Static and dynamic performance evaluation of > 13 kV SiC p-channel IGBTs at high temperatures

Retrograde p-Well for 10-kV Class SiC IGBTs

“…The 10kV class SiC IGBT research has gained significant momentum since the inception of the first 10kV p-IGBT on 4H-SiC in 2005 by Zhang et al, particularly, in the aftermath of realization of high-voltage n-channel devices on free-standing 4H-SiC epilayers in 2010 by Wang et al [4,5]. Extensive efforts have been put lately on realizing SiC IGBTs in the 10kV-30kV voltage range where they can offer a more favorable trade-off between the conduction and switching losses when compared with unipolar counterparts [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

“…Although, the processing of n-channel IGBTs is particularly challenging, both the breakdown voltage and specific on-resistance have significantly improved due to important breakthroughs in bulk/epilayer growth and controlled post-process substrate grinding [21]. N-epilayers can be grown as thick as 200µm with a good control on the doping concentration in the range 1×10 14 -3×10 14 cm -3 [15][16][17][18]. Defect density is acceptable in terms of realizing devices with an active area of 1cm×1cm and the carrier lifetime (τ) is approaching ~12µs [21].…”

“…Whilst great emphasis is being placed on the breakdown voltage, a reliable control of the gate threshold voltage (Vth) has emerged as a critical issue in the development of ultra-high voltage class (>10kV) of SiC IGBTs [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. A robust control over Vth is a prerequisite for a latch-up free and faster IGBT operation.…”

“…To have Vth in the range 5-7V, a 10kV SiC IGBT requires substantial reduction in the gate oxide thickness (tox), which in turn leads to long-term reliability issues. Previous studies have shown that the gate oxide thickness is restricted to 50-60nm [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The doping of conventional p-well can be lowered to further increase the oxide-thickness.…”

Simulation Study of 4H-SiC Trench Insulated Gate Bipolar Transistor with Low Turn-Off Loss

“…There are two mainstreams processing methods for a 4H-SiC insulated gate bipolar transistor (IGBT) at present: one is to make a good compromise between the forward and off characteristics of the device by properly setting the structural parameters of the device such as the n buffer's thickness and doping parameters [6], the minority carrier lifetime in the ndrift region [7,8], and thickness and doping parameters of the CSL (carrier storage layer) [9,10]; the other is by considering the process conditions and designing a special device structure that can improve by affecting certain characteristics, such as an anode short circuit IGBT [11,12], a super junction IGBT [13], or a collector trench IGBT (CT-IGBT) with an electronic extraction channel [14]. By analyzing the previous research, it can be observed that researchers have been mainly concerned with the compromise between the on-state and breakdown characteristics of IGBT devices, and that relatively little research has been made into the dynamic conversion characteristics of the device.…”