Method for manufacturing laterally insulated-gate bipolar transistor

A method of manufacturing a lateral insulated-gate bipolar transistor, comprising the steps of:

• providing a wafer having a N-type buried layer, a shallow trench isolation (STI) structure formed on the N-type buried layer, a first N well formed on the N-type buried layer, and a first P well formed on the N-type buried layer;
• forming a high temperature oxide (HTO) film on the first N well by depositing, wherein a depositing temperature is between 750° C. to 850° C.;
• performing a thermal drive-in to the wafer, and performing first photolithography and etching to the HTO film to form a mini-oxide layer;
• performing second photolithography and first implantation of ion, thus forming a second N well in the first N well, and forming a second P well in the first N well and the first P well;
• forming a gate oxide layer and a polycrystalline gate subsequently, wherein one end of the gate oxide layer and the polycrystalline silicon gate extends to the second P well in the first N well, and the other end of the gate oxide layer and the polycrystalline silicon gate extends to the mini-oxide layer on the second N well;
• and
• performing third photolithography and second implantation of implanting N-type ions to a portion between the mini-oxide and the shallow trench insulation structure adjacent to the mini-oxide to form a drain, and forming a source in the second P well at the same time.