用弹道电子发射显微术研究超薄金属硅化物/硅肖特基接触

采用弹道电子发射显微术 ( BEEM)技术对超薄 Pt Si/Si、Co Si2 /Si肖特基接触特性进行了研究 ,并与电流 -电压 ( I- V)及电容 -电压 ( C- V)测试结果进行了对比 .研究了 Ar离子轰击对超薄Pt Si/n- Si肖特基接触特性的影响 .BEEM、I- V/C- V技术对多种样品的研究结果表明 ,I- V/C- V测试会由于超薄硅化物层串联电阻的影响而使测试结果产生严重误差 ;BEEM测试则不受影响 .随着离子轰击能量增大 ,肖特基势垒高度降低 ,且其不均匀性也越大 .用 BEEM和变温 I- V对超薄 Co Si2 /n- Si肖特基二极管的研究结果表明 ,变温 I- V测试可在一定程度上获得肖特基势垒

Ultra-Thin Metal-Silicide/Si Schottky Contacts Studied by Ballistic Electron Emission Microscopy

Ballistic Electron Emission Microscopy (BEEM) is a novel technique to study metal/semiconductor interface. The BEEM technique was used to study ultra|thin PtSi/Si, CoSi 2/Si Schottky contacts. The results are compared with those from current voltage ( I V ) and capacitance voltage ( C V ) techniques. For ultra|thin PtSi/n|Si diodes, the Si substrate is bombarded by Ar++ ions with different energy before metal deposition. The BEEM, I V/C V measurements of ultra|thin PtSi/n|Si diodes show that I V/C V results are strongly influenced by the considerable series resistance of the ultra thin silicide layer; while the BEEM measurement will not and the true Schottky contact properties can be obtained. BEEM results show that the Schottky barrier height of PtSi/n|Si decreases with the increase of the Ar++ ion bombardment energy. BEEM and variable temperature I V measurements of an ultra|thin CoSi 2/n|Si Schottky diode show that Schottky barrier inhomogeneity can be inferred from variable|temperature I V results and depends on the model for the barrier height distribution; on the contrary a Schottky barrier height distribution can be obtained directly by BEEM technique. The distribution of SBH is nearly Guassian.