Shower Head Compensation Plate for Plasma Density Uniformity
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Solution Overview
Problem
Current plasma processing technologies face challenges in achieving uniform plasma density distribution across substrates during etching processes, leading to non-uniform etch rates and potential failures.
Innovation Solution
A shower head assembly with a compensation plate featuring first and second gas passages of different lengths, integrated into a plasma processing apparatus, which adjusts gas velocities and plasma density profiles to ensure uniform etch rates across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional shower head with uniform gas passages is used, then the structure is simple, but the plasma density distribution is non-uniform across the substrate
Solution Approach 1:
The compensation plate implements local quality by providing different gas passage lengths in different regions. The first region has gas passages of a first length while the second region has gas passages of a second length greater than the first length. This creates locally differentiated gas flow characteristics to compensate for radial plasma density non-uniformity, achieving uniform plasma density across the substrate without requiring a completely complex redesign of the shower head structure.
2Manufacturing precision
If gas passages of different lengths are introduced to compensate plasma density, then plasma uniformity is improved, but the device complexity increases
Solution Approach 1:
The compensation plate is segmented into a first region and a second region, each with gas passages of different lengths. This segmentation allows independent optimization of gas flow characteristics in different radial zones of the substrate, enabling precise control over plasma density distribution and etch rate uniformity while keeping the overall structure manageable through clear regional division.
3Manufacturing precision
If the shower head structure is modified to achieve uniform plasma density, then etch rate uniformity is improved, but the manufacturing complexity increases
Solution Approach 1:
A compensation plate is introduced as an intermediary component between the gas supply system and the substrate. This separate plate can be manufactured independently with the required different-length gas passages, then assembled to the existing shower head structure. This approach achieves uniform plasma density distribution while minimizing the impact on overall manufacturing complexity, as the compensation plate can be produced using standard fabrication techniques.
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 achieves a uniform plasma density distribution and etch rate across the substrate, enhancing the reliability and efficiency of the etching process.
Implementation Method 1
a compensation plate on a lower surface of the shower plate and facing the substrate, the compensation plate including a first compensating portion having first gas passages of a first length and a second compensating portion having second gas passages of a second length that is greater than the first length, wherein the first gas passage and the second gas passage are respectively in fluid communication with the injection holes
Implementation Method 2
a power supply to apply a power to the lower electrode to generate plasma within the chamber
Implementation Method 3
applying a plasma power to the lower electrode to generate plasma within the chamber
Data Source
AI summary
A shower head assembly for a plasma processing apparatus in which a substrate is accommodatable on a substrate stage within a chamber, a plasma processing apparatus, and a plasma processing method, the shower head assembly including a shower plate including a plurality of injection holes through which a gas is sprayable out toward the substrate; and a compensation plate on a lower surface of the shower plate and facing the substrate, the compensation plate including a first compensating portion having first gas passages of a first length and a second compensating portion having second gas passages of a second length that is greater than the first length, wherein the first gas passage and the second gas passage are respectively in fluid communication with the injection holes.