Quartz member such as a
quartz tube for
semiconductor manufacturing equipment capable of
heat treating a substrate to be treated without causing
contamination, a manufacturing method of such
quartz member,
thermal treatment equipment furnished with such
quartz member, and an
analysis method of
metal in quartz member are provided. A quartz specimen is immersed in
hydrofluoric acid to
expose a layer to be analyzed located at a prescribed depth. On an exposed surface, a
decomposition liquid such as
hydrofluoric acid or
nitric acid is dripped to decompose only an extremely
thin layer to be analyzed, followed by recovering of the
decomposition liquid. The
decomposition liquid is quantitatively analyzed by use of
atomic absorption spectroscopy (AAS) or the like to measure an amount of
metal contained in the decomposition liquid. From a difference of thicknesses before and after the decomposition and an area of dripped decomposition liquid, a volume of a decomposed layer to be analyzed is obtained. From this and the amount of
metal contained in the decomposition liquid, a concentration of metal contained in the layer to be analyzed, in addition a
diffusion coefficient of a layer to be analyzed is calculated. With thus obtained
diffusion coefficient as an index, quartz material in which metal diffuses with difficulty is sorted out. With thus sorted quartz material, a quartz member used for
semiconductor manufacturing equipment such as a quartz tube is manufactured.