本项目基于SOI横向SJ-LDMOS引入等效耐压层(EVL)概念，将电荷补偿层与介质埋层看作EVL，凭借对横向SJ模型与技术的创新性研究，使得横向SJ耐压能力与纵向SJ类似。创新点有3个：(1)建立EVL模型，剖析横向SJ耐压机理：在器件漂移区求解3D泊松方程，得到表面场级数解及N/P条中线电场简化式，并求解具有任意掺杂电荷补偿层EVL表面场分布进而得到优化掺杂,其实横向SJ耐压设计本质就是对EVL表面场分布的设计。 (2)揭示衬底辅助耗尽效应(SAD)物理本质及降低途经，SAD本质是 EVL不能提供表面SJ层理想均匀场边界，其电中性条件不能满足，破坏N/P条电荷平衡，器件耐压降低。所以降低SAD就是使EVL产生均匀表面电场。(3)提出SOI基线性浅结优化补偿层SJ-LDMOS新结构。新器件消除SAD效应，实现埋氧层介质场增强(ENDIF)效果，本项目将根据上述模型及技术对新器件流片验证。

The concept of the equivalent voltage sustainable layer (EVL) is introduced in the lateral SJ-LDMOS based on SOI. The EVL is defined as the combination of the charge compensation layer and the dielectric layer. The voltage capacity of the lateral SJ is similar to that of the vertical SJ by the innovative research on the model and technology of the lateral SJ. Three innovatives is as following: (1) The EVL model is established and the breakdown mechanism of the lateral SOI SJ device is revealed. The series solution of the surface field and the simplified electric field of N/P middle line are obtained by solving 3D Poisson's equation in the drift region,and the optimal doping is achieved by solving the surface field distribution of the EVL with arbitrary doping charge compensation layer. The essence of voltage design of the lateral SJ is the design of the EVL surface field. (2)The essence of SAD(Substrate Assisted Depletion) effect and the reducing method of the SAD are revealed. The essence of the SAD is that the EVL can't provide the ideal uniform field boundary of the surface SJ layer, so that the electric neutral condition can't be satisfied, then the N/P pillars'charge balance is destroyed and the breakdown voltage is decreased.The EVL produce a uniform surface electric field by reducing the SAD.(3)The new structure which the line thin junction compensation layer SJ-LDMOS based on SOI is proposed.The new structure can eliminate the SAD and realize ENDIF(Enhanced Dielectric layer Field) effect. The chip will be test to base on the above model and the technology in project.