Method for making self-aligned bit line contacts on a DRAM circu

Details Method for making self-aligned bit line contacts on a DRAM circu Method for making self-aligned bit line contacts on a DRAM circu

1996-06-21

1997-09-23

Tsai, Jey

Fishing, trapping, and vermin destroying

437 60, 437919, H01L 2170

Patent

active

056704046

ABSTRACT:
An improved method for fabricating self-aligned contacts in a planar insulating layer to the source/drain contact areas on field effect transistors (FETs), formed in part from a first polycide layer, is achieved using an undoped polysilicon layer as an etch-stop layer. The planar insulating layer provides a good surface for patterning a second polycide layer without intralevel shorts that would otherwise occur over a rough topography. This is of particular use for forming the array of bit lines over the array of word lines for DRAM circuits. The method involves providing a patterned undoped polysilicon layer on the gate electrodes. A planarized insulating layer, such as reflowed borophosphosilicate glass (BPSG) is then deposited and reflowed to fill the high aspect ratio recesses between the closely spaced word lines. The bit line contact openings are anisotropically plasma etched in the BPSG to the FET source/drain contact areas, while using the undoped polysilicon layer over the gate electrodes as an etch-stop layer to form self-aligned contacts without etching into the gate electrodes.

REFERENCES:
patent: 4971924 (1990-11-01), Tigelaar et al.
patent: 5422315 (1995-06-01), Kobayashi
patent: 5476805 (1995-12-01), Woo et al.
patent: 5491103 (1996-02-01), Ahn et al.

Affiliated with

Also associated with

Rating

Method for making self-aligned bit line contacts on a DRAM circu 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 for making self-aligned bit line contacts on a DRAM circu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for making self-aligned bit line contacts on a DRAM circu will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1938463