Methods for forming low moisture dielectric films

A method for forming a pre-metal dielectric (PMD) layer over a substrate, the method comprising:

• placing the substrate in a chemical vapor deposition (CVD) process chamber;
• forming a first oxide layer over the substrate in the CVD process chamber, the first oxide layer formed using a thermal CVD process at a temperature of about 450° C. or less and a sub-atmospheric pressure;
• forming a second oxide layer over the first oxide layer in the CVD process chamber, the second oxide layer formed using a plasma enhanced chemical vapor deposition (PECVD) process at a temperature of about 450° C. or less and a sub-atmospheric pressure, wherein the substrate remains in the CVD process chamber during formation of the first oxide layer and the second oxide layer;
• thereafter, removing the substrate from the CVD process chamber;
• and
• exposing the substrate to a degas process in a degas chamber, the degas process at a temperature of about 400° C. or more and a pressure of about 12 Torr or less.

A method for forming a pre-metal dielectric (PMD) layer and a metal layer over a substrate, the method comprising:

• placing the substrate in a chemical vapor deposition (CVD) process chamber;
• forming a first oxide layer over the substrate in the CVD process chamber, the first oxide layer formed using a thermal CVD process at a temperature of about 450° C. or less and a sub-atmospheric pressure;
• forming a second oxide layer over the first oxide layer in the CVD process chamber, the second oxide layer formed using a plasma enhanced chemical vapor deposition (PECVD) process at a temperature of about 450° C. or less and a sub-atmospheric pressure, wherein the substrate remains in the CVD process chamber during formation of the first oxide layer and the second oxide layer;
• thereafter, removing the substrate from the CVD process chamber;
• exposing the substrate to a degas process in a degas chamber, the degas process at a temperature of about 400° C. or more and a pressure of about 12 Torr or less;
• thereafter, forming a barrier layer over the second dielectric layer in a barrier deposition chamber;
• and
• thereafter, forming the metal layer over the barrier layer in a metal deposition chamber.