MOCVD Facing Member Asperities Prevent Byproduct Contamination
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Solution Overview
Problem
In the metal organic chemical vapor deposition (MOCVD) method for manufacturing compound semiconductors, reaction byproducts adhere to the inner walls of the reaction chamber and can peel off, leading to a decrease in yield due to contamination of the substrate and epitaxially grown films.
Innovation Solution
A compound semiconductor manufacturing device and method featuring a facing member with a facing surface having asperities, including a continuous groove radiating from a central through hole, to prevent reaction byproducts from adhering and peeling off, thereby reducing contamination and increasing yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a smooth facing member is used in the MOCVD apparatus, then the structure is simple and easy to manufacture, but reaction byproducts easily adhere and peel off, causing contamination and yield decrease
Solution Approach 1:
The facing member surface is designed with local quality variation through asperities (protrusions and recesses). These surface irregularities create specific local regions that prevent reaction byproduct adhesion, while other regions maintain smooth surfaces for proper gas flow and epitaxial growth. This localized surface modification resolves the contradiction by making the facing member structure complex only where necessary to prevent byproduct peeling.
2Reliability
If the facing member surface is modified with asperities to prevent byproduct adhesion, then yield improves, but manufacturing complexity increases
Solution Approach 1:
The facing member surface parameters are changed by introducing asperities with specific height, width, and distribution patterns. This parameter modification transforms the smooth surface into an asperity-rich surface that prevents reaction byproduct adhesion. The manufacturing complexity increases only to the extent required to create these controlled surface parameters, which can be achieved through various fabrication techniques such as etching, coating, or direct成型.
3Reliability
If reaction byproducts are allowed to deposit on the inner wall, then the facing member remains clean, but peeled-off byproducts contaminate the substrate and reduce yield
Solution Approach 1:
The facing member surface is pre-modified with asperities before the epitaxial growth process begins. This preliminary surface preparation ensures that when reaction byproducts are generated during the MOCVD process, they will not adhere strongly to the facing member surface and subsequently peel off to contaminate the substrate. The asperities create a surface morphology that prevents strong adhesion from the outset, eliminating the harmful peeling effect.
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 suppresses the adhesion of peeled-off reaction byproducts to the substrate or epitaxially grown film, enhancing the yield of semiconductor devices by ensuring a cleaner growth surface and reducing the need for substrate discarding.
Implementation Method 1
a facing member placed above the formed body, the facing member having a facing surface having asperities formed thereon, the facing surface facing the formed surface
Implementation Method 2
the materials are pyrolyzed around a substrate heated in the reaction chamber, and a compound semiconductor crystal is epitaxially grown on the substrate
Implementation Method 3
a compound semiconductor crystal is epitaxially grown on the substrate
Implementation Method 4
a reaction byproduct (for example, a compound semiconductor) produced in the reaction chamber by a reaction of a material gas adheres or deposits on the inner wall and the like of the reaction chamber
Data Source
AI summary
When compound semiconductor layers are formed on a compound semiconductor substrate (40) by sequentially layering group III nitride semiconductor crystalline layers by metal organic chemical vapor deposition method, the compound semiconductor substrate (40) is attached inside of a reaction container with the crystal growth surface thereof facing upward, a protection member (60) having plural grooves (63) formed in a radiating manner on the side facing the crystal growth surface is attached above the compound semiconductor substrate (40), and a material gas is supplied to the inside of the reaction container through a first through hole (61) provided in the center of the protection member (60). Thereby, in the manufacture of a compound semiconductor using metal organic chemical vapor deposition method, a decrease in yield caused by adhesion of peeled-off reaction byproducts to the substrate or to the epitaxially grown film on the substrate is suppressed.