SiGe Side-Etching with Hydrogen Plasma Residue Conditioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional side etching methods for silicon germanium layers face issues with non-uniform etching due to residual deposits from reactive ion etching, leading to loading problems where the etching gas is blocked, preventing uniform etching of the SiGe films.
Innovation Solution
The method involves a substrate processing system that includes a plasma processing apparatus to modify residual deposits on the silicon germanium layers using a plasmarized hydrogen gas, followed by side etching with a fluorine-containing gas, specifically using ClF3, to ensure uniform etching by removing and modifying residual deposits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If reactive ion etching is performed on silicon germanium layers, then etching can be achieved, but residual deposits remain on the surface causing non-uniform etching and loading problems
Solution Approach 1:
A plasma treatment step is introduced before the main etching process to modify and remove residual deposits from the silicon germanium layer surface. This preliminary action cleans the surface to ensure uniform etching in the subsequent step, preventing loading problems while maintaining high etching productivity.
2Manufacturing precision
If multiple etching cycles are performed to achieve uniform etching, then etching uniformity improves, but processing time increases and more damage occurs to the layers
Solution Approach 1:
The plasma treatment is performed as a preliminary step before etching to remove surface residuals that cause loading effects. This allows the main etching process to be completed in fewer cycles while achieving uniform etching, thereby reducing total processing time and minimizing cumulative damage to the silicon and silicon germanium layers.
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 effectively improves the uniformity of side etching by removing and modifying residual deposits, reducing loading issues and achieving a more uniform etching amount with fewer etching cycles, while minimizing damage to the silicon and silicon germanium layers.
Implementation Method 1
modifying surfaces of residuals by supplying a plasmarized gas containing hydrogen to the residuals on exposed end surfaces of the silicon germanium layers
Implementation Method 2
performing side-etching on the silicon germanium layers by supplying a fluorine-containing gas to the silicon germanium layers
Data Source
AI summary
An etching method for performing side-etching of silicon germanium layers of a substrate having alternating silicon layers and the silicon germanium layers formed thereon is provided. The method includes modifying surfaces of residuals by supplying a plasmarized gas containing hydrogen to the residuals on exposed end surfaces of the silicon germanium layers, and performing side-etching on the silicon germanium layers by supplying a fluorine-containing gas to the silicon germanium layers.