Field effect transistor gas sensor and array preparation method thereof

Abstract

The invention discloses a field effect transistor gas sensor and an array preparation method thereof. The field effect transistor (FET) gas sensor is a gate-sensitive FET gas sensor with a gate electrode modified by quantum dots, and a gate-sensitive electrode layer (5) of the FET gas sensor is of a two-layer composite structure or of a single-layer structure made of a composite material. The two-layer composite structure comprises a metal film layer and a quantum dot layer deposited on the surface of the metal film layer. The single-layer structure made of a composite material is specificallya single-layer structure made of a composite material formed by combining quantum dots and a metal or metalloid material. According to the invention, improvement is made on the internal composition and structure of the gate-sensitive FET, the corresponding preparation method and the like, quantum dots are used as a gate electrode and a gas sensitive layer at the same time, and the bias voltage ofthe gate electrode and the channel modulation effect are regulated and controlled by utilizing the adsorption characteristic of a quantum dot gate-sensitive electrode to different gases. A room-temperature gas sensor with high sensitivity, low power consumption and high selectivity can be obtained, and low-concentration target gases (such as H2) can be detected.

Description

technical field [0001] The invention belongs to the technical field of semiconductor gas sensors, and more specifically relates to a field effect transistor gas sensor and a preparation method thereof. The gas sensor uses quantum dots as a field effect transistor (FET) ) gas sensor is a gate sensitive FET gas sensor. Background technique [0002] Gas sensors are one of the most effective ways to obtain gas information in real time and in situ, and play an irreplaceable and important role in environmental protection, security alarm and other fields. At present, gas sensors are limited by sensitivity, integration and power consumption, and it is difficult to improve the applicability and reliability of multi-component complex atmosphere environments. Gas sensors based on field effect transistors (FETs) can operate under low current and low voltage conditions, which is conducive to the integration of silicon-based arrays, and has become one of the research hotspots in the fiel...

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Problems solved by technology

Patent CN2051351U discloses a "highly stable semiconductor hydrogen sensor", which is mainly composed of a hydrogen-sensitive Pd gate MOS device and heating resistors and other components for silicon-based integration to achieve highly stable and reliable hydrogen detection performance. However, the sensor requires heating assistance , which undoubtedly increases the power consumption of the device and limits the development of low-power IoT applications

Ali Javey et al. at the University of California, Berkeley used different metal materials (Pd, Ni, Au) as gates to construct FET array structures (Sci.Adv.2017,3(3),e1602557), which can selectively identify different gases , realizing the integration of multi-gas sensing units on a chip; however, the sensor baseline recovery requires thermal assistance, the detection power consumption is still high, and the response / recovery time is as long as 17 / 30 seconds, H 2 The minimum detection concentration is 3000ppm, which cannot satisfy the multi-component atmosphere environment for ultra-low concentration target gases (such as H 2 ) rapid monitoring

It can be seen that most of the current gate-sensitive FET gas sensors use a single metal Pd as the gate, and are generally only used for hydrogen detection. However, Pd metal is easily disturbed by the air environment (such as CO), and it is easy to generate phase As a result, the sensitivity, stability and power consumption of current hydrogen sensors are difficult to improve synergistically

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