Method of forming and removing polysilicon lightly doped drain s

Details Method of forming and removing polysilicon lightly doped drain s Method of forming and removing polysilicon lightly doped drain s

1989-05-23

1991-05-07

Chaudhuri, Olik

Fishing, trapping, and vermin destroying

437 41, 437 34, 437 56, 437 57, 437233, 156625, 156628, H01L 21265, H01L 214763

Patent

active

050136755

ABSTRACT:
A method of forming and removing spacers used to mask lightly doped drain (LDD) regions in the formation of a field effect transistor (FET) involves depositing a thin oxide layer over the active region of a substrate and a gate structure formed on the active region. A polysilicon film is provided over the oxide and then doped using a POCl.sub.3 dopant. The polysilicon layer is then etched to form spacers at the ends of the gate and the spacers are used to mask lightly doped drain regions in the substrate during the implantation of source and drain regions. After the implant to form the source and drain regions, the device is subjected to a rapid thermal annealing for approximately 20-60 seconds at approximately 900.degree. C. in an inert atmosphere to cure any damage to the oxide layer which occurs during the source/drain implant. Curing the oxide layer reduces the etch rate of the oxide layer for an etchant which is designed to selectively etch the polysilicon spacers faster than it etches the oxide layer. The POCl.sub.3 doping of the polysilicon layer increases the etch rate of the polysilicon, thus enhancing the selectivity of the etching of the polysilicon versus the oxide layer.

REFERENCES:
patent: 4383885 (1983-05-01), Maydan
patent: 4488351 (1984-12-01), Momase
patent: 4642878 (1987-02-01), Maeda
patent: 4728617 (1988-03-01), Woo et al.
patent: 4753898 (1988-06-01), Parrillo
patent: 4789426 (1988-12-01), Pipkin
patent: 4818714 (1989-04-01), Haskell
patent: 4855247 (1989-08-01), Ma et al.
patent: 4859620 (1989-08-01), Wei et al.
Wolf et al., Silicon Processing for the VLSI Era, vol. 1, Process Technology, Lattice Press, 1986.
Pfiester, "LDD MOSFET's Using Disposable Sidewall Spacer Technology,"IEEE Electron Device Letters, vol. 9, No. 4, Apr. 1988, pp. 189-192.

Affiliated with

Also associated with

Rating

Method of forming and removing polysilicon lightly doped drain s does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of forming and removing polysilicon lightly doped drain s, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of forming and removing polysilicon lightly doped drain s will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-939300