Leveling Plate Spacing Adjustment Mechanism for CVD Uniformity
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Solution Overview
Problem
Conventional semiconductor manufacturing processes face challenges in achieving uniform thickness of layers formed on substrates due to sensitivity in gas flow and deposition rate, which is affected by the spacing between the substrate support and the gas distribution faceplate.
Innovation Solution
A device and method for adjusting the spacing between the substrate support and the gas distribution faceplate using a mounting stud, adjustment screw, and bushing mechanism, allowing for precise control of the gap to optimize gas flow and layer uniformity, incorporating coarse and fine adjustment capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the spacing between the substrate support and the faceplate is decreased to increase film deposition rate, then the deposition rate increases, but the film thickness uniformity becomes more sensitive to spacing uniformity
Solution Approach 1:
The substrate support is made adjustable in spacing relative to the faceplate, transitioning from a fixed to a dynamic configuration. The leveling mechanism with threaded studs and adjustment nuts allows the substrate support position to be precisely modified, enabling optimization of both deposition rate and uniformity based on process requirements
Solution Approach 2:
The spacing parameter between the substrate support and faceplate is made variable through the leveling mechanism. By changing this critical parameter, the system can optimize film deposition characteristics, allowing operators to adjust spacing to achieve desired balance between deposition rate and thickness uniformity
2Productivity
If the substrate is placed very close to the faceplate to increase film deposition rate, then the deposition rate increases, but the sensitivity to spacing uniformity increases
Solution Approach 1:
The substrate support spacing is made dynamically adjustable rather than fixed, allowing the system to adapt to different process conditions. The leveling mechanism enables precise control of substrate position, providing stability and repeatability even when operating at small spacings for high deposition rates
Solution Approach 2:
The leveling mechanism provides a means to measure and correct spacing variations, creating a feedback loop that maintains process stability. By allowing adjustment based on observed uniformity issues, the system can compensate for variations and maintain reliable operation at optimized spacing
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 solution enables improved uniformity of layer thickness by correlating deposition rate with spacing adjustments, demonstrated through experimental results showing reduced thickness variations and enhanced deposition rate control.
Implementation Method 1
An adjustment screw has a first threaded surface threadingly engaged with the stud threaded surface of the mounting stud, and a second threaded surface threadingly engaged with the bushing threaded surface of the bushing
Implementation Method 2
Some substrate heaters are resistively heated, for example, by electrical heating elements such as resistive coils disposed below the heater surface or embedded in a plate having the heater surface
Implementation Method 3
Plasma enhanced CVD processes promote the excitation and/or dissociation of the reactant gases by the application of radio frequency (RF) energy to the reaction zone proximate the substrate surface thereby creating a plasma of highly reactive species
Implementation Method 4
Conventional thermal CVD processes supply reactive gases to the substrate surface where heat-induced chemical reactions can take place to produce the desired film
Data Source
AI summary
A device for adjusting a spacing between a chamber body such as a chamber body and a leveling plate such as a leveling plate comprises a mounting stud configured to be mounted to the chamber body. The mounting stud includes a stud threaded surface. A bushing is capable of being fixed to the leveling plate, and includes a bushing threaded surface. An adjustment screw has a first threaded surface threadingly engaged with the stud threaded surface of the mounting stud, and a second threaded surface threadingly engaged with the bushing threaded surface of the bushing. The threaded surfaces are configured, when the bushing is fixed to the leveling plate and the adjustment screw is turned, to cause the adjustment screw to move in a first direction with respect to the mounting stud at a first rate and the bushing to move in a second direction opposite from the first direction with respect to the adjustment screw at a second rate which is different from the first rate.