铟镓砷与金属接触形貌异常分析和改进

对P型InGaAs半导体金属接触形貌进行了分析。采用磁控溅射法在P型InGaAs表面制作了不同厚度的金属膜,并在不同温度下进行合金,研究了合金温度和膜层厚度对接触形貌、比接触电阻率的影响。使用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对界面形貌进行了表征,结果表明金属-半导体界面空洞与合金温度有直接关系,在合金温度小于350℃时,界面处不会出现空洞,若合金温度超过此值,空洞逐渐出现,并且空洞数量会随着合金温度的升高而增加。金属膜层间相互扩散和器件的比接触电阻率与Ti层和Pt层的厚度有关。通过优化合金工艺和金属膜层厚度改进了半导体与金属接触形貌,金属间界面清晰无相互扩散,降低了器件比接触电阻率和常态温度下的失效率(FIT)。

Analysis and Improvement of the InGaAs-Metal Film Interface Abnormal Morphology

The contact morphology of P-InGaAs and metal was analyzed.Different thickness metal films were deposited on P-InGaAs by magnetron sputtering,and alloyed at different temperatures.Alloying temperature and thickness of film were analyzed.Scanning electron microscope(SEM)and transmission electron microscope(TEM)were used to characterize the contact morphology,the results show that the voids is directly to alloy temperature.When alloying is under 350℃,the voids will not appear,otherwise,the voids will appear gradually,and the density of voids will increase with the increase of the temperature.The diffusion between metal films and contact resistivity are related to the thickness of Ti and Pt.By optimizing the alloying and thickness of metal film,the contact morphology between semiconductor and metal is improved,the interface between metals is clear without diffusion,and the specific contact resistivity and failure-instance/time(FIT)of devices are decreased.