High Performance Ge pMOSFETs With HfO 2 /Hf-Cap/GeO x Gate Stack and Suitable Post Metal Annealing Treatments
2017; Institute of Electrical and Electronics Engineers; Volume: 38; Issue: 5 Linguagem: Inglês
10.1109/led.2017.2686400
ISSN1558-0563
AutoresShih-Han Yi, Kuei‐Shu Chang‐Liao, Tzung-Yu Wu, Chia‐Wei Hsu, Jiayi Huang,
Tópico(s)Ferroelectric and Negative Capacitance Devices
ResumoAn equivalent oxide thickness of ~0.53 nm, gate leakage current density of ~10 -4 A/cm 2 at V FB + 1 V, I ON /I OFF ratio of 10 4 , subthreshold swing of 136 mV/dec, and peak hole mobility of 375 cm 2 /V-s at N inv = 1.6 × 10 12 cm -2 in Ge p-type metal-oxide-semiconductor-field-effect transistors (pMOSFETs) are achieved by HfO 2 /Hf-cap/GeO x gate stack with suitable post-metal-annealing (PMA) treatments. Such a high mobility in Ge pMOSFETs can be attributed to an ultrathin GeOx layer at the surface of Ge substrate. Ge +1 and Ge +2 in GeO x layer are re-oxidized to higher oxidation state by gettered oxygen, which is captured by Hf-cap from GeO x and HfO 2 during PMA. The minimized contents of Ge +1 and Ge +2 in GeO x are crucial to achieve excellent electrical characteristics.
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