Dielectric Coated Partition Plate for Uniform Radical Etching
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Solution Overview
Problem
The existing substrate processing methods using radicals for etching semiconductor wafers face challenges in maintaining uniformity due to radical inactivation on the inner walls of the processing chamber, leading to reduced etching rates, especially at the outer peripheral sides of the wafer.
Innovation Solution
A substrate processing apparatus is designed with a partition plate and inner wall surface coated with a dielectric material having a recombination coefficient of 0.002 or less, specifically quartz, to suppress radical inactivation and ensure uniform etching by preventing radicals from adsorbing on the chamber walls until they reach the wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the distance between the wafer and the inner wall of the processing chamber is short, then the etching rate at the outer peripheral side decreases due to radical adsorption, but increasing the distance reduces the chamber volume and increases processing complexity
Solution Approach 1:
The inner wall surface is coated with a dielectric material having low recombination coefficient (0.002 or less) specifically in the region above the mounting table, creating local quality differentiation. This allows radicals to be preserved where needed (near the wafer) while maintaining appropriate chamber dimensions elsewhere.
Solution Approach 2:
The recombination coefficient parameter of the inner wall surface is changed by applying a dielectric material coating. This parameter change reduces radical adsorption from 0.002 or less compared to conventional materials, allowing short distances while maintaining etching uniformity.
2Object-affected harmful factors
If a partition plate is introduced to suppress ion passage, then ion damage to the wafer is reduced, but radical inactivation on the partition plate surface increases
Solution Approach 1:
The partition plate surface is coated with a dielectric material having recombination coefficient of 0.002 or less, changing the surface parameter to reduce radical adsorption. This allows the partition plate to block ions effectively while minimizing radical inactivation at the surface.
Solution Approach 2:
The partition plate is constructed as a composite structure combining the partitioning function with a dielectric material coating layer. This composite approach provides both ion blocking capability and low radical recombination properties.
3Productivity
If radicals are allowed to reach the wafer surface directly, then etching rate increases, but in-plane uniformity deteriorates due to radial distribution effects
Solution Approach 1:
The recombination coefficient parameter of surrounding surfaces is reduced to 0.002 or less, changing the radical transport environment. This allows radicals to maintain activity longer during transport, achieving both high etching rates and improved uniformity through controlled radical distribution.
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 enhances etching uniformity and increases the etching rate across the wafer surface by minimizing radical inactivation, particularly at the outer peripheral sides, thereby improving in-plane uniformity and maintaining the radicals' activity until they reach the substrate.
Implementation Method 1
the radicals are diffused and adsorbed onto the inner wall surface of the processing chamber and the components in the processing chamber, the adsorbed radicals are inactivated
Implementation Method 2
a dielectric material having a recombination coefficient of 0.002 or less
Implementation Method 3
generating a plasma from a gas by a high frequency energy
Implementation Method 4
a high frequency power supply configured to supply the high frequency energy into the processing chamber
Implementation Method 5
a partition plate provided in the processing chamber and configured to divide an inner space of the processing chamber into a plasma generation space and a substrate processing space and suppress passage of ions therethrough
Implementation Method 6
the partition plate and a portion of an inner wall surface of the processing chamber which is positioned at least above the mounting table are covered by a dielectric material having a recombination coefficient of 0.002 or less
Data Source
AI summary
A substrate processing apparatus, for generating a plasma from a gas by a high frequency energy and etching a substrate in a processing chamber by radicals in the plasma, includes a high frequency power supply configured to supply the high frequency energy into the processing chamber, a gas supply source configured to introduce the gas into the processing chamber, a mounting table configured to mount the substrate thereon, and a partition plate provided in the processing chamber and configured to divide an inner space of the processing chamber into a plasma generation space and a substrate processing space and suppress passage of ions therethrough. The partition plate and a portion of an inner wall surface of the processing chamber which is positioned at least above the mounting table are covered by a dielectric material having a recombination coefficient of 0.002 or less.