Crystalline Interlayer Passivation for III-V Semiconductor Interface States
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Solution Overview
Problem
III-V compound semiconductors used in MOSFETs and other semiconductor devices suffer from a high density of interface states between the III-V compound semiconductor material layer and a high k dielectric material layer, which compromises the crystallinity and mobility of the channel region.
Innovation Solution
A thin crystalline interlayer is formed on the surface of a single crystal III-V compound semiconductor material layer to act as a passivation layer, reducing and eliminating the density of interface states by protecting the crystallinity of the III-V compound semiconductor material layer before further processing, and a high k dielectric material layer is then formed on top of this interlayer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a high k dielectric material layer is formed directly on the III-V compound semiconductor material layer, then the device structure is simplified, but the density of interface states increases significantly
Solution Approach 1:
A crystalline interlayer is introduced as an intermediary between the III-V compound semiconductor material layer and the high k dielectric material layer. This interlayer acts as a mediator that prevents direct interaction between the dielectric material and the semiconductor surface, thereby eliminating the formation of interface states while maintaining structural simplicity.
2Reliability
If chemical pre-treatment or amorphous Si passivation is applied to the III-V compound semiconductor surface, then some interface state reduction is achieved, but the density of interface states remains above 1E12/cm2ev
Solution Approach 1:
The patent changes the physical and chemical parameters of the passivation layer by using a crystalline material instead of amorphous Si, and by controlling the deposition process to maintain crystalline structure. This parameter change enables the passivation layer to preserve the crystallinity of underlying surface atoms while achieving superior interface state reduction below 1E12/cm2ev.
Data Source
AI summary
The present disclosure reduces and, in some instances, eliminates the density of interface states in III-V compound semiconductor materials by providing a thin crystalline interlayer onto an upper surface of a single crystal III-V compound semiconductor material layer to protect the crystallinity of the single crystal III-V compound semiconductor material layer's surface atoms prior to further processing of the structure.