The Rule of Field Enhancement for Buried Dielectric Layer of SOI High Voltage Devices

Based on the concept of critical field E
_I,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 E
_I
for increasing vertical breakdown voltage V
_B,v
are presented: (1) enhance the critical field in silicon E
_S,C
at the interface of Si/dielectric layer by using thin silicon layer. Considering the threshold energy of silicon E
_T
, the expression of E
_S,C
for both thick and thin Si layer is derived firstly and shown that E
_S,C
increases sharply with decreasing of thin Si layer thickness t
_s
and E
_S,C
and E
_I
for SiO
₂
are up to 141V /mum and 422 V /mum at t
_s
= 0.1mum, respectively; (2) raise a structure of buried dielectrics layer with low permittivity (LK) and variable permittivity (VK) (3) implement the interface charges between silicon and dielectric layer, from which a new dielectric structure with DT SOI is proposed, and E
_I
of 300 V/mum is experimentally obtained. By ENDIF, the formula E
_I
and V
_B,V
are given, which are meet good with 2D simulation and experimental results. With ENDIF, several conventional SOI devices are well explained.