Shield Gap Design for Stable Sputtering Pressure
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Solution Overview
Problem
In sputtering apparatuses, adjusting the target-to-substrate distance leads to changes in process gas pressure due to varying gap structures, which complicates the reproducibility of film quality, especially with advancements in micropatterning technologies requiring more precise pressure control.
Innovation Solution
A substrate processing apparatus with a process chamber, exhaust unit, gas introduction unit, and shields configured to maintain a constant minimum gap size between the first and second shields, preventing changes in conductance and pressure when the substrate holder moves, thereby stabilizing the process gas pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the substrate holder is moved to adjust the target-to-substrate distance, then the film quality can be improved or stabilized, but the process gas pressure changes due to varying gap conductance
Solution Approach 1:
A gas flow rate adjustment mechanism is introduced as an intermediary component to compensate for conductance changes in the exhaust path. When the substrate holder moves and changes the gap structure, the gas flow rate adjustment mechanism modifies the gas introduction rate to maintain constant process gas pressure, thereby decoupling the relationship between TS distance adjustment and pressure variation
Solution Approach 2:
A feedback control system is implemented where the gas introduction rate is continuously adjusted based on detected changes in process conditions. When the substrate holder position changes, the system detects the resulting conductance variation and automatically adjusts the gas flow rate to maintain stable pressure, creating a closed-loop control that ensures consistent process gas pressure throughout the deposition process
2Manufacturing precision
If the gap structure between shields is changed to adjust TS distance, then film thickness distribution can be controlled, but the conductance of the exhaust path changes
Solution Approach 1:
The system dynamically changes the gas introduction rate parameter to compensate for conductance changes in the exhaust path. When the gap structure between shields is modified to adjust TS distance, the gas flow rate adjustment mechanism modifies the gas introduction rate to maintain constant process gas pressure, thereby decoupling the relationship between structural changes and pressure variation
Data Source
AI summary
An apparatus includes a process chamber, a substrate holder arranged in the process chamber, a first shield provided on the peripheral portion of the substrate holder, and a second shield provided inside the process chamber. The internal space of the process chamber is partitioned into an outer space and a process space to process the substrate, by at least the first shield, the second shield, and the substrate holder. The substrate holder can be driven along a driving direction perpendicular to a substrate holding surface. The length, in a direction parallel to the driving direction, of a minimum gap portion having a minimum size in a direction perpendicular to the driving direction between the first and second shields does not change even if the substrate holder is driven in the driving direction.