Titanium Nitride Barrier Film Deposition for Flat Tungsten Filling
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Solution Overview
Problem
The challenge in manufacturing semiconductor devices is forming a tungsten film with low resistance, where the embedding width of the groove is small, making it difficult to achieve a flat barrier film, which in turn affects the film's volume and resistance.
Innovation Solution
A technique involving multiple cycles of gas supply in a substrate processing apparatus, where a first layer is formed by sequentially supplying a first element-containing gas, a reducing gas, and a silicon-containing gas, followed by a second layer formed using a second element-containing gas and another reducing gas, to create a titanium nitride film with improved flatness and density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a titanium nitride film is formed as a barrier film between tungsten film and insulating film, then adhesion between tungsten film and insulating film is improved, but the film surface becomes non-flat, causing volume decrease of tungsten film and increased resistance
Solution Approach 1:
The film formation process is divided into multiple cycles, each cycle forming a portion of the titanium nitride film. This segmentation allows for better control of film growth and surface flatness while maintaining adhesion properties.
Solution Approach 2:
The patent employs periodic cycling of gas supply (first element-containing gas, reducing gas, and silicon-containing gas) to form the titanium nitride film in repeated cycles. This periodic action enables precise control over film deposition, ensuring both adhesion and flatness are achieved.
2Productivity
If the embedding width of the groove is small, then device integration is improved, but it becomes difficult to form a flat barrier film, affecting tungsten film volume and resistance
Solution Approach 1:
The patent changes process parameters including gas supply sequences, temperatures, and pressure conditions during film formation. By optimizing these parameters, the method achieves flat barrier films even in narrow grooves with small embedding widths, thereby maintaining both device integration and manufacturing precision.
3Manufacturing precision
If multiple gas supply cycles are performed to form titanium nitride film, then film flatness and density are improved, but process time increases
Solution Approach 1:
The patent maintains continuous film formation through sequential gas supply without interrupting the deposition process. By continuously supplying different gases in a coordinated manner, the titanium nitride film is formed with high flatness and density while minimizing idle time between cycles.
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 enables the formation of a flat and high-density titanium nitride film, which enhances the adhesion and reduces the resistivity of the tungsten film formed on it, addressing the issue of small groove widths and resistance.
Implementation Method 1
supplying a first reducing gas to the substrate non-simultaneously with (a1)
Implementation Method 2
supplying a first silicon-containing gas to the substrate
Implementation Method 3
supplying a second reducing gas to the substrate
Data Source
AI summary
Described herein is a technique capable of forming a flat film. According to one or more embodiments of the present disclosure, there is provided a technique that includes: (a) forming a first layer containing silicon on a substrate by performing a first cycle once or more, wherein the first cycle includes: (a1) supplying a first element-containing gas containing a first element other than silicon to the substrate; (a2) supplying a first reducing gas to the substrate non-simultaneously with (a1); and (a3) supplying a first silicon-containing gas to the substrate; and (b) forming a second layer on the first layer by performing a second cycle once or more after (a), wherein the second cycle comprises: (b1) supplying a second element-containing gas to the substrate; and (b2) supplying a second reducing gas to the substrate.