Ta Sputtering Target Stabilizing Deposition Speed
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Solution Overview
Problem
The deposition speed during sputtering with Ta targets is not constant throughout their life, leading to inefficiencies and increased costs due to the need for mid-process adjustments or premature target replacement, which affects semiconductor production.
Innovation Solution
A Ta or Ta alloy sputtering target with controlled X-ray intensity ratios of the {110} plane, specifically limiting the ratio to 0.4 or less on the surface and at various depths, achieved through degassing heat treatment and controlled plane orientation, to stabilize deposition speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional Ta targets are used during sputtering, then the deposition process can proceed, but the deposition speed fluctuates significantly throughout the target life requiring mid-process adjustments or premature replacement
Solution Approach 1:
The invention changes the crystallographic parameter (plane orientation) of the Ta target by controlling the X-ray intensity ratio of the {110} plane to be 0.4 or less. This parameter change in the target material's crystal structure stabilizes the deposition speed throughout the target life, eliminating the need for mid-process adjustments and maintaining high production efficiency.
2Manufacturing precision
If the sputtering time program is re-programmed midway during target life to compensate for deposition speed variation, then deposition uniformity can be maintained, but production efficiency is significantly inhibited
Solution Approach 1:
The invention performs preliminary action by controlling the plane orientation of the Ta target before the sputtering process begins. By ensuring the X-ray intensity ratio of the {110} plane is 0.4 or less in the target material, the deposition speed is pre-stabilized, eliminating the need for mid-process re-programming and maintaining both precision and productivity.
3Reliability
If Ta targets are replaced ahead of time to maintain deposition speed, then deposition stability is improved, but manufacturing cost is considerably increased
Solution Approach 1:
The invention changes the material parameter (plane orientation) of the Ta target to stabilize deposition speed throughout the entire target life. This allows the target to be used until its actual end of life without premature replacement, reducing material cost while maintaining deposition stability.
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 minimizes deposition speed fluctuations, enhancing production efficiency and reducing costs by maintaining stable deposition speeds throughout the target's life, allowing for functional control of the deposition process.
Implementation Method 1
The speed of forming a thin film on a wafer or a substrate during sputtering is not constant, and changes with the advancement of the erosion of the target.
Implementation Method 2
the ratio of X-ray intensity of (110) measured with X-ray diffraction is 0.4 or less in a Ta or Ta alloy target
Data Source
AI summary
Provided is a sputtering target in which the ratio of X-ray intensity of (110) measured with X-ray diffraction is 0.4 or less, and even 0.2 or less in a Ta or Ta alloy target. Further provided is a sputtering target in which the ratio of X-ray intensity of (110) on a Ta or Ta alloy target surface measured with X-ray diffraction is 0.8 or less, and the ratio of the foregoing X-ray intensity at a depth of 100 μm or deeper is 0.4 or less. This Ta or Ta alloy target is capable of minimizing the fluctuation of the deposition speed for each target throughout the target life of a sputtering target, and thereby improving and stabilizing the production efficiency of semiconductors during the sputtering process, and contributing to the reduction of production costs.