采用电化学直流极化和交流阻抗技术 ,在有光照和黑暗条件下分别研究了半导体硅片在稀释氢氟酸溶液中的电化学特性 .两种电化学技术均对溶液中含有的微量铜 (1 0 - 9wt % -浓度水平 )非常敏感 ,但仅对溶液中的 1 0 - 6 wt % -浓度水平的非离子型表面活性剂敏感 .结果表明 ,有光照条件下在硅 /溶液界面上极易发生电化学反应 ,且该反应对硅表面性质起主导作用 .
Electrochemical characteristics of semiconductor silicon wafers were investigated in dilute hydrofluoric acid solutions using DC polarization and AC impedance techniques under both illuminated and dark conditions. Both techniques were extremely sensitive to the trace amount (10 -9 wt% level) of copper presented in solutions, but only sensitive to the 10 -6 wt% level of non ionic surfactant OHS contained in solutions. The results revealed that the electrochemical reactions took place favorably and became predominated at silicon/solution interface under illuminated condition.
[1 ] KernW .SemiconductorSilicon[A].S .J .Moss ,A .Ledwith .TheChemistryoftheSemiconductorIndus try[C],1 970 ,1 7～ 40 .
[2 ] SzeS .M .PhysicsofSemiconductorDevices[M ].NewYork :JohnWiley&Sons,Inc .,1 981 .
[3] Lin ,P .S .D .,R .B .Marcus ,T .T .Sheng .LeakageandBreakdownOxideCapacitors CorrelationwithDecoratedStackingFaults[J].J .Electrochem .Soc .,1 983,1 30 (a) :1 878～ 1 883.
[4 ] TorcheuxL .,A .Mayeux ,M .Chemla .ElectrochemicalCouplingEffectsontheCorrosionofSiliconSamplesinHFSolutions[J].J .Electrochem .Soc .,1 987,1 42 (6 ) ,2 0 37～ 2 0 46 .
[5 ] KernW .RadichemicalStudyofSemiconductorSurfaceContamination ,II .DepositionofTraceImpuritiesonSiliconandSilica[J].RCAReview ,1 970 ,2 34～ 2 6 4.
[6 ] JeonJ .S .,RaghavanS .,ParksH .G .,etal.ElectrochemicalInvestigationofCopperContaminationonSiliconWafersfromHFSolutions[J].J .Electrochem .Soc .,1 996 ,1 43(9) ,2 870～ 2 875 .
[7] ChengX .,LinCJ .AnElectrochemicalImpedanceStudyofCopperDepositiononn typeSilicon[A].Pro ceedingsof 3rdChineseScientificAssociationYouthAnnualMeeting ,MaterialsScience&TechnologySec tion[C],1 998,1 78～ 1 81 (inChinese) .
