Method for depositing nanolaminate thin films on sensitive surfaces
The present method provides tools for growing conformal metal nitride, metal carbide and metal thin films, and nanolaminate structures incorporating these films, from aggressive chemicals. The amount of corrosive chemical compounds, such as hydrogen halides, is reduced during the deposition of transition metal, transition metal carbide and transition metal nitride thin films on various surfaces, such as metals and oxides. Getter compounds protect surfaces sensitive to hydrogen halides and ammonium halides, such as aluminum, copper, silicon oxide and the layers being deposited, against corrosion. Nanolaminate structures ( 20 ) incorporating metal nitrides, such as titanium nitride ( 30 ) and tungsten nitride ( 40 ), and metal carbides, and methods for forming the same, are also disclosed.
1. An atomic layer deposition (ALD) process for growing a carbon-containing metallic film on a substrate in a reaction space comprising the sequential steps of:
a) feeding a vapor-phase pulse of a metal source chemical into the reaction space with an inert carrier gas;
b) purging the reaction space with an inert gas;
c) feeding a vapor-phase pulse of a gettering compound into the reaction space, wherein the gettering compound comprises carbon and leaves carbon in the film and wherein the gettering compound is selected from the group consisting of alkyl aluminum, alkyl zinc, organo-lead, organo-iron, gallium and indium compounds that have at least one metal-carbon bond;
d) purging the reaction space with an inert gas; and
e) repeating steps a) through d) until the carbon-containing metal film of a desired thickness is formed.
2. The process of claim 1 , wherein the gettering compound is trimethylaluminum.
3. An atomic layer deposition (ALD) process for growing a metal nitride film on a substrate in a reaction space comprising the sequential steps of:
a) feeding a vapor-phase pulse of a metal source chemical into the reaction space with an inert carrier gas;
b) purging the reaction space with an inert gas;
c) feeding a vapor-phase pulse of a carbon compound into the reaction space wherein the carbon compound is selected from the group consisting of carbon compounds where there exists double or triple bonded carbon;
d) purging the reaction space with an inert gas;
e) feeding a vapor-phase pulse of a nitrogen source chemical into the reaction space;
f) purging the reaction space with an inert gas; and
g) repeating steps a) through f) until a metal nitride film of a desired thickness is formed.
4. The process of claim 3 , wherein the carbon compound is C 2 H 2 or C 2 H 4 .