Semiconductor Recess Pre-Bake for Epitaxial Buffer Layer
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Solution Overview
Problem
The formation of native oxides on the deposition surface of semiconductor recesses hinders the growth of high-quality epitaxial buffer layers, leading to defective semiconductor structures and compromised performance.
Innovation Solution
A pre-bake process with a temperature of 740-840°C and a pressure of equal to or higher than 150 torr is used to effectively remove native oxides from the deposition surface, allowing for the formation of a low-defective epitaxial buffer layer without the need for hydrofluoric acid, thereby improving semiconductor structure performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional epitaxial growth is performed directly on the recess surface, then the process is simple, but native oxides form on the deposition surface leading to defective epitaxial buffer layers
Solution Approach 1:
A pre-bake process is performed before epitaxial growth to remove native oxides from the recess surface. This preliminary action creates an oxide-free deposition surface that enables high-quality epitaxial buffer layer formation without subsequent defects
Solution Approach 2:
The pre-bake process uses specific parameter ranges (temperature: 700-850°C, pressure: 150-600 torr) to effectively remove native oxides. These controlled parameter changes enable selective oxide removal while preserving the recess structure and preparing the surface for epitaxial growth
2Manufacturing precision
If hydrofluoric acid is used to remove native oxides, then oxide removal is effective, but the semiconductor structure is damaged
Solution Approach 1:
The chemical etching method using hydrofluoric acid is replaced with a thermal pre-bake process. This substitution uses heat and controlled atmosphere instead of aggressive chemicals to remove native oxides, achieving the same oxide removal goal without damaging the semiconductor substrate or surrounding structures
Solution Approach 2:
The pre-bake process converts the potentially harmful high-temperature environment into a beneficial treatment that selectively removes native oxides while preparing the surface for epitaxial growth. The controlled atmosphere and temperature regime transform what could be damaging conditions into a useful surface preparation method
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 method significantly reduces the defective percentage of epitaxial buffer layers by 55-80%, enhancing the performance and integrity of semiconductor structures while preventing damage from hydrofluoric acid.
Implementation Method 1
performing a pre-bake process at a temperature of 740-840° C. and under a pressure of equal to or higher than 150 torr
Implementation Method 2
forming an epitaxial buffer layer in the recess
Data Source
AI summary
A manufacturing method of a semiconductor structure is provided. The manufacturing method of the semiconductor structure includes the following steps: providing a substrate; forming a gate structure on the substrate; forming a recess in the substrate at a lateral side of the gate structure; performing a pre-bake process at a temperature of 740-840° C. and under a pressure of equal to or higher than 150 torr; and forming an epitaxial buffer layer in the recess.