Metal-Semiconductor Contacts for Sensor Application

用于传感器应用的金属-半导体触点

• 批准号: 01460138
• 负责人: ITO Kentaro
• 金额: $ 4.22万
• 依托单位: Shinshu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01460138/
• 关键词: anodization; semiconducting oxide; hydrated tungsten oxide; metal-semiconductor contacts; hydrogen sensor; PTC effect; 水和酸化タングステン; 着色機構; 陽極酸化膜; 同位体効果; 反射率; 水素タングステンブロンズ; プロトンの拡散; 応答時間; 酸化物半導体; 酸化タングステン; 水素クロミズム; 光学密度; 凝結水; Pd薄膜; 金属-半導体

We have investigated metal-semiconducting oxide contacts to develop a highly selective and sensitive hydrogen detector and a positive temperature coefficient (PTC) thermistor. Our purpose in this research is to elucidate fundamental mechanisms for these sensors and optimize process parameters of the device fabrications.We have found that a forward current of the diode consisting of Pd thin film and semiconducting Sr_xBa_<1-x>TiO_3 ceramics increases on exposure to hydrogen. The barrier height depends on hydrogen concentration in the same way as that of a Pd MOS structure. The reverse currents of Au/anodic oxide/ barium strontium titanate ceramics structure shows the PTC effect and voltage dependence which follows the Fowler-Nordheim equation.A transmission-type hydrogen sensor is fabricated by using a sputtered amorphous tungsten oxide film which is deposited on the glass substrate and then covered with semitransparent Pd thin film. A decrease in the spectral transmittance by hydrogen has a peak at the wavelength of 900 nm. The response time of the sensor is of the order of 10^2 s. Though the hydrogen sensitivity is considerably degraded after annealing at 200 ﾟC in vacuum, the sensor partially recovers the initial response time after subsequent exposure to water vapor at 100 ﾟC and aging in room air.A reflection-type hydrogen sensor consists of an anodic oxide film formed on the W sheet and then covered with semitransparent Pd or Pt film. Its response time is of the order of 10 s. It is revealed by X-ray diffraction that the film consists of WO^3・H^2O. Coloration mechanism for the sensor is considered to be based on formation of hydrogen tungsten bronzes and a consequent increase in electron concentration of the film. A rate determining step of the coloration reaction is probably due to water-assisted proton diffusion. The best processes for polishing and anodizing the W sheet are also presented.

我们已经研究了金属 - 氧化物接触，以开发高度选择性和敏感的氢检测器和正温度系数（PTC）热水瓶。我们在这项研究中的目的是阐明这些传感器的基本机制，并优化设备制造的过程参数。我们发现，由PD薄膜和半导体组成的二极管的正向电流和半导体SR_XBA_ <1x> TIO_3陶瓷在暴露于氢气的情况下增加。与PD MOS结构相同的方式，屏障高度取决于氢浓度。 Au/ Au/ Anodic氧化物/芳族氧化镁锶陶瓷结构的反向电流显示了PTC效应和电压依赖性，后者遵循Fowler-Nordheim方程。通过使用溅射的无晶型氧化氧化物薄膜和玻璃胶片覆盖的薄薄膜，制造了一种传输型氢传感器。氢的光谱传输减少在900 nm的波长下具有峰值。传感器的响应时间为10^2 s。 Though the hydrogen sensitivity is considered degraded after annealing at 200 ﾟC in vacuum, the sensor partially recovers the initial response time after subsequent exposure to water vapor at 100 ﾟC and aging in room air.A reflection-type hydrogen sensor consists of an anodic Oxide film formed on the W sheet and then covered with semitransparent Pd or Pt film.它的响应时间为10 s。 X射线衍射揭示了该薄膜由WO^3 h^2o组成。传感器的着色机制被认为是基于形成氢钨青铜的形成和膜电子浓度的增加。确定颜色反应步骤的速率可能是由于水辅助质子扩散所致。还提供了抛光和阳极氧化W板的最佳过程。

项目成果

K. Takahashi and K. Ito.: "Principles od Sensors" The Institute of Electrical Engineers of Japan. 1-215 (1990)

K. Takahashi 和 K. Ito.：“传感器原理”日本电气工程师协会。

高橋 清: "基礎センサ工学" 電気学会, 215 (1990)

高桥清：《传感器工程基础》日本电气工程师学会，215（1990）

K.Ito,T.Ohgami,T.Nakazawa: "Effect of water on hydrogen-sensitive tungsten oxide films" Sensors and Actuators.

K.Ito、T.Ohgami、T.Nakazawa：“水对氢敏感氧化钨薄膜的影响”传感器和执行器。

Kentaro Ito: "Positive temperature coefficient of resistance in metal-semiconductor contacts" J.Applied Physics. 65. 1982-1986 (1989)

Kentaro Ito：“金属-半导体接触中的正电阻温度系数”J.应用物理学。

K,Ito,T.Ohgami,T.Nazawa: "Effect of water on hydrogenーsensitive tungsten oxide films" Sensors and Actuators.

K、Ito、T. Ohgami、T. Nazawa：“水对氢敏感氧化钨薄膜的影响”传感器和执行器。