Apparatus and method for delivery of precursor vapor from low vapor pressure liquid sources to a CVD chamber

A method of delivering low vapor pressure liquid precursor vapor to a CVD processing chamber, the method comprising:

• providing a source of liquid precursor at a CVD processing chamber having therein a substrate on a substrate support;
• providing a vaporizer in integral communication with the processing chamber, the vaporizer having a high flow-conductance path for atomized precursor to the processing chamber;
• flowing liquid precursor from the source thereof to an atomizing device while controlling the temperature of the precursor when in the liquid state at a temperature below a temperature at which the liquid precursor is unstable;
• atomizing liquid precursor at a controlled flow rate from the source and feeding the atomized precursor to an input of the vaporizer high-flow conductance path;
• expanding the vaporized precursor to the CVD processing chamber;
• and
• controlling the temperature of the expanding atomized precursor in the vaporizer high flow-conductance path by adding heat to the precursor as it expands and is diffused into the reactor so that the precursor neither condenses, deposits nor reacts upon entering the chamber.