METHOD OF MAKING MICROWAVE LDMOS-TRANSISTOR CRYSTALS WITH MULTILAYER DRIFT DRAIN REGION Russian patent published in 2024 - IPC H01L21/335 H01L21/336 

FIELD: microelectronic equipment.

SUBSTANCE: method of making microwave LDMOS-transistor crystals on a silicon substrate in a high-resistance p-type epitaxial layer includes forming source, drain, gate regions, several diffusion drain regions with different depth and degree of doping, and multilayer metallization using operations of photolithography, etching and ion doping of corresponding layers and regions. According to the invention, a drift drain region is formed, characterized by non-uniform and non-monotonic distribution of impurities in both longitudinal and transverse directions and consisting of four layers forming three sections, differing in depth and total depth of impurity atoms, in each of these sections, the local maximum of the impurity distribution is located at a certain depth.

EFFECT: invention makes it possible to produce microwave LDMOS-transistor crystals, which combine high reliability and improved values of specific electrical parameters, including drain current and drain-source resistance in open state.

1 cl, 8 dwg, 1 tbl