×

Process for fabricating a semiconductor device having contact hole open to impurity region coplanar with buried isolating region

  • US 5,972,774 A
  • Filed: 01/22/1997
  • Issued: 10/26/1999
  • Est. Priority Date: 02/21/1995
  • Status: Expired due to Fees
First Claim
Patent Images

1. A process for fabricating a semiconductor device, comprising the steps of:

  • selectively forming a groove in a semiconductor substrate so as to define an active area in said semiconductor substrate;

    forming a first insulating layer in said groove so as to partially fill said groove;

    forming a second insulating layer on said first insulating layer so that said first insulating layer and said second insulating layer form in combination a buried isolating region filling in said groove;

    selectively introducing a dopant impurity into said active area so as to form an impurity region having a portion held in contact with a side surface of said buried isolating region;

    forming an inter-level insulating layer of an insulating material different from that of said second insulating layer so that said buried isolating region and said impurity regions are covered with said inter-level insulating layer;

    selectively removing said inter-level insulating layer so as to form a contact hole to which said portion of said impurity region and a part of said buried isolating region are exposed, said second insulating layer serving as an etching stopper during the selective removal of said inter-level insulating layer andforming a contact structure in said contact hole and in contact with said buried isolating region by depositing a first refractory metal layer on the inner surface of said contact hole, depositing a second refractory metal layer on the first refractory metal layer, depositing a conductive metal layer on the second refractory metal layer, and uniformly etching the conductive metal layer so as to leave behind a plug of said conductive metal in said contact hole.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×