Abstract: There is disclosed a silicon focus ring consisting of silicon single crystal used as a silicon focus ring in a plasma apparatus, wherein concentration of interstitial oxygen contained in the silicon focus ring is not less than 5×1017 atoms/cm3 and not more than 1.5×1018 atoms/cm3, and a producing method for a silicon focus ring used for a plasma apparatus, wherein a single crystal silicon wherein concentration of interstitial oxygen contained in the silicon focus ring is not less than 5×1017 atoms/cm3 and not more than 1.5×1018 atoms/cm3 is grown by a Czochralski method, the single crystal silicon is processed in a circle, and a silicon focus ring is produced. There can be provided a silicon focus ring, which can prevent disadvantage due to impurities such as heavy metal.

Abstract: There is disclosed a silicon electrode plate including silicon single crystal used as an upper electrode in a plasma etching apparatus wherein concentration of interstitial oxygen contained in the silicon electrode plate is not less than 5×1017 atoms/cm3 and not more than 1.5×1018 atoms/cm3, and the silicon electrode plate wherein nitrogen concentration in the silicon electrode plate is not less than 5×1013 atoms/cm3 and not more than 5×1015 atoms/cm3. There can be provided a silicon electrode plate consisting of silicon single crystal used as an upper electrode in a plasma etching apparatus wherein problems due to adhesion of impurities such as heavy metal or the like can be prevented.

Abstract: A chip conveyer which comprises a cylindrical trough having a discharge gate at one end thereof and a plurality of feed openings to receive metal chip and a plurality of endless chains laid within the trough thereby metal chip is transmitted from feed openings to the discharge gate and clinging chip to the endless chains is split by vibration generated by means of a cam means.