Research Of Preparation Technology Of Infrared Detector Based On Lithium Tantalate Crystal

Pyroelectric infrared which is a receiving device to use the pyroelectric effect of somematerials to detect infrared radiation is one of the heat detector and a new type of heatdetector made significant progress since the70s. The study of pyroelectric infrared detectorhas experienced more than a century of time. It is widely used in military, industrial, medical,space technology, and environmental monitoring and other fields because of its advantages oflow price, light weight, wide spectral response degree, fast response speed, non refrigerationat room temperature, easy to imaging and high cost performance so that it become the currenthot topic in the field of infrared technology. Lithium tantalate material which has highdetection optimal value, high Curie temperature of665℃, easy processing, high strength ofmaterials and easying implement thickness, strong ability to resist the influence of theexternal environment and light heat loss is an ideal material in preparation of pyroelectricinfrared detector. Lithium tantalate material is regarded as the sensitive material and there areresearch of preparation technology、completed the preparation of detector、the shell designand responsive current test under different frequency in content of the article.In the preparation process we optioned out A feasible preparation technology bycomparing three different technology.The detector whose substrate is made of SU-8-2010rubber，which is made of simplepreparation technology, mechanical strength and superior performance，is main highlight.Film, lithography and grinding process involved in probe preparation process have beenstudied respectively.(1) In film process,the relationship between film deposition rate and each processparameters such as work pressure, sputtering power is studied.The experimental results showthat an optimum value，which improve the utilization of target material and argon gas, exists in the relationship between working pressure and the film deposition rate. The filmdeposition rate increases gradually with the increasing of sputtering power.(2) In lithography process, process parameters of every step which have direct influenceon lithography quality should be strictly controlled. A set of ideal process parameters wereobtained after some experiments.(3)In the grinding process, relationship between thinning quality and each processparameter such as Grinding speed, thinning thickness value,abrasive grinding fluid shape andparticle size must be analyzed. Effect that the thickness uniformity of the crystal surface haveon detector performance after grinding is analyzed comprehensively.Finally, the detector encapsulation shell is designed and test system of detector responsesignal was built according to the laboratory existing conditions. Response signals, whichshow that the response signal amplitude decreases with the increase of frequency,of differentfrequency radiation and Certain v value were measured in this test system. Two reasons havebeen contributed to above phenomenon: one is the low pass filter. Other is that lithiumtantalate wafer area is larger, the heat capacity is larger.