Manufacturing method for transverse PNP transistor

Abstract

The present invention discloses a manufacturing method for transverse PNP transistor, comprising the following steps: Step 1, buried layer injection and diffusion are executed in a P type substrate; Step 2, oxide layer removal is executed to a buried layer and a thick oxide layer is led to grow; Step 3, glue spreading, exposure and etching are executed to the thick oxide layer; Step 4, an epitaxial layer is selectively led to grow; Step 5, base electrode deep phosphorus injection and collecting electrode boron diffusion are executed; Step 6, polysilicon is deposited and polysilicon boron injection is executed; Step 7, polysilicon etching is executed to an emitter. The present invention manufactures transverse PNP transistors by leading the epitaxial layer to grow, utilizes an epitaxial bottom to isolate the emitter, can effectively decrease the loss of current carrier at the emitter bottom of devices, increases the concentration of the emitter, and effectively improves the gain of transverse PNP pipes.

Description

technical field [0001] The invention relates to the field of semiconductor technology, in particular to a method for manufacturing a lateral PNP transistor. Background technique [0002] The fabrication method of lateral PNP transistors is widely used in bipolar, bipolar CMOS and BCD devices, but current loss at the bottom of the emitter of the existing lateral PNP transistors results in loss of amplification gain of the PNP transistors. [0003] Such as Figure 1 to Figure 8 As shown, the existing method for making a lateral PNP transistor includes the following steps: the first step, implanting and diffusing the buried layer on the P-type substrate; the second step, removing the buried oxide layer, and growing an epitaxial layer; the third step, Glue, expose, etch and implant the base; the fourth step is base diffusion; the fifth step is boron implantation at the collector; the sixth step is collector diffusion; the seventh step is emitter boron implantation; The eighth s...

AI Technical Summary

Problems solved by technology

[0004] The special structure brought by the lateral PNP transistor manufactured by the existing method has a long drift width, and the side wall emits and absorbs electrons. The above characteristics determine that the amplification gain of the existing lateral PNP transistor is difficult to be significantly improved.

[0005] Although in the existing production method, the distance between the emitter and the collector can be reduced to achieve the change of the amplification gain, but the change of the distance will cause the breakdown voltage to decrease and cause new problems.

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