Fundamental understanding and development of novel high dielectric constant ALD gate oxides on gallium nitride substrates for MOSFET power conversion applications

用于 MOSFET 功率转换应用的氮化镓衬底上新型高介电常数 ALD 栅极氧化物的基本理解和开发

• 批准号: 355520-2012
• 负责人: Cadien, Kenneth
• 金额: $ 1.75万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=549751
• 关键词: Fundamental; understanding; development; novel; dielectric

Gallium Nitride (GaN) is one of the best candidates for high-temperature, high-power, and high-frequency metal-oxide-semiconductor field-effect transistors (MOSFETs). Power devices made with GaN have the potential to offer a switching speed with a figure of merit more than 500 times greater than that achievable in silicon. The critical component to enable this technology is the development of a robust oxide with low defects and preferential mobility properties that can produce an enhancement mode transistor rather than a depletion mode transistor. However, gate leakage current through the gate oxide and Fermi-level pinning due to large number of interface states at dielectric/GaN interface limit their usage in such applications. Currently, no single material has the ability to cover all the oxide requirements for GaN. Moreover, the oxides must fulfill various requirements such as a large band gap to increase the breakdown voltage. The long term objective of the proposed research program is to develop novel gate oxides for GaN high power MOSFET devices for power conversion applications such as hybrid cars and solar cell arrays. The long term research will take place in collaboration with Professor Douglas Barlage, a device physicist and expert in GaN technology, in Electrical and Computer Engineering at the University of Alberta. The shorter term objectives are to develop a fundamental understanding of the atomic layer deposition (ALD) growth of gate oxides on GaN, and to develop novel GaN gate oxides and structures. The main focus will be to investigate the combinations of high-k metal oxides in the form of nanolaminates to introduce all the required properties, such as large bandgap materials and large dielectric constant, to the gate material of GaN MOS structure. The oxides will be deposited by ALD to benefit from the many advantages of this technique, including excellent control on thickness, deposition at low temperatures, pinhole-free, and highly conformal thin films. The effect of chemistry, microstructure, and stoichiometry of these oxides on the electrical properties of atomic layer deposited films will be explored.

氮化镓(GaN)是制作高温、大功率、高频金属氧化物半导体场效应晶体管(MOSFET)的最佳候选材料之一。由GaN制成的功率器件具有提供开关速度的潜力，其优值系数比在硅中实现的要大500倍以上。实现这一技术的关键部件是开发一种具有低缺陷和优先迁移率特性的坚固氧化物，该氧化物可以制造增强型晶体管而不是耗尽型晶体管。然而，由于介质/GaN界面的大量界面态，通过栅氧化层的栅漏电流和费米能级钉扎限制了它们在此类应用中的应用。目前，没有一种单一的材料能够覆盖GaN的所有氧化物要求。此外，氧化物必须满足各种要求，如大带隙以增加击穿电压。提出的研究计划的长期目标是开发用于混合动力汽车和太阳能电池阵列等功率转换应用的GaN大功率MOSFET器件的新型栅氧化物。这项长期研究将与阿尔伯塔大学电气和计算机工程专业的设备物理学家、GaN技术专家道格拉斯·巴拉奇教授合作进行。较短期的目标是对GaN上栅氧化物的原子层沉积(ALD)生长有一个基本的了解，并开发新型的GaN栅氧化物和结构。主要的焦点将是研究以纳米层状形式存在的高k金属氧化物的组合，以将所有所需的特性，如大禁带材料和高介电常数，引入到GaN MOS结构的栅材料中。氧化物将由ALD沉积，以受益于该技术的许多优点，包括出色的厚度控制、低温沉积、无针孔和高度共形薄膜。我们将探讨这些氧化物的化学、微结构和化学计量比对原子层沉积薄膜电学性能的影响。