基于CMOS工艺的横向多晶硅p^＋p^-n^＋结红外微测辐射热计

基于多晶硅p-n结正向压降的温度特性,应用标准CMOS工艺,结合体硅微机械加工技术,研制成功非制冷红外微测辐射热计.本文详细分析了横向多晶硅p+p-n+结的温度特性,给出了正向压降温度变化率的理论表达式和实验测量值;并描述了微测辐射热计的设计思路和制作工艺.实验结果表明在室温(284～253K)附近,横向多晶硅p+p-n+结正向压降的温度变化率为1.5mV/K;在3～5μm红外波段,微测辐射热计的电压响应率为5.7×103V/W,黑体探测率D*为1.2×108cm.Hz1/2.W-1.     

横向多晶硅p+p-n+结非致冷红外焦平面

应用标准CMOS工艺,同时结合体硅微机械加工技术,研制成功横向多晶硅p p-n 微测辐射热计单元;基于研制成功的微测辐射热计,设计了规模为128×128面阵的非致冷红外焦平面.采用标准CMOS工艺制作横向多晶硅p p-n 结热敏响应元和读出电路;在CMOS工艺完成后,辅以与CMOS工艺兼容的体硅微机械加工工艺,制备微桥形式的热绝缘结构,从而方便地实现了CMOS读出电路与探测器阵列的单片集成.在3～5 μm红外波段,微测辐射热计的电压响应率为5.7×103 V/W,黑体探测率D·为1.2×108 cm·Hz1/2·W-1.焦平面采用行读出模式的结构,信号读出采用栅调制积分电路,输出级采用外接负载电阻的源极跟随电路,将探测器单元产生的信号按顺序串行单端输出.     

微测辐射热计的建模与仿真

微测辐射热计是一种应用前景广阔的非制冷型红外焦平面器件,本文对微测辐射热计 进行了建模和仿真,并利用该模型分析、仿真了复位积分放大器CTIA (Capacitive Transimpedance Amp lifier)输出的微测辐射热计对不同黑体目标的输出电压和像元的响应率,为进一步设计、优化微测辐射热计读出电路打下了基础。     

非晶硅室温微测辐射热计的研制

将聚酰亚胺作为绝热材料,对传统室温微测辐射热计结构进行了改进,成功制备了非晶硅室温微测辐射热计并进行了测试。以聚合物材料作为绝热材料,避免了表面牺牲层工艺和体加工技术,降低了成本、提高了成品率。在传统探测器结构基础上,在底部制备一层金属用作红外反射层,利用吸收层可以对红外辐射进行二次吸收。金属层和有源层间的隔离层对红外也有很好的吸收效果,由隔离层、有源层和钝化层构成三明治结构,可以显著改善对红外辐射的吸收。对器件的制备工艺进行了说明并对器件特性进行了测试,结果表明,在773 K黑体源8～14 μm红外辐射下,探测器的响应度最大为26.4 kV/W,表明器件具有较高的性能。     

基于有限元法的微测辐射热计热电性能研究

采用有限元法针对微测辐射热计的热电耦合敏感机理进行研究.建立微测辐射热计精确三维有限元模型,采用动态热电有限元方法对器件的热电特性进行了分析,得到了其热电耦合场下的温度响应特性,并获取其热容、有效热时间常数和有效热导值等热学参数;采用该方法在微测辐射热计的设计阶段中,即可初步预判器件性能并为器件制备提供可靠的参考.所设计结构经流片验证,性能良好,且满足60 Hz帧频成像要求.     

双牺牲层微测辐射热计最新研究进展

通过改善结构,来研制更小尺寸、更高分辨率的器件,成为微测辐射热计研制的新趋势,而其中最普遍的做法就是使用双牺牲层.本文介绍了双牺牲层微测辐射热计研究的最新成果,即以Raytheon和DRS等为代表的两种做法,并从器件结构和工艺上比较了两种思路的优劣.     

多晶锗硅室温微测辐射热计线性阵列的研制

采用超高真空气相淀积系统 ( UHVCVD)制备了多晶锗硅薄膜 ( poly-Si0 .7Ge0 .3) ,研究了它的退火特性和电阻温度特性。将多晶锗硅薄膜电阻作为微测辐射热计的敏感元件 ,采用体硅微机械加工技术制作了 8× 1桥式微测辐射热计线性阵列 ,优化设计的微桥由两臂支撑 ,支撑臂的长和宽分别为 2 2 0 μm和 8μm,桥面面积为 80μm× 80μm。测试结果表明 ,在 773 K黑体源 8～ 1 4μm红外辐射下 ,调制频率为 3 0 Hz时 ,阵列中各单元的电压响应率为 6.2 3 k V/W～ 6.40 k V/W,探测率为 2 .2 4× 1 0 8cm Hz1 /2 W- 1～ 2 .3 3× 1 0 8cm Hz1 /2 W- 1 ,热响应时间为2 1 .2 ms～ 2 2 .1 ms,表明了器件具有较高的性能及较好的一致性。     

用于测辐射热计热敏材料的多晶锗硅薄膜的研究

根据测辐射热计对热敏感材料的要求,采用超高真空化学气相淀积(UHVCVD)法制备出多晶Si0.7Ge0.3薄膜,研究了B离子注入剂量、退火工艺与电导率和电阻温度特性的相关性,因此确定出了最佳的工艺条件,并利用其制备出了探测率高达3.75×108cmHz1/2.W-1的测辐射热计。     

射频磁控溅射氧化钒薄膜的结构与性能研究(英文)

以非制冷微测辐射热计型红外探测器应用为需求背景,采用射频磁控溅射技术在300℃低温条件下制备了氧化钒薄膜。采用X射线衍射(XRD)、原子力显微镜(AFM)、能量色散谱(EDS)及X射线光电子能谱(XPS)技术表征了薄膜的结晶状态、微观结构与化学组成。采用四探针技术研究了薄膜的电学性能。结果表明该薄膜主要为非晶态的二氧化钒(VO2),并具有光滑的表面形貌。这种非晶VO2薄膜在22～100℃温度范围内不存在半导体-金属相变。100 nm厚的非晶VO2薄膜室温下的面电阻为600 kΩ/□,同时表现出-2.1%/℃的较高电阻温度系数(TCR),这表明该薄膜有希望用于非制冷微测辐射热计型红外探测器。     

日本研制出性能远好于普通测辐射热计的远红外量子探测器

日本东京大学的一个研究小组已研制出一种利用掺杂AlGaAs/GaAs异质结中的二维电子回旋共振的远红外光学探测器。该器件用一种叫做霍耳条(Hallbar)的结构制备,其在4.2K时的响应率为1.1×10~7V/W,比市场上出售的测辐射热计高1000倍。峰值探测率达     

Determination of Thermal Parameters of Vanadium Oxide Uncooled Microbolometer Infrared Detector

Vanadium oxide thin films are the potential candidates for uncooled microbolometers due to their high temperature coefficient of resistance (TCR) at room temperature. A 2D array of 10-element test microbolometer without air-gap thermal isolation structure was fabricated with pulsed laser deposited vanadium oxide as IR sensing layer for the first time. Infrared responsivity of the uncooled microbolometer was evaluated in the spectral region 8-15 μm. The device exhibits responsivity of about 12 V/W at 30 Hz chopper frequency for 20 μA bias current. Thermal time constant (τ), Thermal conductance (G) and thermal capacitance (C) are the thermal parameters characterize the performance of the uncooled microbolometer infrared detectors are determined as 15 ms, ～10^-3 W/K and ～3.5 × 10^-5 J/K respectively. The influence of the thermal parameters on the performance of the microbolometer is discussed.     

Micromachined Uncooled IR Bolometer Linear Array Using VO2 Thin Films

Mixed vanadium oxide thin films, as VO₂ for the main composition are materials for uncooled microbolometer due to their high temperature coefficient of resistance (TCR) at room temperature. This paper describes the design and fabrication of 8-element linear array IR uncooled microbolometers using the films and micromachining technology. The characteristics of the array is investigated in the spectral region of 8–12 μm. The fabricated detectors exhibit responsivity of up to 10 KV/W, typical detectivity of 1.89×10⁸ cmHz^1/2/W, and thermal time constant of 11 ms, at 296 K and at a frequency of 30 Hz. Furthermore, The uncorrected response uniformity of the linear array bolometers is less than 20%.     

基于VO2薄膜非致冷红外探测器性能研究

用微电子工艺制备了VO     

Study on new structure uncooled a-Si microbolometer for infrared detection

A new structure uncooled amorphous silicon (a-Si) microbolometer for infrared (IR) detection has been fabricated and characterized. New type of thermal isolation and IR absorption structures based on polyimide (PI) and bottom metal reflective layer are presented. The fabrication process is described in this paper. The as-prepared microbolometer has the advantage of low cost, high yield and moderate performance. The dependence of resistance with different aspect ratio on operating temperature has been investigated and the temperature coefficient of resistance (TCR) is achieved. Based on the measured responsivity and noise characteristics, the influence of detectivity on chopping frequency is discussed. According to the measurements and calculations results, the maximal TCR is −2.8% and at a bias voltage of 5 V, the maximum detectivity of 1.7×10⁸ cm Hz^1/2 W⁻¹ is achieved at chopping frequency of 30 Hz.     

Thermal budget calculations, design aspects, and device performanceof high-Tc air-bridged microbolometers

The thermal properties of an air-bridged microbolometer have been evaluated on the basis of a finite element calculation scheme for the first time. The numerical results show that the performance of the device's sensitively depends on geometry and layout. The degree of thermal coupling and interaction with the heat sink affects the thermal time constant and frequency range of operation. For identical geometries, experimental and modeled data are in good agreement. The length of the air-bridge is defining the effective thermal time constant but has little effect on the thermal responsivity. An unusually high responsivity has been calculated for configurations where the thermal coupling to the heat sink has been minimized. This design leads to an increase of responsivity of a factor of 200 and would establish superior operation of the device even at ambient temperature     

Fabricating Microbolometer Array on Unplanar Readout Integrated Circuit

In this paper, the integration of an experimental 32 × 32 uncooled IR microbolometer array with an unplanar CMOS Readout Integrated Circuit (ROIC) is presented. A vanadium oxide film fabricated by low temperature reactive ion beam sputtering is utilized as thermal-sensitive material in the bolometric detectors Before the integration, the unplanar ROIC for commercial use is first planarized by bisbenzocyclobutene film, then a electroless nickel-plating on ohmic contact areas is accomplished. Finally the bolometer array is fabricated using a micromachining process, which is completely compatible with CMOS technology. Measurements and calculations for the as-fabricated samples show that the responsivity of 1.4 × 10⁴ V/W and the detectivity of 2.1 × 10⁸cmHz^1/2W^?1 and a thermal response time of 10ms are obtained at a pulse bias of IV.     

非制冷微测辐射热计的特性参数

描述了非制微测辐射热计的电热效应,推导了响应率、噪声、噪声等效功率、噪声等效温差、探测率等特性参数的计算公式,结果表明,电热效应是影响微测辐射热计性能的关键因素之一。     

Microheater and microbolometer using microbridge of SiO2 film on silicon

Microbridges of SiO2 film, with a vacant space introduced by Si etching beneath each of them, are fabricated. As applications of the microbridge, Pt microheaters and Bi or Te microbolometers are made. These microheaters are able to heat up to over 800°C and have a thermal time constant ? of about 200 ?s. At microbolometer with the same size microbridge as that of the microheater is estimated to have a responsivity Rs, and NEP of about 47 V/W and 6.47×10?11 WHz? in a Bi bolometer, and of about 130 V/W and 7.8×10?11 WHz? in a Te bolometer, and ? of about 300 ?s, as determined by an illumination experiment using a HeNe laser.