In this paper, we introduce novel surface treatments of UV/Ozone and TMAH to solve the surface problem of gate recess of InAlAs/InGaAs InP-based HEMTs. The problem of nonstoichiometric surface of InP etch stopper layer was found to be the result of donor-like surface defects brought by HF damage, bringing troubles like kink effect, high gate leakage current and deteriorated noise performance. Through the method of surface treatments, the InAlAs/InGaAs InP-based HEMTs exhibit excellent DC performances, demonstrating a low gate leakage currents of 10 −8 A/ $\mu {\mathrm{ m}}$ , a peak transconductance of 1100mS/mm, an improved subthreshold swing of 92.5mV/decade at $\text{V}_{\mathrm{ ds}} = 1.0\text{V}$ , and a positive threshold voltage shift of $\text{V}_{\mathrm{ th}}= 300$ mV. The ft of 260GHz and fmax of 440GHz were hardly influenced by the surface treatments while the noise performances were improved obviously. Two orders of magnitude smaller input noise spectral density shows the method of surface treatment can effectively reduce the surface defects and significantly improve the surface of gate recess of InAlAs/InGaAs InP-based HEMTs.

中文翻译：

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通过UV/臭氧和TMAH处理改善InAlAs/InGaAs InP基HEMT的表面

在本文中，我们介绍了 UV/Ozone 和 TMAH 的新型表面处理，以解决 InAlAs/InGaAs InP 基 HEMT 的栅极凹陷表面问题。研究发现，InP蚀刻终止层表面非化学计量问题是由于HF损伤带来的类施主表面缺陷，带来扭结效应、高栅极漏电流和噪声性能恶化等问题。通过表面处理的方法，InAlAs/InGaAs InP 基 HEMT 表现出优异的直流性能，显示出 10 -8 A/的低栅极漏电流 $\mu {\mathrm{ m}}$ ，峰值跨导为 1100mS/mm，改进的亚阈值摆幅为 92.5mV/decade at $\text{V}_{\mathrm{ ds}} = 1.0\text{V}$ ，以及一个正阈值电压偏移 $\text{V}_{\mathrm{ th}}= 300$ 毫伏。260GHz的ft和440GHz的fmax几乎不受表面处理的影响，噪声性能得到明显改善。两个数量级的输入噪声谱密度表明该表面处理方法可以有效减少表面缺陷并显着改善 InAlAs/InGaAs InP 基 HEMT 的栅极凹槽表面。