Abstract
We propose a new HfGeOx interfacial layer (IL) for the high-κ gate-stacks on p-Type germanium substrate with improved thermal stability as compared with that of conventional GeOx IL. We inserted an additional HfO 2 layer after the formation of GeO x in the HfO 2 /Al 2 O 3 /GeOx/Ge gate-stack by using plasma-enhanced atomic layer deposition. Through the use of post-deposition annealing and post-metal annealing, the new system exhibited greater thermal immunity and was stable up to 600 °C. We speculate that the improvement originates from the formation of HfGeO x through the combination of HfO 2 and GeO x , according to the thermodynamic data. By incorporating Hf into interfacial layer, the fabricated high-κ gate-stack with an equivalent oxide thickness of 1.2 nm, a low interface states density (Dit) of approximately 3.3×10 11 eV -1 cm -2 , and an impressive gate leakage current of approximately 2.2×10 -6 A/cm 2 at V FBs -1V.
Original language | English |
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Article number | 7577750 |
Pages (from-to) | 1379-1382 |
Number of pages | 4 |
Journal | IEEE Electron Device Letters |
Volume | 37 |
Issue number | 11 |
DOIs | |
State | Published - 1 Nov 2016 |
Keywords
- Aluminum oxide (Al O )
- Equivalent oxide thickness
- Germanium
- Germanium oxide (GEO )
- Hafnium oxide (HfO )
- Plasma enhanced atomic layer deposition