Pt:Ti Diffusion Barrier, Interconnect, and Simultaneous Ohmic Contacts to n- and p-Type 4H-SiC
Pt:Ti Diffusion Barrier, Interconnect, and Simultaneous Ohmic Contacts to n- and p-Type 4H-SiC
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DOI：
10.4028/www.scientific.net/msf.924.381
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发表时间：
2018-06
期刊：
影响因子：
--
通讯作者：
R. Okojie;D. Lukco
中科院分区：
文献类型：
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作者：
R. Okojie;D. Lukco
我们报道了用共溅射的Pt：Ti80：20At的初步结果。%成分比金属化，作为金(Au)和氧(O)的扩散屏障，作为互连层，以及同时与n型和p型4H-SiC形成欧姆接触。具有这种组合多功能属性的单个导体将显著降低制造基于碳化硅的器件所固有的制造成本、处理时间和复杂性。俄歇电子能谱、聚焦离子束辅助场发射扫描电子显微镜和能谱分析表明，在800℃的大气中暴露15分钟后，Au和O没有迁移到碳化硅接触表面，并通过铂：钛势垒层进行了微小的扩散，从而提供了欧姆接触的潜在长期稳定性。在n(Na=7×10~(-18)cm~(-3))和p(Na=2×10~(20)cm~(-3))型4H-碳化硅上的比接触阻值分别为7×10~(-5)和7.4×10~(-4)Ω·cm~2。对于夹在两个二氧化硅层之间的铂：钛层，获得了75μΩ-cm的电阻率，并在高达900°C的纯氧环境中进行了热处理，这为高温互连金属化提供了希望。
We report the initial results of using co-sputtered Pt:Ti 80:20 at. % composition ratio metallization as a diffusion barrier against gold (Au) and oxygen (O), as an interconnect layer, as well as forming simultaneous ohmic contacts to n-and p-type 4H-SiC. Having a single conductor with such combined multi-functional attributes would appreciably reduce the fabrication costs, processing time and complexity that are inherent in the production of SiC based devices. Auger Electron Spectroscopy, Focused Ion Beam-assisted Field Emission Scanning Electron Microscopy and Energy Dispersive Spectroscopy analyses revealed no Au and O migration to the SiC contact surface and minimal diffusion through the Pt:Ti barrier layer after 15 minutes of exposure at 800 oC in atmosphere, thus offering potential long term stability of the ohmic contacts. Specific contact resistance values of 7 x 10-5 and 7.4 x 10-4 Ω-cm2 were obtained on the n (Nd=7 x 1018 cm-3) and p (Na=2 x 1020 cm-3) -type 4H-SiC, respectively. The resistivity of 75 μΩ-cm was obtained for the Pt:Ti layer that was sandwiched between two SiO2 layers and annealed in pure O ambient up to 900 °C, which offers promise as a high temperature interconnect metallization.