3种SiO2基无机驻极体材料STBR、SPAP及SiO2薄膜的性能对比与研究

Comparison and study of three kinds of SiO2 based inorganic electret materials: STBR, SPAP and SiO2 film

运用热氧化和高温熔凝工艺在轻掺中阻硅片(ρ=8~13Ω·cm)上制备了3种无机驻极体:SiO2薄膜、SiO2-Ta2O5-B2O3-RO复合材料(STBR)以及SiO2-PbO-Al2O3-P2O5复合材料(SPAP)。实验结果显示,STBR为微晶结构,其材料介电常数高达~2000级别,而SPAP为非晶态结构,其介电常数小于3。恒压电晕充电后所有材料均可以获得与栅压相近的表面电位并在室温下保持一定时间;TSD热刺激放电显示3种材料的电荷输运特性各不相同,其中SiO2薄膜的负电流峰位于T=295℃并随充电温度的提高而向高温区漂移,正电流峰则显示异常,总电流谱呈多峰结构;而STBR和SPAP材料的电流谱则均为单峰结构,正负对称,其中STBR的主峰位于T=240℃,而SPAP的主峰位于T=290℃,基本不随充电温度的变化而改变,显示出完全不同的驻电特性,这表明它们是两种新型的无机驻极体复合材料。

Three kinds of inorganic electret materials:SiO2-Ta2O5-B2O3-RO(STBR),SiO2-PbO-Al2O3-P2O5(SPAP)and SiO2 film have been achieved via high temperature sintering and thermal oxidation on lightly doped silicon wafer(ρ=8-13Ω·cm).The test results showed that the STBR was a micro-crystalline structure with its dielectric constant up to^2000,while the SPAP was an amorphous structure with its dielectric constant lower than 3.Each surface potential of these three materials was similar to the grid voltage after constant-voltage-charging and maintained some days at RT,but the thermally simulated discharge(TSD)showed that they have thoroughly different carrier transportation properties.The TSD spectrum of SiO2 film had a multiple peak structure with its negative main current peak located at T=295℃and drifted to high T area when the charging temperature was raised,while the positive one showed an anomaly.But the TSD spectrums of both STBR and SPAP were single-peak structure with fixedly location at T=240℃(STBR)or T=290℃(SPAP),and the negative and positive current peaks were about temperature axisymmetric and uninfluenced by the charging temperature.It could be concluded that the SiO2-Ta2O5-B2O3-RO and SiO2-PbO-Al2O3-P2O5 were two kinds of novel SiO2 based inorganic composite materials with totally different electret properties.