阅读说明：本技术 一种GaN基热敏器件及其制备方法 (GaN-based thermosensitive device and preparation method thereof ) 是由 仇志军 叶怀宇 张国旗 于 2019-09-12 设计创作，主要内容包括：本发明公开了一种GaN基热敏器件及其制备方法,包括：1)衬底上依次沉积GaN缓冲层和GaN高阻层；2)GaN高阻层上沉积n型掺杂GaN层；3)n型掺杂GaN层沉积SiO<Sub>2</Sub>介质层；4)刻蚀n型GaN层端部形成源极和漏极孔并沉积源电极和漏电极；5)SiO<Sub>2</Sub>介质层上沉积热释电材料；6)刻蚀热释电材料,沉积形成栅电极。本发明的GaN器件具有高电子迁移率、高导热率、高结温、高耐压等特点,具有很强的温度稳定性,适宜于电力环境应用；其次,热释电敏感材料本身无辐射,故无需制冷系统,可以工作在室温及其以上温度,器件功耗低；此外,该器件还具有探测光谱宽、工作频率广、灵敏度高且与波长无关、探测角度大等优点。(The invention discloses a GaN-based thermosensitive device and a preparation method thereof, wherein the preparation method comprises the following steps: 1) depositing a GaN buffer layer and a GaN high-resistance layer on the substrate in sequence; 2) depositing an n-type doped GaN layer on the GaN high-resistance layer; 3) deposition of SiO on n-type doped GaN layer 2 A dielectric layer; 4) etching the end part of the n-type GaN layer to form a source electrode hole and a drain electrode hole and depositing a source electrode and a drain electrode; 5) SiO 2 2 Depositing a pyroelectric material on the dielectric layer; 6) and etching the pyroelectric material, and depositing to form a gate electrode. The GaN device has the characteristics of high electron mobility, high thermal conductivity, high junction temperature, high voltage resistance and the like, has strong temperature stability, and is suitable for being applied in a power environment; secondly, the pyroelectric sensitive material is free of radiation, so that a refrigeration system is not needed, the pyroelectric sensitive material can work at room temperature or above, and the power consumption of the device is low; in addition, the device also has wide detection spectrum, wide working frequency and sensitivityHigh and independent of wavelength, large detection angle, etc.)

1. A GaN-based thermosensitive device and a preparation method thereof are characterized in that: comprises that

1) Depositing a GaN buffer layer and a GaN high-resistance layer on the substrate in sequence;

2) depositing an n-type doped GaN layer on the GaN high-resistance layer;

3) deposition of SiO on n-type GaN layer₂A dielectric layer;

4) etching the end part of the n-type GaN layer to form a source electrode hole and a drain electrode hole and depositing a source electrode and a drain electrode;

5)SiO₂depositing a pyroelectric material on the dielectric layer;

6) and etching the pyroelectric material, and depositing to form a grid.

2. The GaN-based thermosensitive device and the fabricating method thereof according to claim 1, wherein: the thickness of the GaN buffer layer in the step 1) is 0.2-4 mu m; the GaN high-resistance layer is semi-insulating GaN with the thickness of 0.5-2 μm.

3. The GaN-based thermosensitive device and the fabricating method thereof according to claim 1, wherein: the thickness of the n-type doped GaN layer in the step 2) is 10nm to 30nm, and the doping concentration is 1 multiplied by 10¹⁹cm^-3～5×10¹⁸cm^-3(ii) a The doping element is silicon.

4. The GaN-based thermosensitive device and the fabricating method thereof according to claim 1, wherein: in said 3) ofSiO₂The thickness of the dielectric layer is 10 nm-150 nm.

5. The GaN-based thermosensitive device and the fabricating method thereof according to claim 1, wherein: the pyroelectric material in the step 5) is TGS single crystal or LiTaO₃Single crystal, LiNbO₃Single crystal, Sr_1-xBa_xNb₆O₁₅Single crystal, PbZr_1-xTi_xO₃Ceramics, PbLiO₃Ceramic, polyvinylidene fluoride resin; the thickness of the pyroelectric material is 0.1-50 μm.

6. The GaN-based thermosensitive device and the fabricating method thereof according to claim 1, wherein: the thickness of the pyroelectric material in the step 5) is 5-60 μm.

7. A GaN-based thermosensitive device prepared according to the method of claims 1-6.

Technical Field

The invention relates to the field of thermosensitive devices, in particular to a GaN-based thermosensitive device and a preparation method thereof.

Background

The structure of a traditional pyroelectric temperature sensor is shown in fig. 1, and the basic working principle is that after a pyroelectric material absorbs external infrared radiation, the temperature changes to generate pyroelectric current, and then the current is amplified by an amplifying circuit at the rear end to form signal voltage output, so that information such as the temperature, the radiation intensity and the like of an external radiation source can be obtained. Since most of the amplification circuits integrated at the back end of the sensor are Si-based MOS transistors, the sensor is easily affected by the working environment, such as the temperature, electromagnetic radiation and pressure environment, so that the sensor has additional structures, such as a refrigeration system and an electromagnetic shield, and as a result, the system structure is complicated, and the volume and power consumption are increased. However, with the development of the demand, the requirements on the integration level, power consumption and working environment of the sensor are higher and higher, so that some temperature sensors with high integration level, high sensitivity, high pressure resistance, high temperature resistance and good electromagnetic radiation resistance are required.

Disclosure of Invention

Based on the problems and development requirements of the traditional pyroelectric temperature sensor, the invention innovatively provides a preparation method of a GaN-based thermosensitive device, which can meet the requirement of high-sensitivity temperature sensing, reduce the power consumption of the sensing device and improve the integration level, and in addition, the temperature sensor can work in the power complex environment of high temperature, high voltage, high-grade electromagnetic radiation and the like.

The specific method comprises

1) Depositing a GaN buffer layer and a GaN high-resistance layer on the substrate in sequence;

2) depositing an n-type doped GaN layer on the GaN high-resistance layer;

3) deposition of SiO on n-type doped GaN layer₂A dielectric layer;

4) etching the end part of the n-type GaN layer to form a source electrode hole and a drain electrode hole and depositing a source electrode and a drain electrode;

5)SiO₂depositing a pyroelectric material on the dielectric layer;

6) and etching the pyroelectric material, and depositing to form a grid.

Preferably, the thickness of the GaN buffer layer in the step 1) is 0.2-4 μm; the GaN high-resistance layer is semi-insulating GaN with the thickness of 0.5-2 mu m;

preferably, the thickness of the n-type doped GaN layer in the step 2) is 10nm to E30nm, doping concentration of 1 × 10¹⁹cm^-3～5×10¹⁸And the doping element is silicon.

Preferably, SiO in said 3)₂The thickness of the dielectric layer is 10 nm-150 nm.

Preferably, the pyroelectric material in 5) is TGS single crystal, LiTaO₃Single crystal, LiNbO₃Single crystal, Sr_{1- x}Ba_xNb₆O₁₅Single crystal, PbZr_1-xTi_xO₃Ceramics, PbLiO₃Ceramic, polyvinylidene fluoride resin; the thickness of the pyroelectric material is 0.1-50 μm;

the thickness of the pyroelectric material in the step 5) is 5-60 μm.

Preferably, a GaN-based thermosensitive device manufactured by the above method.

The pyroelectric material has a functional material with a good pyroelectric effect, namely, charge polarization change can occur due to temperature change. When the material absorbs external infrared radiation, the polarization intensity changes due to the change of the temperature of the material. The pyroelectric material is used as a gate contact material of a GaN MOS device, and when the pyroelectric material absorbs infrared radiation to generate a gate voltage signal output, the change of current in an n-type GaN layer (serving as a channel of the MOS device), namely the change of source and drain current, is caused. Therefore, the voltage or current signal output by the pyroelectric material due to radiation absorption can be obtained through the relation between the source-drain current and the gate voltage of the intrinsic GaN MOS device, and then the absorbed radiation quantity, the radiation source temperature and the like can be calculated by utilizing the intrinsic polarization characteristics of the pyroelectric material, so that temperature sensing is performed.

The invention has the advantages that:

(1) the thermosensitive device provided by the invention is a GaN-based MOS device, overcomes the defect that the traditional Si-based MOS device is greatly influenced by ambient temperature and pressure, has the advantages of temperature resistance, pressure resistance, radiation resistance and the like, and realizes the work in complex power environments of high temperature, high pressure and the like.

(2) The invention uses the functional material with good pyroelectric effect as the temperature sensitive material, so that the device has the advantages of non-refrigeration, wavelength-independent high-sensitivity temperature detection, wide spectral response, large detection angle, small power consumption and the like.

(3) The GaN material is used, and the GaN-based MOS device has high mobility, high switching speed and the like, so that the novel sensor has high response speed.

(4) The invention utilizes the inherent signal amplification characteristic of the MOSFET device to further improve the temperature detection sensitivity of the novel sensor.

(5) The thermosensitive device prepared by the invention has high integration level and is beneficial to the miniaturization of a temperature sensing system.

Drawings

In order to make the purpose, technical scheme and beneficial effect of the invention more clear, the invention provides the following drawings for illustration:

fig. 1 is a schematic view of a conventional pyroelectric temperature sensor.

Fig. 2 is a schematic two-dimensional cross-sectional structure of embodiment 1 of the present invention.

FIG. 3 is a flow chart of a manufacturing process of example 1 of the present invention.

FIG. 4 is a flow chart of a manufacturing process of example 2 of the present invention.

FIG. 5 is a flow chart of a manufacturing process of example 3 of the present invention.

Sapphire substrate 1, GaN buffer layer 2, high-resistance GaN layer 3, n-type doped GaN layer 4, SiO₂A dielectric layer 5, a pyroelectric material 6 and a source electrode 7; a drain electrode 8; and a gate 9.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are only some embodiments, but not all embodiments, of the present invention. All other embodiments, which can be obtained by a person skilled in the art based on the embodiments of the present invention without any creative effort, belong to the protection scope of the present invention.