Base region ring-doped anti-radiation lateral PNP transistor and preparation method thereof

Abstract

The invention discloses a base region ring-doped anti-radiation lateral PNP transistor and a preparation method thereof. According to the invention, after a lateral PNP transistor structure is formedconventionally, N-type impurity injection is carried out on the surface of an N-type base region of the lateral PNP transistor once through a photoresist masking injection method, an annular N+ dopedregion is formed on the surface of the N-type base region, and the position where the width Wb of the base region of the lateral PNP transistor is located is pushed into an N-type epitaxial layer bodyfrom the surface of the N-type epitaxial layer. When the lateral PNP transistor with the base region being of a ring structure is in a total dose irradiation environment, although accumulation of positive charges in an oxide layer causes depletion and inversion of a P-type collector region and depletion and inversion of the surface of a P-type emitter region, the width of the base region of the lateral PNP transistor is not affected due to the fact that the width Wb of the base region is moved downwards to the position below the depletion and inversion of the P-type collector region and the depletion and inversion of the surface of the P-type emitter region, so that the lateral PNP transistor with the base region being of the ring structure has high total dose radiation resistance.

Description

technical field [0001] The invention belongs to the technical field of PNP transistors, and in particular relates to a base ring doped radiation-resistant lateral PNP transistor and a preparation method thereof. Background technique [0002] The lateral PNP transistor is a transistor structure often used in bipolar integrated circuits. In the production of traditional bipolar integrated circuits, the diffusion process or ion implantation process is used to do the P-type impurity doping of the collector and emitter regions of the lateral PNP transistor, namely Selective P-type impurity doping is carried out on the N-type epitaxial layer to form the P-type collector region and P-type emitter region of the lateral PNP transistor. The epitaxial layer is used as the N-type base region of the lateral PNP transistor, and the lateral PNP is finally realized through the leads. In the transistor structure, a layer of silicon dioxide is covered on the surface of the transistor as an in...

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Problems solved by technology

[0003] The lateral PNP transistor has poor ability to resist total dose radiation: the total dose radiation will cause positive charges to be induced and accumulated in the silicon dioxide layer covering the surface of the transistor, which will induce negative charges on the surface of the transistor, resulting in the P-type collector / emitter of the lateral PNP transistor The surface of the region is depleted / inverted, and the holes injected into the base region are pushed to the substrate, the hole diffusion distance increases, and the width of the PNP transistor base region W B increase, the transport coefficient α T drop, beta drop

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