Half self alignment bipolar transistor and manufacturing method thereof

Abstract

The invention discloses a half self alignment bipolar transistor. Boron doping oxidation films are formed on both the upper face and the lower face of an outer base region, doping of the outer base region can be achieved through boron diffusion in the oxidation films, and so that the high doping density of the outer base region can be ensured. An emitter region is only formed by polycrystalline silicon which is formed in a window of the emitter region, the coupling region of the emitter region and the outer base region can be decreased, the stray capacitance of the emitter region and base regions can be lowered, the width of the outer base region can further be enabled to be minimum within the range of process capability, the stray capacitance of the outer base region is lowered, and thus the frequency characteristic and the performance of a device can be enhanced. The invention further discloses a manufacturing method of the half self alignment bipolar transistor. Ion implantation technology is of no need for doping of the outer base region, and the costs of photoetching mask plates and ion implantation can be lowered. Due to the facts that the emitter region can be etched comprehensively in a returning mode, and the side wall of the emitter region does not need to be manufactured, the photoetching mask plates can be saved, and process cost and complexity are lowered.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuits, in particular to a semi-self-aligned bipolar transistor. The invention also relates to a method of manufacturing the semi-self-aligned bipolar transistor. Background technique [0002] In radio frequency applications, higher and higher device characteristic frequencies are required. Although RFCMOS can achieve higher frequencies in advanced process technologies, it is still difficult to fully meet radio frequency requirements. For example, it is difficult to achieve characteristic frequencies above 40GHz, and advanced technology The research and development cost of compound semiconductors is also very high; compound semiconductors can realize very high characteristic frequency devices, but due to the disadvantages of high material cost and small size, and the toxicity of most compound semiconductors, its application is limited. Silicon germanium (SiGe) heterojunction bipolar tran...

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Problems solved by technology

The technology of this device is mature and reliable, but the main disadvantages are: 1. The epitaxy cost of the collector area is high; 2. The formation of collector pick-up depends on high-dose and high-energy ion implantation to lead out the buried layer of the collector area. The device area is large; 3. The deep trench isolation process is complicated and the cost is high; 4. The number of photolithography layers in the HBT process is large

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