HEMT Isolation Trench Structure for Gate-Drain Capacitance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-electron-mobility transistors (HEMTs) exhibit high gate to drain capacitance (Cgd) which changes with different voltage applications, leading to electrical and physical isolation challenges.
Innovation Solution
A semiconductor structure is developed with a stack of semiconductor materials, a trench filled with insulator material, and a damaged region extending from the trench bottom to the substrate, creating a high-density crystalline dislocation region for improved isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a trench filled with insulator material is created to improve electrical isolation, then gate to drain capacitance is reduced, but a damaged region extends from the trench bottom to the substrate creating high-density crystalline dislocation
Solution Approach 1:
A liner layer is introduced as an intermediary between the insulator material and the damaged semiconductor region. This liner prevents direct contact and interaction between the insulator and the crystalline dislocation, reducing the harmful effects of the damaged region while maintaining the electrical isolation function of the trench structure
Solution Approach 2:
The high-density crystalline dislocation region, which would normally be harmful, is converted into a beneficial isolation barrier. The damaged region with high dislocation density creates a natural leakage current barrier that enhances the electrical isolation performance of the trench structure
2Reliability
If isolation structures are implemented to prevent leakage current, then electrical isolation is improved, but moisture ingress pathways may still exist affecting device reliability
Solution Approach 1:
The isolation structure is segmented into multiple functional components: the trench structure for electrical isolation, the liner layer for physical sealing, and the damaged region for current blocking. This segmentation allows each component to address specific isolation challenges including both electrical leakage and moisture ingress pathways
3Speed
If HEMTs are designed for high-frequency operation, then performance is improved, but gate to drain capacitance increases causing isolation challenges
Solution Approach 1:
The isolation approach moves from a two-dimensional planar isolation to a three-dimensional trench structure extending vertically through the semiconductor layers. This vertical dimension provides more effective capacitance reduction by creating greater physical separation between gate and drain regions, enabling high-frequency operation with improved electrical isolation
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 structure achieves enhanced electrical and physical isolation by preventing leakage current and moisture ingress, thereby improving the reliability and performance of HEMTs.
Implementation Method 1
a damaged region of the stack of semiconductor materials extending from at least a bottom of the insulator material to the semiconductor substrate
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5B
AI summary
The present disclosure relates to semiconductor structures and, more particularly, to devices with isolation structures and methods of manufacture. The structure includes: a stack of semiconductor materials; a semiconductor substrate under the stack of semiconductor materials; a trench filled with in insulator material; and a damaged region of the stack of semiconductor materials extending from at least a bottom of the insulator material to the semiconductor substrate.