本文選題：4H-SiC　切入點(diǎn)：MOS電容　出處：《大連理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：與硅相比,第三代半導(dǎo)體碳化硅擁有極好的性質(zhì),比如高熱導(dǎo)率,高電子遷移率等,同時(shí)也是唯一一種能夠通過(guò)熱氧化過(guò)程生長(zhǎng)氧化膜的化合物半導(dǎo)體。然而直接通過(guò)熱氧化過(guò)程制作的4H-SiC MOS器件有著界面缺陷過(guò)多,氧化膜可靠性欠佳的問(wèn)題。其原因在于熱氧化生成的氧化膜中存在著許多缺陷,這些缺陷導(dǎo)致氧化膜擊穿所需要的激活能減小,降低了氧化膜電應(yīng)力的承受能力。因此減少氧化膜中的缺陷,提高氧化膜可靠性就成為了SiC MOSFET研究領(lǐng)域的關(guān)鍵問(wèn)題。本文使用電子回旋共振(ECR)氮等離子體處理工藝對(duì)通過(guò)熱氧化過(guò)程形成的氧化膜進(jìn)行處理,制作成為4H-SiC MOS結(jié)構(gòu)。通過(guò)I-V測(cè)試發(fā)現(xiàn),通過(guò)ECR氮等離子體處理工藝,SiO2/4H-SiC的勢(shì)壘高度有效地提高至2.67 eV,接近理論值2.7 eV,擊穿場(chǎng)強(qiáng)達(dá)到了10.90 MV/cm。采用階躍電流經(jīng)時(shí)擊穿(SCTDDB)方法研究了ECR氮等離子體處理對(duì)4H-SiC MOS氧化膜經(jīng)時(shí)擊穿(TDDB)行為的影響。實(shí)驗(yàn)發(fā)現(xiàn),ECR氮等離子體能夠有效提高氧化膜的擊穿電荷量與壽命,與未經(jīng)過(guò)當(dāng)?shù)入x子體處理的樣品相比,經(jīng)過(guò)處理的樣品擊穿電荷量與壽命分別提高了10-100倍和3-4個(gè)數(shù)量級(jí)。同時(shí),本文還發(fā)現(xiàn)經(jīng)過(guò)ECR氮等離子體處理后,樣品的耐受電場(chǎng)強(qiáng)度的能力有所提高,而且樣品的均一性有了很大提高,很小場(chǎng)強(qiáng)下就會(huì)被擊穿的樣品被消除,樣品的擊穿場(chǎng)強(qiáng)分布在一個(gè)較窄的范圍內(nèi)。為了解釋ECR氮等離子體處理對(duì)于4H-SiC MOS樣品TDDB行為的影響,本文使用了X射線光電子能譜(XPS)測(cè)試手段對(duì)4H-SiC MOS樣品的物理性質(zhì)進(jìn)行分析,結(jié)果表明,ECR氮等離子體處理能夠有效消除由于不完全氧化而產(chǎn)生的缺陷,鈍化界面,因此提高了氧化膜擊穿所需要的激活能,從而提高了樣品擊穿電荷量與壽命。以上結(jié)果表明,ECR氮等離子體處理能夠有效降低4H-SiC MOS柵氧化膜中的缺陷,提高樣品的擊穿電荷量與壽命,提高樣品的均一性以及對(duì)電場(chǎng)應(yīng)力的耐受能力,改善了4H-SiC MOS柵氧化膜的可靠性。
[Abstract]:Compared with silicon, the third generation of semiconductor silicon carbide has excellent properties, such as high thermal conductivity, high electron mobility, and only through a thermal oxidation process of oxide film growth of compound semiconductor. However directly through the 4H-SiC MOS device made of a thermal oxidation process of interface defects are excessive, the problem of poor reliability of oxide film the reason is that. There are a lot of defects formed by thermal oxidation in the oxide film, these defects lead oxide film breakdown required activation energy decreased, reducing the oxidation film ability to withstand stress. Thus reducing defects in oxide film, improve the reliability of the film becomes the key problem of SiC MOSFET research field. This paper use electron cyclotron resonance (ECR) plasma treatment process of nitrogen formed by thermal oxidation process of the oxide film, made 4H-SiC MOS structure by I-V test. Found by ECR plasma treatment, the barrier height of SiO2/4H-SiC effectively increased to 2.67 eV, close to the theoretical value of 2.7 eV, the breakdown strength reached 10.90 MV/cm. with step current time breakdown (SCTDDB) method to study the ECR of nitrogen plasma treatment on 4H-SiC MOS oxide TDDB (TDDB) the effect of experiments. Found that ECR plasma can effectively improve the breakdown of charge and life on film, and has not been compared when the plasma treated sample, after the sample breakdown of charge and life treatment were increased 10-100 times and 3-4 orders of magnitude. At the same time, this paper also found that after ECR nitrogen plasma treatment, tolerance, electric field strength of samples the increased and uniformity of the samples has been greatly improved, a small electric field will be the breakdown of samples is eliminated and the breakdown strength of samples distributed in a narrow Range. In order to explain the effect of ECR treatment for 4H-SiC MOS nitrogen plasma samples of TDDB behavior, this paper uses X ray photoelectron spectroscopy (XPS) of 4H-SiC MOS sample physical property testing methods were analyzed, the results show that the ECR plasma treatment can effectively eliminate the defects caused by the incomplete oxidation passivation interface, so the activation energy of the oxide film breakdown to improve, thereby improving the sample breakdown of charge and life. These results indicate that ECR nitrogen plasma treatment can effectively reduce the defects of 4H-SiC MOS gate oxide film, improve the breakdown of charge and life samples, improve the uniformity of the samples and the ability to tolerate stress field, improve the reliability of 4H-SiC MOS gate oxide.

【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TN386

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相關(guān)期刊論文 前1條

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本文編號(hào)：1578261