Removal of metal contaminant deposited on quartz member of vertical heat processing apparatus

A system for cleaning a quartz member while removing aluminum contained as a metal contaminant in a surface of the quartz member of a vertical heat processing apparatus for a semiconductor process, the vertical heat processing apparatus including a reaction tube configured to accommodate a plurality of target substrates, a wafer boat configured to stack the target substrates at intervals inside the reaction tube, and a heat-insulating cylinder configured to place the wafer boat thereon inside the reaction tube, the quartz member being selected from the group consisting of the reaction tube, the wafer boat, and the heat-insulating cylinder, the system comprising:

• a diluted hydrofluoric acid cleaning section configured to clean the quartz member by use of a diluted hydrofluoric acid liquid by keeping the quartz member immersed in a bath consisting of the diluted hydrofluoric acid liquid;
• a hydrochloric acid cleaning section configured to clean the quartz member by use of a hydrochloric acid liquid set at an HCl concentration of 1 to 30 wt % by keeping the quartz member immersed in a bath consisting of the hydrochloric acid liquid;
• a deionized water cleaning section configured to clean the quartz member by use of a deionized water liquid by keeping the quartz member immersed in a bath consisting of the deionized water liquid;
• and
• a control section configured to control an operation of the system and including a storage medium storing a process recipe, which, when executed, causes the control section to control the system to conduct a sequence of cleaning the quartz member separated from the vertical heat processing apparatus, the sequence consisting of:
• performing a diluted hydrofluoric acid cleaning process of cleaning the quartz member by use of a diluted hydrofluoric acid liquid by keeping the quartz member immersed for a predetermined time in a bath consisting of the diluted hydrofluoric acid liquid in the diluted hydrofluoric acid cleaning section,
• then, performing a first deionized water cleaning process of cleaning the quartz member by use a of first deionized water liquid by keeping the quartz member immersed for a predetermined time in a bath consisting of the first deionized water liquid in the deionized water cleaning section,
• then, making a first judgment of whether the first deionized water cleaning process should be finished, followed by further performing the first deionized water cleaning process until the first judgment results in a determination that the first deionized water cleaning process should be finished;
• then, performing a hydrochloric acid cleaning process of cleaning the quartz member by use of a hydrochloric acid liquid set at an HCl concentration of 1 to 30 wt % by keeping the quartz member immersed for a predetermined time in a bath consisting of the hydrochloric acid liquid in the hydrochloric acid cleaning section, and
• then, performing a second deionized water cleaning process of cleaning the quartz member by use of second deionized water liquid by keeping the quartz member immersed for a predetermined time in a bath consisting of the second deionized water liquid in the purified deionized water cleaning section;
• and
• then, making a second judgment of whether the second deionized water cleaning process should be finished, followed by further performing the second deionized water cleaning process or further performing the hydrochloric acid cleaning process and the second deionized water cleaning process until the second judgment results in a determination that the second deionized water cleaning process should be finished,
• wherein the sequence ends by performing the second deionized water cleaning process after the hydrochloric acid cleaning process.