Structures for preventing gate oxide degradation

Details Structures for preventing gate oxide degradation Structures for preventing gate oxide degradation

1996-05-10

1998-06-16

Crane, Sara W.

Active solid-state devices (e.g., transistors, solid-state diode

Field effect device

Having insulated electrode

217750, 217751, 217754, 217755, 217756, 217757, 217758, 217763, 217413, H01L 2976, H01L 2348

Patent

active

057675589

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: 5214305 (1993-05-01), Huang et al.
patent: 5256894 (1993-10-01), Shino
patent: 5364803 (1994-11-01), Lur et al.
patent: 5371396 (1994-12-01), Vinal et al.

Affiliated with

Also associated with

Rating

Structures for preventing gate oxide degradation does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Structures for preventing gate oxide degradation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structures for preventing gate oxide degradation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1729161