A FIN-LDMOS with Bulk Electron Accumulation Effect

• Published in: Micromachines (Basel) Vol. 14; no. 6; p. 1225
• Main Authors: Chen, Weizhong, Duan, Zubing, Zhang, Hongsheng, Han, Zhengsheng, Wang, Zeheng
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.06.2023; MDPI
• Subjects: Accumulation; bulk electron accumulation (BEA); BV and Ron,sp; Drift; Electric fields; Electrons; extended drain (ED); extended superjunction trench gate; Semiconductors; Silica; Silicon; Simulation; extended drain (ED); extended superjunction trench gate; BV and Ron,sp; bulk electron accumulation (BEA)
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi14061225

A thin Silicon-On-Insulator (SOI) LDMOS with ultralow Specific On-Resistance ( ) is proposed, and the physical mechanism is investigated by Sentaurus. It features a FIN gate and an extended superjunction trench gate to obtain a Bulk Electron Accumulation (BEA) effect. The BEA consists of two p-regions and two integrated back-to-back diodes, then the gate potential is extended through the whole p-region. Additionally, the gate oxide is inserted between the extended superjunction trench gate and N-drift. In the on-state, the 3D electron channel is produced at the P-well by the FIN gate, and the high-density electron accumulation layer formed in the drift region surface provides an extremely low-resistance current path, which dramatically decreases the and eases the dependence of on the drift doping concentration ( ). In the off-state, the two p-regions and N-drift deplete from each other through the gate oxide like the conventional SJ. Meanwhile, the Extended Drain (ED) increases the interface charge and reduces the . The 3D simulation results show that the and are 314 V and 1.84 mΩ∙cm , respectively. Consequently, the is high, reaching up to 53.49 MW/cm , which breaks through the silicon limit of the RESURF.