硅薄膜的pecvd制备及其结构研究

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1、河北工业大学硕士学位论文硅薄膜的PECVD制备及其结构研究摘要本文详细论述了PECVD法制备非晶硅和微晶硅薄膜的原理和过程，深刻剖析了PECVD仪器各部分的工作原理并进行了图示。实验选用SiH4和H2作为气源，在普通玻璃衬底上低温沉积了硅薄膜。制备的工艺参数范围如下，沉积温度：250-450℃；SiH4气-4体流量：1-40SCCM；放电功率：40-130W；本底真空度：6.6×10Pa；沉积气压：100Pa；沉积时间：30-540min。采用Raman散射谱、扫描电子显微镜(SEM)、透射电镜（TEM）、X射线衍射仪（

2、XRD）等手段研究了硅烷浓度、沉积温度、射频功率等参数对硅薄膜的结构、结晶状态和沉积速率的影响。实验结果表明，当硅烷含量由10%降低到1%过程中，Si薄膜沉积速率逐渐下降；-1当硅烷浓度降到2%时，拉曼光谱检测到对应的晶体Si在520cm附近的新吸收峰，而最-1初在480cm附近的非晶吸收峰位逐渐减弱，Si薄膜的结构实现了由非晶向微晶转变；当硅烷浓度降低到1%，晶化率提高到18%。随着沉积温度的升高，沉积速率不断提高，由250℃的163nm/h增长为350℃时的197nm/h。当射频功率由40W提升到70W时，沉积速率从

3、177nm/h升高到203nm/h，继续提升功率时沉积速率增长放缓，当射频功率超过100W后沉积速率趋于稳定。薄膜的厚度随沉积时间的增加而线性增长。关键词：硅薄膜，PECVD，结构，晶化，拉曼光谱i硅薄膜的PECVD制备及其结构研究STRUCTUREANALYSISOFSILICONFILMSDEPOSITEDBYPLASMAENHANCEDCHEMICALVAPORDEPOSITIONABSTRACTTheessaydissertatesthetheoryandtheprocessofthemanufactureofa

4、-Si:Handμc-Si:HbytheusageofPECVDandillustratestheworkingprinciplesofPECVD.SiliconthinfilmsaredepositedonglasssubstratesatlowtemperatureusingSiH4andH2ashydrogenandSisources.Thetechnicalconditionisasfollows,depositiontemperature:250-350℃,SiH4-4flux:1-40sccm,dischar

5、gepower:40-130W,vacuumlevel:6.6×10Pa,depositionpressure:100Pa,depositiontime:30-540min.Usingthemethodsuchasramanscatteringspectra,scanningelectronmicroscope(SEM),transmissionelectronmicroscope(TEM),x-raydiffraction(XRD)tostudydifferentpreparationtechniquessuchass

6、ilaneconcentration,substratetemperature,dischargepower'sinfluencetothesiliconthinfilm'sstructure,crystallinestateanddepositionrate.Itindicatedthatthedepositionrateofsiliconthinfilmsdecreasedgraduallywhensilaneconcentrationdeclinedfrom10%to1%.WhenSC(silaneconcentr

7、ation)movedto2%,thenew-1absorptionpeakofcrystalsiliconwhichneared520cmwasdetectedandtheinitialabsorption-1peakofamorphouswhichneared480cmwasgraduallyweakened.Thestructureofthesiliconthinfilmschangedgraduallyfromamorphoustomicrocrystalline.WhenSCturnedto1%,crystal

8、lizationratioincreasedto18%.Thedepositionrateofsiliconthinfilmsincreasedgraduallywiththeascendingtemperature.Itchangedfrom205nm/hat163℃to197nm/hat350℃.WhenRFpo