Enhancement-Mode Heterojunction Structure With Depolarizing Intermediate Layer
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Solution Overview
Problem
Existing high electron mobility transistors (HEMTs) face challenges in achieving a normally-off state due to low activation efficiency of p-type ions, which leads to reduced control ability of the gate electrode over the channel when thick p-type semiconductor layers are used, compromising device performance.
Innovation Solution
Incorporating an intermediate layer, such as an amorphous or polycrystalline layer, between the channel layer and the potential barrier layer in the heterojunction structure to depolarize the potential barrier layer, ensuring the device is normally off without polarization effect, and enabling strong gate control when activated.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the thickness of the p-type semiconductor layer is increased to provide more hole concentration, then the device can achieve normally-off state, but the control ability of the gate electrode to the channel is reduced
Solution Approach 1:
An intermediate layer is introduced between the channel layer and the first potential barrier layer in the gate region. This intermediate layer depolarizes the contacted first potential barrier layer, enabling the device to be normally off while maintaining strong gate control capability. The intermediate layer acts as a mediator that resolves the contradiction between achieving normally-off state and preserving gate control.
Solution Approach 2:
The invention changes the structural parameters by introducing an intermediate layer with specific thickness (greater than 0.2 nm) and material properties. This parameter change allows the first potential barrier layer to be depolarized, achieving normally-off state without requiring thick p-type semiconductor layers, thus maintaining gate control ability.
2Quantity of substance
If traditional p-type ions are used with low activation efficiency, then high doping concentration is required to achieve p-type semiconductor layer, but self-compensation effect reduces hole concentration
Solution Approach 1:
The intermediate layer serves as an intermediary that depolarizes the first potential barrier layer, eliminating the need for high doping concentrations of traditional p-type ions. This approach avoids the self-compensation effect that occurs with high Mg doping, thereby achieving the desired hole concentration without increasing device complexity.
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 intermediate layer allows the device to be normally off without two-dimensional electron gas formation until activated, maintaining robust gate control over the channel, thus enhancing device performance.
Implementation Method 1
the intermediate layer is adapted to depolarize the contacted first potential barrier layer
Data Source
AI summary
The present disclosure provides an enhancement-type semiconductor structure and a manufacturing method thereof. The enhancement-type semiconductor structure includes: a semiconductor substrate and a heterojunction structure distributed from bottom to top; where the heterojunction structure includes a channel layer close to the semiconductor substrate and a first potential barrier layer far away from the semiconductor substrate; the heterojunction structure includes a gate region, and a source region and a drain region on two sides of the gate region respectively, and an intermediate layer is sandwiched between the channel layer and the first potential barrier layer in the gate region, the intermediate layer is adapted to depolarize the contacted first potential barrier layer.