This letter reports on the impact of gate microstructure on deep-submicron complementary metal-oxide-semiconductor (CMOS) device performance. Transistors with different gate microstructures (α-Si gate vs poly-Si gate) were fabricated using a 2.5 V sub-0.25 μm CMOS process and their performances were compared. The α-Si gate provides better capability for suppressing boron penetration in p-channel metal-oxide-semiconductor field-effect transistors (MOSFET's), but the depletion effect is more severe than that of the poly-Si gate. A modified gate doping (MGD) effect, in which the difference of linear transconductance (g m ) between transistors with two different gate microstructures shows a strong gate-length dependence, is reported for the first time and evaluated by the impact of grain boundary segregation on the electrically activated gate impurity density. The MGD effect makes the poly-Si gate more advantageous in the design of high-performance CMOS transistors with gate critical lengths shorter than 0.25 μm.
|Journal||Japanese Journal of Applied Physics, Part 2: Letters|
|Issue number||9 A/B|
|State||Published - 15 Sep 1997|
- Boron penetration
- Gate depletion
- Gate microstructure