A novel low specific on-resistance （Ron,sp） lateral double-diffused metal oxide semiconductor （LDMOS） with a buried improved super-junction （BISJ） layer is proposed. A super-junction layer is buried in the drift...A novel low specific on-resistance （Ron,sp） lateral double-diffused metal oxide semiconductor （LDMOS） with a buried improved super-junction （BISJ） layer is proposed. A super-junction layer is buried in the drift region and the P pillar is split into two parts with different doping concentrations. Firstly, the buried super-junction layer causes the multiple-direction assisted depletion effect. The drift region doping concentration of the BISJ LDMOS is therefore much higher than that of the conventional LDMOS. Secondly, the buried super-junction layer provides a bulk low on-resistance path. Both of them reduce Ron,sp greatly. Thirdly, the electric field modulation effect of the new electric field peak introduced by the step doped P pillar improves the breakdown voltage （BV）. The BISJ LDMOS exhibits a BV of 300 V and Ron,sp of 8.08 mΩ·cm2 which increases BV by 35% and reduces Ron,sp by 60% compared with those of a conventional LDMOS with a drift length of 15 μm, respectively.展开更多
A RESURF-enhanced high voltage SOl LDMOS （ER-LDMOS） with an ultralow specific on-resistance （Ron, sp） is proposed. The device features an oxide trench in the drift region, a P-pillar at the sidewall of the trench,...A RESURF-enhanced high voltage SOl LDMOS （ER-LDMOS） with an ultralow specific on-resistance （Ron, sp） is proposed. The device features an oxide trench in the drift region, a P-pillar at the sidewall of the trench, and a buried P-layer （BPL） under the trench. First, the P-pillar adjacent to the P-body not only acts as a vertical junction termination extension （JTE）, but also forms a vertical reduced surface field （RESURF） structure with the N- drift region. Both of them optimize the bulk electric field distributions and increase the doping concentration of the drift region. Second, the BPL together with the N-drift region and the buried oxide layer （BOX） exhibits a triple- RESURF effect, which further improves the bulk field distributions and the doping concentration. Additionally, multiple-directional depletion is induced owing to the P-pillar, the BPL, and two MIS-like structures consisting of the N-drift region combined with the oxide trench and the BOX. As a result, a significantly enhanced-RESURF effect is achieved, leading to a high breakdown voltage （BV） and a low Ron, sp. Moreover, the oxide trench folds the drift region in the vertical direction, resulting in a reduced cell pitch and thus Ron, sp. Simulated results show that the ER-LDMOS improves BV by 67% and reduces Ron, sp by 91% compared with the conventional trench LDMOS at the same cell pitch.展开更多
基金Project supported by the National Science and Technology Project of the Ministry of Science and Technology of China(Grant No.2010ZX02201)the National Natural Science Foundation of China(Grant No.61176069)the National Defense Pre-Research of China(Grant No.51308020304)
文摘A novel low specific on-resistance （Ron,sp） lateral double-diffused metal oxide semiconductor （LDMOS） with a buried improved super-junction （BISJ） layer is proposed. A super-junction layer is buried in the drift region and the P pillar is split into two parts with different doping concentrations. Firstly, the buried super-junction layer causes the multiple-direction assisted depletion effect. The drift region doping concentration of the BISJ LDMOS is therefore much higher than that of the conventional LDMOS. Secondly, the buried super-junction layer provides a bulk low on-resistance path. Both of them reduce Ron,sp greatly. Thirdly, the electric field modulation effect of the new electric field peak introduced by the step doped P pillar improves the breakdown voltage （BV）. The BISJ LDMOS exhibits a BV of 300 V and Ron,sp of 8.08 mΩ·cm2 which increases BV by 35% and reduces Ron,sp by 60% compared with those of a conventional LDMOS with a drift length of 15 μm, respectively.
基金Project supported by the National Natural Science Foundation of China(Nos.61176069,61376079)
文摘A RESURF-enhanced high voltage SOl LDMOS （ER-LDMOS） with an ultralow specific on-resistance （Ron, sp） is proposed. The device features an oxide trench in the drift region, a P-pillar at the sidewall of the trench, and a buried P-layer （BPL） under the trench. First, the P-pillar adjacent to the P-body not only acts as a vertical junction termination extension （JTE）, but also forms a vertical reduced surface field （RESURF） structure with the N- drift region. Both of them optimize the bulk electric field distributions and increase the doping concentration of the drift region. Second, the BPL together with the N-drift region and the buried oxide layer （BOX） exhibits a triple- RESURF effect, which further improves the bulk field distributions and the doping concentration. Additionally, multiple-directional depletion is induced owing to the P-pillar, the BPL, and two MIS-like structures consisting of the N-drift region combined with the oxide trench and the BOX. As a result, a significantly enhanced-RESURF effect is achieved, leading to a high breakdown voltage （BV） and a low Ron, sp. Moreover, the oxide trench folds the drift region in the vertical direction, resulting in a reduced cell pitch and thus Ron, sp. Simulated results show that the ER-LDMOS improves BV by 67% and reduces Ron, sp by 91% compared with the conventional trench LDMOS at the same cell pitch.
