Methods for preventing gate oxide degradation

Details Methods for preventing gate oxide degradation Methods for preventing gate oxide degradation

1997-09-12

2000-07-25

Trinh, Michael

Semiconductor device manufacturing: process

Making field effect device having pair of active regions...

Having insulated gate

438592, 438647, 438655, H01L 21336, H01L 213205

Patent

active

060935898

ABSTRACT:
The degradation of integrity of the gate oxide in a CMOS transistor due to the formation of a tungsten silicide strapping layer on the polycrystalline silicon gate as a result of the migration of fluorine atoms from the tungsten hexafluoride used to form the tungsten silicide is reduced by increasing the dopant concentration of the polycrystalline silicon layer thereby to form dopant atoms in the grain boundaries of the polycrystalline silicon to block the migration of fluorine through the polycrystalline silicon to the underlying gate oxide. By preventing fluorine from reaching the gate oxide in this manner, the degradation of the gate oxide due to the replacement of oxygen by fluorine is decreased. The method maintains the gate-oxide integrity (such as charge-to-breakdown characteristics), and the method also makes more predictable the performance of the resulting transistors by reducing the thickening of the oxide due to the migration of oxygen replaced by fluorine into the underlying silicon substrate thereby to form additional silicon oxide. The polysilicon thus preserves the gate oxide integrity. In addition, the heavily-doped polysilicon will also sufficiently dope the contacted polysilicon and thus reduce the contact resistance of the polycrystalline silicon and silicon.

REFERENCES:
patent: 4816425 (1989-03-01), McPherson
patent: 4886764 (1989-12-01), Miller et al.
patent: 4897368 (1990-01-01), Kobushi et al.
patent: 5164333 (1992-11-01), Schwalke et al.
patent: 5214305 (1993-05-01), Huang et al.
patent: 5256894 (1993-10-01), Shino
patent: 5274261 (1993-12-01), Chen
patent: 5364803 (1994-11-01), Lur et al.
patent: 5371396 (1994-12-01), Vinal et al.
patent: 5425392 (1995-06-01), Thakur et al.
patent: 5710454 (1998-01-01), Wu

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