On the scaling limit of the Si-IGBTs with very narrow mesa structure

A Novel Approach to Suppress the Collector-Induced Barrier Lowering Effect in Narrow Mesa IGBTs

“…It can be observed from Fig. 2 that the conventional IGBT-A shows non-saturated tendency of the Jc-Vce characteristics due to CIBL effect [7]. The CIBL mechanism can be explained as follows: during forward conduction, the whole mesa region becomes conductivity modulated, which is caused by the hole current flowing into the inversion layers and n + -cathode, as shown in Fig.…”

“…Most recent developments on trench gated IGBTs are focussed upon scaling down mesa regions sandwiched between the gates to reduce on-state losses by enhancing the injection enhancement (IE) effect [3][4][5][6]. However, the IGBTs with very narrow mesa suffer from poor short circuit robustness because of the collector induced barrier lowering (CIBL) effect [7,8], which occurs at the P-base/n + -cathode junction caused by the conductivity modulation in the channel inversion layers [9].…”

Numerical Analysis of 3-D Scaling Rules on a 1.2-kV Trench Clustered IGBT

“…The self-clamping feature in the TCIGBT technology ensures that current saturation levels do not increase significantly as k increases. In contrast, the scaling work on IGBT technology suffers from the absence of current saturation, which is originated by the potential barrier lowering in the middle of mesa regions [8]. Fig.…”

“…The same effect is used in 1D scaling of mesa width [6], 2D and 3D scaling of cathode cells [3,4] as well as deep sub-micron designs [7]. However, the IE effect also results in non-saturation of the MOS channel current, leading to significant degradation of short circuit withstand capability [8,9]. During the short-circuit mode, devices need to sustain simultaneously high voltage and high current, causing a significant increase in the local device temperature due to high-power dissipation.…”

“…The device must survive under such abnormal conditions until the system protection circuit shuts down the driving signal. The reduction in short circuit capability in scaled TIGBT is attributed to the Collector Induced Barrier Lowering (CIBL) effect [8], which is caused by conductivity modulation in the MOS channels [9]. Unlike the IE effect in TIGBTs, The Trench Clustered IGBT (TCIGBT) utilizes controlled thyristor action (pnpn effect) to reduce on-state losses [10].…”