Method for adjusting characteristics of variable capacitance diode by using local secondary doping process

Abstract

The invention discloses a method for adjusting the characteristics of a variable capacitance diode by using a local secondary doping process, which comprises the following steps: using a B-C junction of an HBT material to make the variable capacitance diode and allowing an ohmic metal to form ohmic contact without passing through any high-temperature metallization process or quick metallization process according to the high doping characteristic of a base layer material in an HBT; and adopting a high-temperature-resistance mask film which is thickened for a plurality of times to protect regions not requiring secondary doping, using ion injecting equipment to secondarily dope a variable capacitance diode material region with doping elements, adjusting the doping components of the variable capacitance diode material region till the doping components enter a state suitable for manufacturing the hyperabrupt junction of the variable capacitance diode and protecting the regions not requiring secondary doping from the influences of the secondary doping. The method performs the secondary doping of a diode element material region requiring performance optimization and protects the characteristics of other regions of a circuit, thereby manufacturing a high quality variable capacitance diode while meeting the needs of other elements in the same sheet of semiconductor material.

Description

technical field [0001] The invention relates to the technical field of manufacturing semiconductor devices and integrated circuits, in particular to a method for adjusting the characteristics of a varactor diode by using a local secondary doping process. Background technique [0002] In modern semiconductor circuit technology, heterojunction bipolar transistor (HBT) technology is usually used in microwave integrated circuits due to its high frequency characteristics. For microwave integrated circuits with tuning functions, such as monolithic voltage-controlled oscillators, The varactor diode is its core tuning device. Varactor diodes with good linearity and sensitive control require hyperabrupt junction characteristics. For conventional integrated circuits with tuning functions, as shown figure 1 , it is necessary to fabricate transistors 101, varactor diodes 102, transmission lines and interconnection lines 103, passive devices 104 and other devices on the same substrate ...

AI Technical Summary

Problems solved by technology

At present, the common practice is to select one of the better junctions within the limitations of existing materials to make varactor diodes, and the obtained device characteristics cannot be optimized.

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