Heat transfer to ampoule trays

A vapor delivery vessel assembly for vaporizing and delivering vaporized source material, the vessel assembly comprising:

• a vessel body having an interior volume defined by a base and a sidewall, the sidewall defining an interior diameter of the vessel body and having an interior sidewall surface;
• a gas inlet and a gas outlet arranged in fluid communication with the interior volume of the vessel body, the gas inlet being adapted to supply a first gas to the interior volume of the vessel body;
• a first vented support tray disposed within the interior volume and adjacent the sidewall or interior wall of the vessel body, the support tray adapted to support on a first surface a vaporizable source material in the flow path extending between the gas inlet and the gas outlet;
• and
• a heat transfer assembly disposed on the first support tray and located between the vessel body sidewall and the first support tray, the heat transfer assembly supported at least partially by the first surface of the support tray within the interior volume of the vessel body wherein
• the heat transfer assembly includes a circumferential sidewall assembly that extends upwards from and is in contact with the support tray, the sidewall assembly adapted to expand radially out towards the sidewall of the vessel body to increase surface area physical contact between the support tray and the interior sidewall surface of the vessel body;
• or
• the heat transfer assembly includes a sidewall assembly that includes a section that is partially expandable radially out towards the sidewall of the vessel body to shift the support tray within the interior vessel volume to increase surface area physical contact between the support tray and the interior sidewall surface of the vessel body.