High Performance Ge Schottky PMOSFETs with Ternary-Phase Alloy

Chung-Chun Hsu, Wei-Chun Chi, Chen-Han Chou, Che-Wei Chen, Hung-Pin Chien, Chao-Hsin Chien*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

This work demonstrates high-performance Ge p-channel metal-oxide-semiconductor field-effect transistors (PMOSFETs) [1] with ternary-phase NiGePt alloy Schottky source/drain (S/D) by low-temperature microwave-activated annealing (MWA) [2]. Process flow of Shcottky junctions is shown in Fig. 1. Interestingly, the formed NiGePt alloy is nearly single crystalline. We found the formation of ternary-phase alloy NiGePt seems very helpful in suppressing the off-leakage of junction, as shown in Fig. 2. The fabricated NiGePt/N-Ge Schottky junction depicted an impressive effective barrier height (Phi(Bn)) of similar to 0.59 eV for electrons, leading to a high junction current ratio of >10(5) at the applied voltage of vertical bar V-a vertical bar = 1 V. Slight increase with increasing deposited Pt thickness can be explained by the improved series resistance, as shown in Fig. 2. The lower process temperature of MWA as compared to the conventional thermal annealing is beneficial for eliminating surface roughness, reducing alloy agglomeration of Schottky contact S/D. As a consequence, we employed the advantages of low-temperature MWA to fabricate the Schottky S/D PMOSFETs. With forming gas annealing, the Ge PMOSFET (L = 4 mu m) showed a very high output current of 33.5 mu A/mu m at V-GS-V-T = -2.4 and V-DS = -2 V. Our ternary Schottky PMOSFET exhibited a high I-ON/I-OFF ratios of similar to 3.7 X 10(3)(I-D) and similar to 1.3 X 10(5)(I-S), and a moderate subthreshold swing of 126 mV/dec, as shown in Figs. 3.

Original languageEnglish
Title of host publication2016 13th IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT)
EditorsYL Jiang, TA Tang, R Huang
PublisherIEEE
Pages304-305
Number of pages2
DOIs
StatePublished - Oct 2016
Event13th IEEE International Conference on Solid-State and Integrated-Circuit Technology (ICSICT) - Hangzhou
Duration: 25 Oct 201628 Oct 2016

Conference

Conference13th IEEE International Conference on Solid-State and Integrated-Circuit Technology (ICSICT)
CityHangzhou
Period25/10/1628/10/16

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