本文選題：LPCVD-SiNx　切入點(diǎn)：GaN　出處：《西安電子科技大學(xué)》2015年碩士論文

【摘要】：本文主要關(guān)注基于LPCVD-SiNx介質(zhì)的GaN基器件界面特性的研究,通過(guò)C-V電學(xué)測(cè)試,結(jié)合頻率崩塌法、電導(dǎo)法以及Terman法等對(duì)GaN基器件界面質(zhì)量進(jìn)行定量表征,再輔以I-V測(cè)試,以期對(duì)GaN基MIS結(jié)構(gòu)、GaN MISHEMT器件中SiNx/GaN界面質(zhì)量從物理機(jī)制方面有一個(gè)全面的認(rèn)識(shí)和理解。首先利用Silvaco公司的Atlas仿真器分別對(duì)GaN MIS及GaN MISHEMT進(jìn)行了C-V仿真以及不同柵壓偏置下能帶的仿真,為器件C-V相關(guān)電學(xué)行為的物理機(jī)理分析提供了科學(xué)的理論依據(jù)。本論文還系統(tǒng)比較了對(duì)GaN基器件界面特性進(jìn)行定量表征的多種方法。針對(duì)GaN MIS結(jié)構(gòu),采用了頻率崩塌法、電導(dǎo)法和Terman法這三種研究方法進(jìn)行定量表征界面特性參數(shù)—界面態(tài)密度Dit的提取,而針對(duì)GaN MISHEMT器件,由于其具有兩個(gè)界面不適合使用Terman法,故僅采用了頻率崩塌法和電導(dǎo)法。結(jié)果發(fā)現(xiàn),頻率崩塌法的Dit往往最高,電導(dǎo)法最低,中間是Terman法。各種研究方法或者說(shuō)界面態(tài)提取方法各有利弊,我們需要根據(jù)實(shí)際的實(shí)驗(yàn)條件和實(shí)驗(yàn)?zāi)康膩?lái)科學(xué)地選擇界面態(tài)密度提取方法。對(duì)先780℃LPCVD生長(zhǎng)SiNx介質(zhì)再分別進(jìn)行650℃、830℃歐姆合金退火的兩種SiNx/GaN MIS結(jié)構(gòu)進(jìn)行C-V測(cè)試和I-V測(cè)試。對(duì)于C-V測(cè)試的研究主要基于頻率崩塌法、電導(dǎo)法和Terman法對(duì)界面特性的定量表征。三種研究結(jié)果都表明,高溫退火樣品界面態(tài)密度要高于低溫退火。I-V測(cè)試則表明,高溫退火樣品的電流密度更小,擊穿電壓更高,并且從Poole-Frenkel陷阱深度提取結(jié)果發(fā)現(xiàn),可能與Si懸掛鍵和Si-H鍵有關(guān)。結(jié)合界面態(tài)密度結(jié)果,提出了界面處Si-H鍵在高溫合金退火過(guò)程中釋放出H原子,留下更多Si懸掛鍵,產(chǎn)生更多的界面態(tài),故而具有更高的界面態(tài)密度。對(duì)先780℃LPCVD生長(zhǎng)SiNx介質(zhì)再進(jìn)行830℃歐姆合金退火的典型的GaN MISHEMT器件的界面特性進(jìn)行研究。為定量表征出界面質(zhì)量,采用頻率崩塌法和電導(dǎo)法對(duì)界面態(tài)密度進(jìn)行提取。電導(dǎo)法依據(jù)柵壓偏置不同可以分別表征出SiNx/GaN界面和異質(zhì)結(jié)界面。研究結(jié)果表明,電導(dǎo)法提取的Dit要低于頻率崩塌法2~3個(gè)量級(jí),且半導(dǎo)體表面的Dit比異質(zhì)結(jié)界面處的Dit高了1個(gè)量級(jí)。最后對(duì)GaN MISHEMT進(jìn)行了基于三個(gè)典型的靜態(tài)偏置點(diǎn)(VGSQ,VDSQ)=(0,0)、(-15V,0)和(-15V,30V)的脈沖I-V測(cè)試,界面態(tài)陷阱也是影響脈沖I-V特性很重要的因素,這里通過(guò)對(duì)三個(gè)靜態(tài)偏置點(diǎn)下脈沖I-V輸出特性與直流I-V輸出特性的對(duì)比,進(jìn)行了基于自熱效應(yīng)和陷阱俘獲電子的科學(xué)解釋,進(jìn)一步驗(yàn)證了本文基于LPCVD-SiNx介質(zhì)的GaN MISHEMT器件高質(zhì)量的SiNx/GaN界面。綜上所述,本文對(duì)基于LPCVD-SiNx介質(zhì)的GaN基器件界面特性進(jìn)行了一系列的基礎(chǔ)研究與探索,并取得了一些初步的獨(dú)創(chuàng)性成果,也對(duì)實(shí)際的GaN器件的工藝制備和可靠性分析起到了啟發(fā)性和指導(dǎo)性的作用。
[Abstract]:This paper focuses on the research of GaN based device interface characteristics of LPCVD-SiNx media based on C-V by electrical measurement, combined with frequency collapse method, quantitative characterization of GaN based interface quality conductance method and Terman method, supplemented by the I-V test, in order to GaN based MIS structure, SiNx/GaN interface quality GaN MISHEMT devices from the physical mechanism have a comprehensive understanding and understanding. We use Silvaco's Atlas GaN and GaN MIS respectively on the simulator MISHEMT C-V simulation and simulation under different gate bias band, provides a theoretical basis for the scientific analysis of the physical mechanism for electric device C-V behavior. This paper also compared a variety of methods the quantitative characterization of the interfacial properties of GaN based devices. According to the GaN MIS structure, the frequency of collapse, the three research methods of conductivity and the Terman method for the quantitative characterization of interface 鐗規(guī)，

本文編號(hào)：1689325