Low temperature reflow method for filling high aspect ratio contacts
AssigneeMicron Technology, Inc.
InventorsShubneesh Batra, Gurtej Sandhu
Life of this patent
Estimating the term…
Abstract
Impurities are added to a conductor layer in a semiconductor process to prevent formation of void spaces and encourage complete filling of contacts. The impurities reduce the melting point and surface tension of a conductor layer, thereby improving filling characteristics during a reflow step. The impurities may be added at any time during the process, including during conductor deposition and/or reflow.
Claims19
A method of forming a contact, the method comprising the steps of:
- (a) providing a substrate having a contact hole formed therein, the contact hole exposing a portion of a conductive area of the substrate;
- (b) depositing conductive material comprising aluminum into the contact hole at a temperature that causes the conductive material to reflow, the conductive material having a surface tension and a melting point;
- and
- (c) depositing an impurity intermittently into the conductive material while the conductive material is being deposited, the impurity causing at least one of the surface tension and the melting point of the conductive material to lower.
A method of forming a contact, the method comprising the steps of:
- (a) providing a substrate having a contact hole formed therein, the contact hole exposing a portion of a conductive area of the substrate;
- (b) depositing conductive material comprising aluminum into the contact hole at a temperature within a range of 300 degrees Celsius to 500 degrees Celsius, the conductive material having a surface tension and a melting point;
- and
- (c) depositing a gaseous impurity comprising TiCl4 into the conductive material after about 70% of the conductive material has being deposited, the impurity causing at least one of the surface tension and the melting point of the conductive material to lower.
A method of filling a feature having a high aspect ratio, the method comprising the steps of:
- (a) depositing conductive material into the high aspect ratio feature at a temperature that causes the conductive material to reflow, the conductive material having a surface tension and a melting point;
- and
- (b) depositing an impurity intermittently into the conductive material while the conductive material is being deposited, the impurity causing at least one of the surface tension and the melting point of the conductive material to lower.
Dependencies are inferred from the claim text.