Condensate precursors and contaminant purge apparatus and methods

An apparatus, comprising:

• a vacuum chamber configured to support a substrate and hold the substrate at a cryogenic temperature;
• a condensate precursor system coupled to the vacuum chamber, wherein the condensate precursor system includes:
• a storage crucible configured to store a bulk precursor condensate material in a storage reservoir, the bulk precursor condensate material including a condensate precursor and one or more volatile contaminants,
• a vacuum chamber outlet valve coupled to the storage reservoir and configured to release a vapor phase of the condensate precursor into the vacuum chamber to condense on the substrate that is held at the cryogenic temperature to form a deposition layer on the substrate,
• at least one vacuum pump,
• a vacuum valve coupled to the vacuum pump, and
• a feedthrough coupling the storage reservoir to the vacuum pump through the vacuum valve,
• wherein the vacuum pump is configured to draw a vacuum on the storage reservoir to reduce a vapor pressure build-up of the one or more volatile contaminants in the storage reservoir and thereby reduce a deposition of the one or more contaminants on the substrate during the condensing of the condensate precursor on the substrate.