Patent Number: 6,309,967

Title: Method of forming a contact

Abstract: A high aspect ratio submicron VLSI contact and corresponding method ofmanufacture is disclosed. The contact is formed through an insulativelayer, such as silicon dioxide, to an underlying active region on asubstrate of silicon wafer. The contact comprises a layer of titaniumgermanosilicide at the bottom of the contact opening, and a layer oftitanium germanide at the sides of the contact opening, with an overlyinglayer of titanium nitride. The contact is metallized, preferably usingtungsten or aluminum. The disclosed method of manufacturing the contactcomprises first etching the contact opening, then exposing the bottom ofthe contact opening to germane gas to clean native silicon dioxide fromthe bottom of the contact opening. A 50 Angstrom layer of germanium isthen deposited over the contact opening. A layer of titanium is thendeposited over the germanium layer in the contact opening. The depositionof titanium is preferably accomplished using a collimator having an aspectratio lower than about 2.5:1. After annealing in a nitrogen atmosphere,the contact is metallized with tungsten or aluminum. The anneal step canbe conducted at a temperature of around C. Less titanium maybe used than with conventional processes, allowing a higher aspect ratioof the contact opening as well as the use of the collimator having a lowerthan conventional aspect ratio.

Inventors: Honeycutt; Jeffrey (Boise, ID), Sharan; Sujit (Boise, ID)


International Classification:

Expiration Date: 10/32013