近日，加州大学伯克利分校Sayeef Salahuddin团队揭示负电容克服了氮化镓高电子迁移率晶体管的肖特基栅限制。这一研究成果于2025年7月10日发表在《科学》杂志上。
对于基于量子阱内二维电子气（2DEG）的高电子迁移率晶体管，例如基于AlGaN/GaN异质结构的晶体管，肖特基门的主题是最大化可诱导的电荷量，从而最大化可获得的电流。然而，肖特基栅也导致通过栅电极的泄漏电流非常高。在氮化层和栅极金属之间添加常规介电层可以减少泄漏；但这是以减少漏极电流为代价的。
研究组将HfO2- ZrO2双分子层作为栅极电介质，实现了导通电流的增加和漏电流的减少，这是传统电介质无法实现的。该方法超越了肖特基GaN晶体管的传统限制，为提高基于2DEG的晶体管的性能提供了新的途径。
附：英文原文
Title: Negative capacitance overcomes Schottky-gate limits in GaN high-electron-mobility transistors
Author: Asir Intisar Khan, Jeong-Kyu Kim, Urmita Sikder, Koushik Das, Thomas Rodriguez, Rohith Soman, Srabanti Chowdhury, Sayeef Salahuddin
Issue&Volume: 2025-07-10
Abstract: For high-electron-mobility transistors based on two-dimensional electron gas (2DEG) within a quantum well, such as those based on AlGaN/GaN heterostructure, a Schottky-gate is used to maximize the amount of charge that can be induced and thereby the current that can be achieved. However, the Schottky-gate also leads to very high leakage current through the gate electrode. Adding a conventional dielectric layer between the nitride layers and gate metal can reduce leakage; but this comes at the price of a reduced drain current. Here, we used a ferroic HfO2- ZrO2 bilayer as the gate dielectric and achieved a simultaneous increase in the ON current and decrease in the leakage current, a combination otherwise not attainable with conventional dielectrics. This approach surpasses the conventional limits of Schottky GaN transistors and provides a new pathway to improve performance in transistors based on 2DEG.
DOI: adx6955
Source: https://www.science.org/doi/10.1126/science.adx6955