Susceptor Support Surface for Wafer Alignment in Vapor Phase Growth
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Solution Overview
Problem
Wafer misalignment during film formation in vapor phase growth apparatuses leads to deteriorated wafer flatness and thickness uniformity of films, particularly when forming SiC films on wafers.
Innovation Solution
The vapor phase growth apparatus incorporates a susceptor with a wafer support portion featuring an inclined surface and recessed portions to enhance frictional contact between the wafer and the support, preventing misalignment and thermal deformation, thereby maintaining film uniformity and flatness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a wafer is placed on a susceptor and a SiC film is formed on the front surface, then film formation is achieved, but wafer misalignment occurs causing deteriorated wafer flatness and thickness uniformity
Solution Approach 1:
The susceptor is designed with an inclined surface and recessed portions that preliminarily constrain the wafer position and orientation before the film formation process begins. The inclined surface prevents rotational movement by creating mechanical interference, while the recessed portions secure the wafer in place, thereby preventing misalignment during the subsequent SiC film formation.
Solution Approach 2:
The inclined surface acts as an intermediary mechanical constraint between the susceptor and the wafer. It provides frictional contact that mediates the interaction, preventing direct sliding or rotational movement of the wafer while allowing the film formation process to proceed without misalignment.
2Ease of manufacture
If the susceptor uses a flat support surface, then manufacturing is simple, but wafer misalignment and thermal deformation occur
Solution Approach 1:
Instead of making the entire susceptor surface complex, the invention applies local quality by providing an inclined surface and recessed portions only at specific locations where the wafer contacts the susceptor. This localized modification prevents misalignment and thermal deformation while keeping the rest of the susceptor structure simple and easy to manufacture.
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 effectively curbs wafer misalignment, improves film thickness uniformity, and maintains wafer flatness by increasing frictional force and stabilizing the wafer during rotation and thermal processing.
Implementation Method 1
The wafer support portion has an inclined surface and a flat portion. The inclined surface is connected to an inner edge of the wafer support portion. The flat portion faces upward. The inclined surface is positioned upward as the inclined surface approaches an outward side of the wafer support portion in a radial direction.
Implementation Method 2
a heating portion that heats the susceptor and the wafer when the wafer is placed on the susceptor
Implementation Method 3
when a film made of SiC or the like is formed on the front surface of a wafer
Data Source
AI summary
A vapor phase growth apparatus according to an embodiment has a susceptor on which a wafer is to be placed. The vapor phase growth apparatus has a drive portion for rotating the susceptor. The susceptor has a wafer support portion. The wafer support portion supports the wafer. The wafer support portion has an annular shape. The wafer support portion has a support surface. The support surface supports the wafer from below. The support surface has an inclined surface and a flat portion. The inclined surface is connected to an inner edge of the wafer support portion. The flat portion faces upward. The inclined surface is positioned upward as the inclined surface approaches an outward side of the wafer support portion in a radial direction. The flat portion is connected to an outer end portion of the inclined surface in the radial direction.