AlGaN/GaN HEMT结构热时间常数谱提取方法的研究

利用电学法对AlGaN/GaN 高电子迁移率晶体管(HEMTs)有源区瞬态温升进行测量.利用非参数拟合算法—局部加权回归散点平滑法(LOWESS)对原始测量数据进行平滑去噪处理，进而得到热时间常数谱，分析AlGaN/GaN HEMTs热传导路径物理结构。与传统平滑去噪方法—多阶指数拟合相比，通过LOWESS算法得到的热时间常数谱更丰富，得到RC网络更多，进而热传导路径结构分析更精细。结果表明，LOWESS非参数拟合算法能够更好的去除测量数据噪声，保留原始离散数据细微的变化趋势。通过该方法所提取的热时间常数谱能描述AlGaN/GaN HEMTs有源区温度细微变化，帮助研究人员精确分析热传导路径层次构成。

Thermal time-constant spectrum extraction method in AlGaN/GaN HEMTs

The transient temperature rise in the active region in AlGaN/GaN high electron mobility transistors (HEMTs) is measured using an electrical method. The original data are smoothed and denoised by a nonparametric fitting algorithm, called locally weighted scatterplot smoothing (LOWESS). The thermal time-constant spectrum is extracted to analyze the physical structure of the heat-conduction path in AlGaN/GaN HEMTs. The thermal time-constant spectra extracted using the LOWESS algorithm are richer and the RC network obtained is greater compared with those with the traditional denoising method (multi-exponential fitting). Thus, the analysis of the heat-flow path is more precise. The results show that the LOWESS nonparametric fitting algorithm can remove noise from measured data better than other methods and can retain the subtle variation tendency of the original discrete data. The thermal time-constant spectra extracted using this method can describe the subtle temperature variations in the AlGaN/GaN HEMT active region. This will help researchers to precisely analyze the layer composition of the heat-flow path.