High thermal stability superjunction strained si/sige heterojunction bipolar transistor

Abstract

The invention discloses a super-junction stress Si / SiGe heterojunction bipolar transistor with a high thermostability. A SiGe virtual substrate structure is adopted by the transistor; and a Si<1-y>Ge<y> secondary collector region, a relaxation Si<1-y>Ge<y> collector region, a stress Si<1-x>Ge<x> base region and a stress Si emitter region are respectively and epitaxially grown on the SiGe virtual substrate structure. According to the transistor, by introducing a super-junction p-type layer parallel to the stress Si<1-x>Ge<x> base region to the relaxation Si<1-y>Ge<y> collector region, the purposes of improving the electric field distribution in a collector junction space-charge region, reducing the peak electronic temperature, inhibiting the impact ionization and improving a device breakdown voltage are achieved; and meanwhile, with the introduction of the super-junction p-type layer, the doping concentration and the phonon scattering rate of the relaxation Si<1-y>Ge<y> collector region are effectively reduced, and the thermal conductivity of the relaxation Si<1-y>Ge<y> collector region is improved; the transistor has the characteristics of large current gain and high breakdown voltage; the internal temperature distribution is significantly reduced, the characteristic frequency and the temperature sensibility are improved, and the high-thermostability work can be realized in a relatively wide working temperature range.

Description

technical field [0001] The invention relates to a strained silicon heterojunction bipolar transistor, in particular to a high thermal stability superjunction strained Si used in radio frequency and microwave fields such as point-to-point wireless communication systems (>120GHz), satellite systems, optical fiber systems, and 4G / 5G mobile communication systems. / SiGe heterojunction bipolar transistors. Background technique [0002] Compared with conventional SiGe heterojunction bipolar transistors (heterojunction bipolar transistors, HBTs), strained Si / SiGe HBTs have large current gain, high current handling capability, and excellent high-frequency characteristics. Especially with the full development of strained technology in the fourth generation SiGe process, strained Si / SiGe HBT will be used in the fields of sensors, imagers, high-bandwidth analog-to-digital converters, automotive radars, and high-linearity amplifiers for terahertz applications. play an increasingly im...

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Problems solved by technology

When the device is working at a high current, the self-heating effect can easily cause the drift of the static operating point and aggravate the thermal instability, which seriously limits the high-power stable operation of the device.

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