Magnetron Sputtering Preparation Pbte Films And Al Mixed Performance Research

As a very importantⅣ-Ⅵcompound semiconductor, PbTe has excellent photoelectric andthermoelectric characteristics, such as the high refractive index and the positive temperaturecoefficient of the gap，the large carrier mobility. Those unusual charaeteristies make PbTesemiconductor unique among polar compounds and have important application in many fields,such as infrared detectors, light-emitting devices and more recently as infrared laser in fiberoptics, thermoelectric materials, solar energy panel and window coatings. In this paper, we fromtwo aspects to study PbTe semiconductor material: first, we deposit PbTe films onto Si(111)substrate by magnetron sputtering and sutdy the effect of the process parameters on the PbTefilms of crystallization properties, optical transmission rate and electrical properties; second,Al-doped PbTe films were prepared by radio frequency magnetron sputtering and then annealedin the vacuum resistance furnace, the effect of annealing temperature and annealing time on thecharacteristics of Al/PbTe films were investigated. The main research results are as follows:1. We deposit PbTe films by magnetron sputtering at different experimental conditions and sutdythe effect of the sputtering power, substrate temperature, film thickness on crystallizationproperties, optical transmission rate and electrical properties of PbTe films. Research shows that:(1) PbTe thin films have strong (200) optimizing orientation direction prepared in differentpowers. With the increase of sputtering power, the preferred orientation of films graduallyimprove, transmission rate improve, resistivity reduce. We can obtain the best quality films at30W power condition.(2) From the study of PbTe thin films with different thicknesses prepared at the sameexperimental condition, we can conclued that film with 200nm thickness has the highesttransmission rate and minimum resistivity.(3) Among those PbTe thin films deposited at different deposition temperatures, the filmsprepared at room temperature have strongest (200) optimizing orientation direction. We can getthe highest transmission rate when the substrate temperature is 300℃, while, when the substrate temperature is 200℃, the resistance of PbTe film is the lowest.2. The Al-doped PbTe films were deposited onto Si substrate by radio frequency magnetronsputtering and then annealed in the vacuum resistance furnace. The effect of annealingtemperature and annealing time on the characteristics of Al/PbTe films were investigated.Itindicates that the annealing time and temperature have a great influence on the surfacemorphology, transmittance and resistivity of the Al/PbTe thin films.(1) The Al-doped PbTe thin films were annealed at 980℃conditions for different times, theexperimental result indicates that with the time of annealing extension , the height of PbTe(200)diffraction peak lower. On the surface of the samples flower shape gathers become more andmore intensive and evenly. The transmission rate and resistivity of The samples present a trendof decrease as the extension of annealing time.(2) All the samples annealed at different temperatures have obvious (200)directionoptimizing orientation; after annealed, the height of the diffraction peak (200) markedly reduced,some flower shape gathers appear on the surfaces of the specimens.with the annealingtemperature increases, flower shape gathers become more and more intensive and evenly. Thesample which annealed at 1173 K has the highest transmission rate and largest resistivity.