A novel substrate termination technology for lateral double-diffused MOSFET based on curved junction extension

Abstract

In this paper, a novel substrate termination technology (STT) for lateral double-diffused MOSFET (LDMOS) based on curved junction extension is proposed and experimentally demonstrated. A low-doped P-substrate, which is inserted in the curved region of the LDMOS, adjusts the high-doped abrupt P-body/N-drift junction with small curvature radius to low-doped P-sub/N-drift junction with large curvature radius, thus reducing peak electric field and avoiding premature avalanche breakdown at the curved abrupt P-body/N-drift junction. The proposed STT has been applied to a super junction (SJ) LDMOS. The experimental results show that the SJ LDMOS with the proposed STT exhibits off-state breakdown voltage (BV) of 800 V, which is the highest BV for the reported SJ LDMOS by far.

Optimization of Lateral Superjunction Based on the Minimum Specific ON-Resistance

“…To analyze this effect, the equivalent substrate (ES) model was proposed in [1] to give the optimized substrate conditions. The superior R ON performances have been reported by both the experiments [2]- [8], [11], [14] and the simulations [9], [10], [12], [13], in which R ON values were given for the special doping points [2]- [9], [11], [14] or with the dose of 2 × 10 12 cm −2 from the reduced surface field [10], [12], [13]. Yet less attention has been paid to the analytical R ON optimization of the SJ-LDMOS based on its 3-D field distribution.…”

“…The optimization results in this paper are compared with the other SJ-LDMOSs [2]- [14], including our previous works, as shown in Fig. 8.…”

“…2) With the similar L d only, indicating that the SAD effects have been suppressed effectively [2], [8], [10], [13]. 3) With both the longer L d and lower N, as given in [3], [11], [12], and [14]. The larger improvements of R ON may be observed in the last two cases because of two reasons: first, the optimized N (6) with the same W and H as those in the references, and the simulated design results in this paper are given as the filled round dots.…”

“…T HE super junction (SJ) is widely studied in the lateral double-diffused MOSFET (LDMOS) to reduce the specific ON-resistance R ON for a given breakdown voltage V B [1]- [14]. The optimization of the lateral SJ device mainly focuses on the design of V B , i.e., the suppression of the substrate-assisted depletion (SAD) effect, which can be alleviated by removing the silicon substrate [2], [8] or introducing the charge compensation [1], [3]- [7], [9]- [14].…”

“…The optimization of the lateral SJ device mainly focuses on the design of V B , i.e., the suppression of the substrate-assisted depletion (SAD) effect, which can be alleviated by removing the silicon substrate [2], [8] or introducing the charge compensation [1], [3]- [7], [9]- [14]. To analyze this effect, the equivalent substrate (ES) model was proposed in [1] to give the optimized substrate conditions.…”