Contradiction:

Improvenitride film qualityVSAvoidresidual stress in nitride film

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The film-forming process is divided into multiple discrete steps with different gas supplies and parameters. Each step (first nitride film formation, second nitride film formation, silicon nitride film formation) has specific duration, temperature, and gas flow conditions that collectively reduce residual stress while maintaining film quality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The process utilizes parameter changes including temperature variations (heating to specific temperatures and cooling), gas flow rate adjustments, and duration control of each step. These parameter changes enable precise control over film properties and stress reduction.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the film-forming process is extended to improve film quality, then impurity concentration can be reduced, but the processing time increases

Engineering Contradiction:

Improveimpurity concentration in nitride filmVSAvoidfilm-forming process time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The process maintains continuous useful action by performing multiple film-forming steps without interrupting the overall process flow. Each step contributes to impurity reduction while the total time is optimized through efficient parameter selection.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The film-forming process is structured as periodic cycles of gas supply and processing. Each cycle includes specific durations for different gas supplies (source gas, first modification gas, second modification gas) that systematically reduce impurities over time.

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 method enhances the quality of the nitride film by reducing impurity concentration and improves stress management by releasing tensile stress during the temperature lowering step, resulting in a film with minimized residual stress.

Implementation Method 1

forming a second layer by modifying the first layer by supplying a first modification gas containing hydrogen free of nitrogen and exited by plasma to the substrate in the process chamber

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 2

forming a third layer by modifying the second layer by supplying a second modification gas containing nitrogen and hydrogen and exited by plasma to the substrate in the process chamber

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 3

releasing tensile stress during the temperature lowering step

Methodology Applied

Scientific EffectThermal expansion and contraction: Thermal Expansion

Data Source

PatentUS12288683B2Method of manufacturing semiconductor device, substrate processing method, non-transitory computer-readable recording medium and substrate processing apparatus

Publication Date: 2025.04.29 KOKUSAI DENKI KK

AI summary

According to one aspect of a technique of the present disclosure, there is provided a method of manufacturing a semiconductor device, including: (A) forming a film containing a predetermined element and nitrogen on a substrate by performing a cycle a predetermined number of times, wherein the cycle includes: (a) forming a first layer by supplying a source gas containing the predetermined element and a halogen element to the substrate heated to a first temperature; (b) forming a second layer by modifying the first layer by supplying a plasma-excited first modification gas containing hydrogen free of nitrogen; and (c) forming a third layer by modifying the second layer by supplying a plasma-excited second modification gas containing nitrogen and hydrogen. A supply time TH of supplying the first modification gas in (b) is set to be longer than a supply time TN of supplying the second modification gas in (c).