HEMT Channel Thickness Layout for Lower On-Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-electron-mobility transistors (HEMTs) face challenges in achieving optimal on-resistance and total output charge due to limitations in channel resistance, particularly in GaN HEMT devices used in high-frequency applications.
Innovation Solution
The design incorporates a channel region with varying thicknesses, featuring a thicker portion remote from the gate structure and a field plate, which increases carrier concentration and reduces channel resistance, along with specific Al concentrations and fabrication methods using integrated circuit technology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the channel region thickness is increased to reduce channel resistance and improve on-resistance, then the on-resistance improves, but the device area and fabrication complexity increase
Solution Approach 1:
The channel region is segmented into multiple portions with different thicknesses: a first portion under the gate structure and a second portion remote from the gate structure. This segmentation allows each portion to be optimized independently, reducing overall device complexity while achieving the desired on-resistance improvement through the thicker second portion.
Solution Approach 2:
Different portions of the channel region are given different thicknesses to optimize local properties. The thicker second portion remote from the gate structure provides lower resistance, while the first portion under the gate maintains appropriate thickness for gate control, achieving local optimization of electrical properties.
2Reliability
If a thicker channel region is used to improve total output charge, then the total output charge increases, but the manufacturing precision requirements increase
Solution Approach 1:
The channel is divided into segments with different thicknesses that can be formed using separate fabrication steps. This segmentation allows each thickness portion to be controlled independently within standard manufacturing tolerances, reducing the overall precision requirements compared to forming a single uniform thick channel.
Solution Approach 2:
The solution transitions from a uniform one-dimensional channel thickness to a multi-dimensional structure with varying thickness in the vertical dimension. This dimensional change allows optimization of total output charge through the thicker second portion while maintaining manufacturability through standard thickness control techniques.
Data Source
AI summary
The present disclosure relates to semiconductor structures and, more particularly, to a high-electron-mobility transistor and methods of manufacture. The structure includes: a gate structure; and a channel region under the gate structure, the channel region having a first portion including a first thickness and a second portion having a second thickness greater than the first thickness, the second portion being positioned remotely from the gate structure.