Based on the concept of critical field EI,C approaching for dielectric layer, the ENDIF (Enhanced Dielectric layer Field) principle for SOI HV devices is proposed for the first time, from which three approaches to enhance field of dielectric layer EI for increasing vertical breakdown voltage VB,V are presented: enhance ① the critical field in silicon ES,C at the interface of Si/dielectric layer by using thin silicon layer. Considering the threshold energy of silicon sT, the expression of ES,C for both thick and thin Si layer is derived firstly and shown that ES,C increases sharply with decreasing of thin Si layer thickness tS and ES,C and EI for SiO2 are up to 141Vμm and 422V/μm at tS=0.1μm, respectively; ②raise a structure of buried dielectrics layer with low permittivity (LK) and variable permittivity (VK) ③implement the interface charges between silicon and dielectric layer, from which a new dielectric structure with DT SOI is proposed, and I of 300V/μ m is experimentally obtained. By ENDIF, the formula EI and VB,V are given, which are meet good with 2D simulation and experimental results. With ENDIF, several conventional SOI devices are well explained.
展开▼
