Manufacturing method and structure of bipolar transistor

Abstract

The invention discloses a manufacturing method of a bipolar triode. The manufacturing method includes the steps that an N-type lightly-doped epitaxial layer grows on a substrate; P-type ions are injected, and an intrinsic base region is formed; an emitter window dielectric layer is deposited and photoetched, and an emitter window is formed; the emitter window serves as a mask for injecting N-type ions in an emitter region; a furnace tube is annealed and pushed; emitter polycrystalline silicon is deposited and N-type heavy doping is conducted on the emitter polycrystalline silicon; the emitter polycrystalline silicon is photoetched; ion injection forming of an outer base region is conducted before photoresist is removed; the emitter polycrystalline silicon and doped impurities of the outer base region are activated through the rapid thermal annealing process. The invention further discloses the bipolar triode. The breakdown voltage of an emitter and a base can be increased, tunneling electric leakage between the emitter and the base is reduced, the breakdown voltage from the emitter to a collector of the whole device is increased, the process cost is low, and the cut-off frequency and the power gain of the device can be kept at high values.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor integrated circuits, in particular to a method for manufacturing a bipolar triode; the invention also relates to a bipolar triode. Background technique [0002] Bipolar transistors for conventional radio frequency applications require a cut-off frequency as high as possible under a certain breakdown voltage (BVCEO) of the collector and emitter regions. The main factors affecting the cut-off frequency are the base region and the base-collector region junction. The transit time of the formed depletion region. The cutoff frequency is inversely proportional to the transit time, which is proportional to the width of the base and junction depletion regions. The junction depletion region width is in turn proportional to the emitter-to-collector breakdown voltage. Therefore, in order to obtain a higher cut-off frequency under the same breakdown voltage, the narrower the base width is, the bett...

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Problems solved by technology

[0014] In the existing method, since both the outer base region and the emitter polysilicon are heavily doped, after the annealing of the furnace tube in step 8, the outer base region and the emitter polysilicon are heavily doped impurities that will advance to the emitter region and the base. In the PN junction region formed by the region, both the emitter region and the base region are heavily doped and formed as an abrupt junction, which reduces the breakdown voltage of the emitter-base junction and easily causes a gap between the emitter and the base. Increased tunneling leakage reduces the emitter-to-collector breakdown voltage across the device

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