本工作通过采用电化学极 -化学氧化两步法在 1:1氢氟酸和乙醇溶液中制备出孔径约为 1～ 2 μm ,厚度大经为 6～ 10 μm的多孔硅样品 .首先将 0 .0 3A/cm2 的恒电流施加到p( 10 0 )硅片一段时间 ,然后将该硅片浸到 2 0 %的硝酸溶液中氧化一段时间 .通过此方法获得的多孔硅结构再进一步用扫描电子显微镜和拉曼光谱仪进行表面形貌和光学性质的考察 .所有制备出的多孔硅结构均有光致发光现象 .老化的多孔硅样品 (在干燥器放置一年 )的光致发光谱峰强度明显增强 ,但分别经过苯乙烯和十六碳烯 ( 1)两种有机溶剂处理 1h后的老化多孔硅样品的光致发光强度却没有显著改变 .
Porous silicon structures were formed by a two step technique consisting of electrochemical polarization and chemical oxidation processes in 1∶1 hydrofluoric acid and ethanol solutions. A constant current density of 0.03 A/cm 2 was applied to p type silicon wafers, followed by chemical treatment in 20% nitric acid solutions. These samples were then carefully examined by scanning electron microscope (SEM) and Raman spectrometer to study their surface morphologies and optical properties. After a year storage in a desiccator, the aged porous silicon samples were re examined by SEM and Raman spectrometer before and after treated with styrene and decene(1) organic solvents, respectively. It was found that the Raman intensities of the aged porous silicon samples were significantly enhanced. However, the treatments of the aged porous silicon samples with tow organic solvents did not alter their optical properties.
[1] CanhamLT .Siliconquantumwirearrayfabricationbyelectrochemicalandchemicaldissolutionofwafers[J].Appl.Phys.Lett .,1990 ,57( 10 ) :10 4 6～ 10 4 8.
[2 ] BrandtMS ,FuchsHD ,StutzmannM ,etal.Theoriginofvisibleluminescencefrom“poroussilicon” :anewinterpretation[J].SolidStateCommun .,1992 ,81( 4 ) ,30 7～ 312 .
[3] ProkesSM ,GlembockiOJ ,BermudezVM ,etal.SiHxexcitation :analteratemechanismforporousSiphotoluminescence[J].Phys.Rev .,1992 ,B 4 5( 2 3) :13788～ 13791.
[4 ] ProkesSM .Lightemissioninthermallyoxidizedporoussilicon :evidenceforoxide relatedluminescence[J].Appl.Phys .Lett .,1993,62 ( 2 5) :32 4 4～ 32 4 6.
[5] ProkesSM ,GlembockiOJ .Roleofinterfacialoxide relateddefectsinthered lightemissioninporoussilicon[J].Phys .Rev .,1994 ,B4 9( 3) :2 2 38～ 2 2 4 1.
[6] LiKH ,TsaiC ,SarathyJ ,etal.Chemicallyinducedshiftsinthephotoluminescencespectraofporoussilicon[J].Appl.Phys.Lett .,1993,62 ( 2 4 ) :3192～ 3194 .
[7] LauerhaasJM ,CredoGM ,HeinrichJL ,etal.ReversibleluminescencequenchingofporousSibysolvents[J].J .Am .Chem .Soc .,1992 ,114( 5) :1991～ 1912 .
