Titanium Nitride Recess Filling via Alternating Deposition and Etch
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Solution Overview
Problem
Existing methods struggle to uniformly form metal-containing films, particularly titanium nitride films, in recesses with high aspect ratios, leading to difficulties in achieving good step coverage and throughput.
Innovation Solution
A film forming method involving alternating cycles of titanium tetrabromide (TiBr4) gas and ammonia (NH3) for deposition, followed by plasma etching with TiBr4 and argon (Ar) gas to widen the recess openings, ensuring high-quality titanium nitride film formation with good step coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional film forming methods are used to form metal films in recesses, then film formation can be achieved, but step coverage is poor and filling property is insufficient
Solution Approach 1:
The film formation process is divided into multiple alternating deposition and etching cycles. Each cycle deposits a thin film layer and then removes part of it through etching, gradually building up the film in the recess areas. This segmented approach allows the film to be formed step-by-step, improving step coverage without requiring excessively long processing times.
Solution Approach 2:
The method employs periodic alternation between deposition and etching operations. The deposition step forms titanium nitride film using TiBr4 and NH3 gases, followed by an etching step that removes excess film. This periodic cycling continues until the desired film thickness and coverage are achieved, enabling controlled film formation in high aspect ratio recesses.
2Manufacturing precision
If multiple processing apparatuses are used to achieve high-quality film formation, then film quality improves, but device complexity and costs increase
Solution Approach 1:
A single substrate processing apparatus is designed to perform multiple functions: it can conduct both the deposition process (forming titanium nitride film using TiBr4 and NH3 gases) and the etching process (removing excess film). This multi-functional apparatus eliminates the need for separate deposition and etching equipment, reducing device complexity and costs while maintaining high film quality through precise control of the alternating cycles.
3Manufacturing precision
If long processing times are used to achieve good step coverage, then film uniformity improves, but throughput decreases
Solution Approach 1:
The etching step removes only a controlled portion of the deposited film, not the entire film. By carefully controlling the etching depth to be less than the deposited thickness, the method achieves progressive film buildup in recess areas without requiring excessively long processing times. This partial action approach balances film uniformity with reasonable throughput.
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
The method achieves high-quality titanium nitride films with improved step coverage and throughput by repeatedly forming and etching the film, utilizing a single substrate processing apparatus, thereby enhancing film formation efficiency and reducing costs.
Implementation Method 1
forming a titanium nitride film in a recess formed on a substrate by supplying a film forming gas containing a metal-containing gas to the processing chamber
Implementation Method 2
etching the titanium nitride film by supplying an etching gas containing a metal-containing gas to the processing chamber
Data Source
AI summary
A film forming method includes (a) preparing a substrate in a processing chamber, (b) forming a titanium nitride film in a recess formed on the substrate by supplying a film forming gas containing a metal-containing gas to the processing chamber, (c) etching the titanium nitride film by supplying an etching gas containing a metal-containing gas to the processing chamber, and (d) repeatedly performing (b) and (c) in this order. The metal-containing gas in (b) is TiBr4 gas or TiCl4 gas. The metal-containing gas in (c) is TiBr4 gas.