【摘要】：SiC作為第三代半導(dǎo)體中的佼佼者,具有優(yōu)越的電學(xué)性能,能夠工作在高溫,大功率,高頻等特殊環(huán)境下。而JBS作為高耐壓,高速,大電流的功率二極管,被認(rèn)為是發(fā)展最快,前景最好的一類二極管。本文針對(duì)平面JBS的不足,提出了一種改進(jìn)結(jié)構(gòu)-溝槽結(jié)構(gòu)的JBS(TJBS),并用Sentaurus-TCAD軟件進(jìn)行了仿真優(yōu)化,普通JBS由于受離子注入深度的限制,相鄰的pn結(jié)勢(shì)壘對(duì)中間的肖特基結(jié)的保護(hù)作用有限。引入溝槽后,pn結(jié)深度變得可以調(diào)整,TJBS可以獲得更大的pn結(jié)結(jié)深,在相同間距下,電場(chǎng)屏蔽效應(yīng)得以增強(qiáng)從而使器件的反向漏電流顯著降低。首先研究了TJBS單胞結(jié)構(gòu),使用1200V的器件參數(shù):外延層厚度10μm,摻雜濃度5×15/cm3,針對(duì)兩種單胞結(jié)構(gòu)-先注入后刻槽結(jié)構(gòu)(TJBS_A)和先刻槽后注入結(jié)構(gòu)(TJBS_B),通過(guò)對(duì)比發(fā)現(xiàn):由于后者能夠在相同注入能量條件下實(shí)現(xiàn)更大的注入深度,且工藝更簡(jiǎn)單,故其性能優(yōu)于前者;隨后針對(duì)TJBS_B,研究了槽深與注入深度相對(duì)性,槽寬與注入寬度相對(duì)性以及套刻偏差對(duì)其正反向特性的影響。只有在注入寬度大于槽寬的情況下才能發(fā)揮該結(jié)構(gòu)降低反向漏電流的優(yōu)勢(shì)。在此條件情況下,注入深度越大反向漏電流越低。在允許的套刻偏差內(nèi)(1μm以下),套刻偏差的存在對(duì)器件性能的影響較小。在相同注入深度和相同注入比的情況下溝槽JBS相比對(duì)平面JBS對(duì)肖特基區(qū)的保護(hù)作用更強(qiáng),能夠在相同擊穿電壓條件下獲得更好的正向性能。然后研究了帶有場(chǎng)限環(huán)終端的TJBS完整結(jié)構(gòu),加入了對(duì)終端刻槽的討論,發(fā)現(xiàn)主結(jié)和場(chǎng)限環(huán)同時(shí)刻槽時(shí)器件的性能最優(yōu)。
[Abstract]:As a leader in the third generation semiconductors, SiC has superior electrical properties and can work in high temperature, high power, high frequency and other special environments. As a high voltage, high speed and high current power diode, JBS is considered to be the fastest developing and the most promising diode. In order to overcome the shortcomings of plane JBS, an improved structure-groove structure JBS (TJBS), is proposed and optimized by Sentaurus-TCAD software. Due to the limitation of ion implantation depth, the potential barrier of adjacent pn junction has limited protective effect on the middle Schottky junction. With the introduction of grooves, the depth of pn junction can be adjusted, and the depth of pn junction can be obtained by TJBS. At the same spacing, the shielding effect of electric field can be enhanced, so that the reverse leakage current of the device can be significantly reduced. Firstly, the TJBS unit cell structure is studied. The device parameters of 1200 V are as follows: the thickness of epitaxial layer is 10 渭 m, the doping concentration is 5 脳 15 鈮，

本文編號(hào)：2506460