How to make a bipolar transistor

Abstract

The invention relates to a bipolar transistor and a manufacturing method therefor. Before the forming of emitter electrode polysilicon, the manufacturing method comprises the following steps: forminginsulating protection layers on an oxidation layer and an N-type epitaxial layer at a first opening; forming photoresist on the insulating protection layer at the first opening, wherein the photoresist comprises a first part located at the center of the opening, and a plurality of second parts which are located at two sides of the first part at intervals; carrying out the wet corrosion of the insulating protection layers through the photoresist, enabling the insulating protection layers to form a first protection part located at the center of the first opening and a plurality of second protection parts which are located at two sides of the first protection part at intervals; forming base polysilicon on the oxidation layer, the second protection part and a part of the first protection partadjacent to the second protection parts and forming silicon oxide on the base polysilicon. The insulating protection layers serve as emitter region protection materials, thereby avoiding an emitter-base short circuit fault.

Description

【Technical field】 [0001] The invention relates to the technical field of semiconductor manufacturing technology, in particular, to a method for manufacturing a bipolar transistor. 【Background technique】 [0002] It originated from the point-contact transistor transistor invented in 1948, and developed into a junction transistor in the early 1950s, which is now called a bipolar transistor. There are two basic structures of bipolar transistors: PNP type and NPN type. In these three layers of semiconductors, the middle layer is called the base region, and the outer two layers are called the emitter region and the collector region. When a small amount of current is injected into the base region, a larger current will form between the emitter region and the collector region, which is the amplification effect of the transistor. In bipolar transistors, both electrons and holes conduct electricity. Compared with field effect transistors, bipolar transistors have slow switching sp...

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Problems solved by technology

If the amount of etching is increased, the silicon at the bottom (that is, the surface of the emitter region) will be damaged, which will cause the device amplification factor to be unstable.

If the amount of etching is reduced, it may lead to unclean etching of polysilicon, which will eventually lead to device emitter-base short circuit and device failure, thus affecting the reliability of the device

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