US 6,982,228 B2
Methods of etching a contact opening over a node location on a semiconductor substrate
Mark E. Jost, Boise, Id. (US); and Chris W. Hill, Boise, Id. (US)
Assigned to Micron Technology, Inc., Boise, Id. (US)
Filed on Oct. 22, 2002, as Appl. No. 10/278,530.
Application 10/278530 is a division of application No. 09/797898, filed on Mar. 01, 2001, granted, now 6,596,641.
Prior Publication US 2003/0045111 A1, Mar. 06, 2003
Int. Cl. H01L 21/302 (2006.01)
U.S. Cl. 438—738 32 Claims
OG exemplary drawing
 
1. A method of etching a contact opening over a node location on a semiconductor substrate, comprising:
forming a dielectric first layer over a node location;
forming an oxide second layer having plural dopants therein over the dielectric first layer, the oxide second layer having an innermost portion and an outer portion, the outer portion having a higher concentration of one of the dopants than any concentration of the one dopant in the innermost portion;
using a single dry etching chemistry, etching a contact opening into the outer and innermost portions of the oxide second layer to proximate the dielectric first layer over the node location; and
etching into the dielectric first layer through the contact opening to proximate the node location.