场板抑制GaN高电子迁移率晶体管电流崩塌的机理研究

• 作 者: 毛维 杨翠 郝跃 张进成 刘红侠 马晓华 王冲 张金风 杨林安 许晟瑞 毕志伟 周洲 杨凌 王昊
• 机 构: 西安电子科技大学微电子学院宽禁带半导体材料与器件教育部重点实验室,西安电子科技大学技术物理学院,
• 出 处: 物理学报
• 发表日期: 2011年01期
• 关键词: 场板 GaN 电流 电流崩塌 钝化器件 场板器件 器件 电子浓度 陷阱电离率 陷阱

通过实验和数值器件仿真研究了钝化GaN高电子迁移率晶体管(HEMTs)、栅场板GaNHEMTs和栅源双层场板GaNHEMTs电流崩塌现象的物理机理,建立了电流崩塌强度与帽层中载流子浓度、陷阱电离率和电场的内在联系.研究结果表明,场板可以有效调制帽层中横向和纵向电场的强度分布,并可有效调制纵向电场的方向,减弱栅极附近电场强度,增加场板下方电场强度,这会减弱栅极附近自由电子的横向运动,增强场板下方自由电子的纵向运动,进而可以有效调制帽层中自由电子浓度的分布,提高陷阱的电离率,减小器件的电流崩塌.

The physical mechanism of passivation of GaN HEMTs, GaN HEMTs and gate-source bilayers in GaN HEMTs was investigated by experiments and numerical simulation. The current collapse strength and the current-carrying capacity Ion concentration and trap ionization rate and electric field.The results show that the field plate can effectively modulate the intensity distribution of the horizontal and vertical electric field in the cap layer and can effectively modulate the direction of the vertical electric field and weaken the electric field intensity near the gate, Which will weaken the lateral movement of free electrons in the vicinity of the gate and enhance the longitudinal movement of free electrons under the field plate, so as to effectively modulate the distribution of free electrons in the cap layer, improve the ionization rate of the trap, Current collapse.