具有高K背柵的無電壓回跳RC?IGBT靜態(tài)特性研究

摘" 要： 針對傳統(tǒng)RC?IGBT導通壓降大、擊穿電壓低等問題，提出一種具有高介電常數(shù)（高K）背柵的RC?IGBT器件結構，其特點是位于底部集電極的背柵介質采用高介電常數(shù)材料。高K介質增大了正向導通時背柵周圍的空穴濃度，不僅消除了電壓回跳，還降低了導通壓降。仿真結果表明：在高正向導通電流密度下（ICE=925 A/cm2），高K背柵RC?IGBT的導通壓降為1.71 V，相比傳統(tǒng)RC?IGBT降低了19.34%，相比氧化層背柵RC?IGBT降低了13.20%；另一方面，在阻斷狀態(tài)下，高K介質增強了背柵周圍的電子積累，增大了擊穿電壓。高K背柵RC?IGBT的擊穿電壓為1 312 V，相較于氧化層背柵RC?IGBT提高了44.18%。此外，高K背柵RC?IGBT的反向導通壓降相比傳統(tǒng)RC?IGBT降低了43.43%，相比氧化層背柵RC?IGBT降低了13.85%。將所提出的高K背柵的RC?IGBT應用于高壓、大功率的電子電力系統(tǒng)，可提高系統(tǒng)的可靠性并降低損耗。

關鍵詞： RC?IGBT； 電壓回跳； 高介電常數(shù)； 背柵； 導通壓降； 阻斷特性

中圖分類號： TN322.8?34" " " " " " " " " " " " " "文獻標識碼： A" " " " " " " " " " " 文章編號： 1004?373X（2025）04?0034?06

Research on static characteristics of snapback?free RC?IGBT with high K back gate

WANG Nan， XU Yonggen， HU Xiarong

（School of Science， Xihua University， Chengdu 610039， China）

Abstract： In allusion to the problem of high on?state voltage drop （Von） and the low breakdown voltage， a high permittivity （high K） back gate reverse conducting insulated gate bipolar transistor （HK?BG?RC?IGBT） device structure is proposed. Its characteristic is that the back gate dielectric located at the bottom collector is filled with HK. The HK dielectric increases the hole concentration around the back gate during the forward conduction， which not only eliminates the snapback?free， but also reduces Von. The simulation results show that， at high forward conduction current density （ICE=925 A/cm2）， the Von of HK?BG?RC?IGBT is 1.71 V， which is 19.34% lower than that of the conventional RC?IGBT （C?RC?IGBT） and 13.20% lower than that of OXIde back gate RC?IGBT （OXI?BG?RC?IGBT）. The HK dielectric enhances the electron accumulation around the BG in the blocking state， resulting in an increased breakdown voltage. The simulation results show that the breakdown voltage of the HK?BG?RC?IGBT is 1 312 V， which is increased by 44.18% compared with OXI?BG?RC?IGBT. In addition， the reverse Von of the HK?BG?RC?IGBT is reduced respectively by 13.85% and 43.43% compared with OXI?BG?RC?IGBT and C?RC?IGBT. Applying the proposed HK?BG?RC?IGBT to high?voltage and high?power electronic power systems can enhance the system reliability and reduce the loss.

Keywords：" RC?IGBT; snapback?free; high permittivity （high K）; back gate; on?state voltage drop; blocking state

0" 引" 言

絕緣柵雙極型晶體管（IGBT）因兼有場效應晶體管易驅動和雙極型三極管導通壓降低、電流密度大的優(yōu)點， 被廣泛應用于高壓功率器件[1?3]。從誕生以來，IGBT經歷了穿通型、非穿通型和場截止型的發(fā)展歷程，這三種結構都是針對導通特性和關斷特性提出的。但由于IGBT是由MOSFET和BJT組合而成，在器件內部未并聯(lián)續(xù)流二極管，因此沒有反向導通能力[4?5]。

為了使IGBT具有反向導通能力，節(jié)省芯片面積并降低成本和功耗，器件研究者將IGBT與續(xù)流二極管反向并聯(lián)集成在一起，稱為逆導型IGBT（Reverse Conducting IGBT， RC?IGBT）[6?8]。RC?IGBT將IGBT集電極部分區(qū)域替換為N+短路區(qū)，雖然實現(xiàn)了逆向導通，降低了寄生電阻，但在正向導通時，器件由單極型導通切換到雙極型導通模式，造成了電壓回跳[9?11]，不僅增大了器件的導通損耗，也不利于串并聯(lián)應用。……