Nucleation-free gap fill ALD process
Processing methods comprise forming a gap fill layer comprising tungsten or molybdenum by exposing a substrate surface having at least one feature thereon sequentially to a metal precursor and a reducing agent comprising hydrogen to form the gap fill layer in the feature, wherein there is not a nucleation layer between the substrate surface and the gap fill layer.
1. A processing method comprising:
placing a substrate having a substrate surface into a processing chamber comprising a plurality of sections, each section separated from adjacent sections by a gas curtain, the substrate surface having at least one feature with a top, bottom and sides and an aspect ratio of greater than or equal to 10:1;
exposing at least a portion of the substrate surface to a first process condition in a first section of the processing chamber, the first process condition comprising a precursor of titanium, aluminum, silicon, or combinations thereof;
laterally moving the substrate surface through a gas curtain to a second section of the processing chamber;
exposing the substrate surface to a second process condition in the second section of the processing chamber, the second process condition comprising a reactant to form a film with the precursor of titanium, aluminum, silicon or combinations thereof, the film comprising TiN, TiSiN, AlN, or TiAlN;
optionally repeating exposure to the first and second sections, including lateral movement of the substrate surface to form an underlying layer;
laterally moving the substrate surface through a gas curtain to a third section of the processing chamber;
exposing the substrate surface to a third process condition in the third section of the processing chamber, the third process condition comprising a tungsten precursor or molybdenum precursor;
laterally moving the substrate surface through a gas curtain to a fourth section of the processing chamber;
exposing the substrate surface to a fourth process condition in the fourth section of the processing chamber, the fourth process condition comprising hydrogen as a reductant to form a film with the tungsten precursor or molybdenum precursor; and
optionally repeating exposure to the third and fourth sections, including lateral movement of the substrate surface to fill the feature.
2. The processing method of claim 1 , wherein the reductant consists essentially of hydrogen.
3. The method of claim 1 , wherein the first process condition comprises the precursor of titanium, which is TiCl 4 , TiI 4 , or Ti[NMe 2 ] 4 and the second process condition comprises NH 3 to form the underlying layer that comprises TiN.
4. The method of claim 1 , wherein prior to exposing the substrate surface to the second process condition, the substrate is exposed to a chemical treatment process condition in a chemical treatment section of the processing chamber, the chemical treatment process condition comprising one or more of the following:
Si x H 2x+2 , wherein x>=1;
Si X H y F Z , wherein x>=2 and y+z=2x+2;
Si x H y Cl z , wherein x>=2 and y+z=2x+2;
B x H y , wherein x>=2 and y<=2x+2;
B x H y Cl z , wherein x>=2 and y+z<=2x+2;
B X H y F Z , wherein x>=2 and y+z<=2x+2; and
BxHyRz, wherein x>=2, y+z<=2x+2, and R comprises an alkyl group having 1 to 6 carbons.