Kirk effect and suppression for 20 V planar active-gap LDMOS
Kirk effect and suppressing for 20 V planar active-gap LDMOS Nie Weidong(聂卫东)1, 2, Yi Fayou(易法友)2, and Yu Zongguang(于宗光)1

For 20 V planar active-gap lateral double-diffused MOSFET (LDMOS), the sectional channel is utilized to decrease the electric field in the n-drift region below the poly gate edge in the off-state, compared with the conventional single channel. Then the n-drift concentration can be increased to decrease the Kirk effect, while keeping off-state breakdown voltage Vbd unchanged. Meanwhile the influence of the n-drift concentration and the n-drift length Ldrift (the drain n+ diffusion to gate spacing) which are related to the Kirk effect is discussed. The trade-offs between Rdson·Area, breakdown voltage Vbd and the electrical safe operating area (e-SOA) performance of LDMOS are considered also. Finally the proposed planar active-gap LDMOS devices with varied values of Ldrift are experimentally demonstrated. The experimental results show that the Kirk effect can be greatly suppressed with slight increase in the Rdson·Area parameter.