Rotating Electrostatic Chuck for Uniform Wafer Deposition
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Solution Overview
Problem
In semiconductor wafer processing, rotating wafers during vapor deposition can lead to non-uniform thin film composition and thickness due to centrifugal forces, causing wafers to move and lose symmetry, which affects uniformity.
Innovation Solution
A semiconductor processing apparatus with a circular ceramic susceptor and electrostatic chucks that rotate under a showerhead, using bipolar or multipolar electrostatic chucks to clamp wafers securely and maintain symmetry during deposition, ensuring uniform thin film deposition across wafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wafers are rotated during vapor deposition, then across-wafer uniformity of thin film composition and thickness is improved, but centrifugal forces cause wafers to move and dislodge, degrading uniformity
Solution Approach 1:
The electrostatic chuck applies clamping force to the wafer before rotation begins, securing the wafer in place. This preliminary action prevents the wafer from moving or dislodging when centrifugal forces act on it during rotation, thereby maintaining both wafer position stability and across-wafer thin film uniformity
2Reliability
If electrostatic chucks are used to clamp wafers during rotation, then wafer position stability is improved, but the complexity of the deposition system increases
Solution Approach 1:
The electrostatic chuck serves multiple functions: it clamps the wafer to prevent displacement during rotation, maintains wafer flatness against the susceptor surface, and enables precise positioning. By combining these functions into a single component, the system achieves improved wafer position stability without proportionally increasing overall system complexity
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 solution effectively prevents wafer displacement and maintains uniformity in thin film composition and thickness by securely clamping wafers with electrostatic chucks, even at high temperatures, improving the overall quality of deposited films.
Implementation Method 1
applying first electrostatic voltage signals to a first bipolar electrostatic electrode in the first ceramic electrostatic chuck, and chucking the first semiconductor wafer
Implementation Method 2
depositing a thin film on the first and the second semiconductor wafers when rotating the susceptor. The vapor deposition process includes chemical vapor deposition (CVD) and atomic layer deposition (ALD)
Data Source
AI summary
A semiconductor processing apparatus includes a processing chamber with a showerhead and a circular ceramic susceptor disposed in the processing chamber, the ceramic susceptor being coupled to a central susceptor shaft. The ceramic susceptor includes a wafer pocket, which includes a ceramic electrostatic chuck for supporting a wafer. The ceramic susceptor is configured to rotate the wafer pocket under the showerhead, where the ceramic electrostatic chuck is configured to rotate within the wafer pocket.