Structure and Fabrication Method of High Voltage Junction Field Effect Transistor

Abstract

The invention discloses a high-voltage junction field effect transistor structure. An inversion layer is filled into a deep channel of a body region of the structure. The invention further discloses a manufacture method of the high-voltage junction field effect transistor structure (HV JFET) structure. The manufacture method comprises the steps of manufacturing the inversion layer in the deep channel of the body region through a photoetching and ion implantation process while manufacturing a substrate trap of a manufacture body region or the inversion layer of a drain terminal drifting region in the HV JFET conventional manufacture process. By filling one opposite type of impurities into the deep channel of the JFET body region, the impurity concentration of the channel of the JFET body region is reduced on a basis that any photoetching layer is not increased, the channel is easily used up, and accordingly the pinch-off voltage of an HV JFET device is effectively reduced.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to a structure of a high-voltage junction field effect transistor and a preparation method thereof. Background technique [0002] The traditional high-voltage junction field effect transistor (High-Voltage Junction Field Effect Transistor, HVJFET) generally consists of two parts, the Drain (drain) end drift region and the JFET body region, such as figure 1 shown. in, [0003] The drain drift region mainly plays the role of high voltage resistance, and has a DNW (N-type deep well). Since the N-type impurity concentration in DNW is too light, it will affect the on-resistance, so it needs to be made relatively thicker, and an additional layer of inversion implantation is added, such as figure 1 In the Ptop (P-type buried layer), to balance its charge. [0004] The body region is mainly used to control the magnitude of the JFET current and the pinch-off ...

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Problems solved by technology

[0005] The HV JFET device with this structure, because its body region channel is only composed of a single impurity (N-type or P-type), that is, the concentration of the impurity is relatively high, and the channel path is not easy to be depleted. Therefore, the pinch-off voltage of the device will be higher

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