Abstract: A method for rinsing wafers having residual chemical liquid adhering thereto with purified water is disclosed which is characterized by the steps of preparing a rinsing tank provided in the upper part thereof with an overflow discharge part for spent rinsing liquid and a head tank disposed above the rinsing tank, storing purified water for rinse in the head tank, setting in place in the rinsing tank a basket having a plurality of wafers stowed therein parallelly as suitably spaced in such a manner that the surfaces of the wafers may lie substantially vertically, feeding the purified water from the headtank to the rinsing tank by virtue of head, causing the purified water to flow upward from below the basket, and enabling the spent rinsing liquid to be discharged through the overflow discharge part in an amount equivalent to part or the whole of the purified water fed from the head tank.

Abstract: A method for rinsing wafers having residual chemical liquid adhering thereto with purified water is disclosed which is characterized by the steps of preparing a rinsing tank provided in the upper part thereof with an overflow discharge part for spent rinsing liquid and a head tank disposed above the rinsing tank, storing purified water for rinse in the head tank, setting in place in the rinsing tank a basket having a plurality of wafers stowed therein parallelly as suitably spaced in such a manner that the surfaces of the wafers may lie substantially vertically, feeding the purified water from the headtank to the rinsing tank by virtue of head, causing the purified water to flow upward from below the basket, and enabling the spent rinsing liquid to be discharged through the overflow discharge part in an amount equivalent to part or the whole of the purified water fed from the head tank.

Abstract: The single crystal silicon wafers which have undergone a treatment with a chemical liquid such as an acid or an alkali are stored without entailing contamination of their surfaces by causing the wafers to be immediately immersed, either directly or after being washed with water, in an aqueous hydrogen peroxide solution. The prevention of the contamination of surfaces of the wafers is attained effectively by setting the concentration of hydrogen peroxide in the aqueous hydrogen peroxide solution in the range of from 0.01 to 30% by weight and the temperature of the aqueous hydrogen peroxide solution at the time that the wafers are immersed in the solution in the range of from 10.degree. to 30.degree. C.

Abstract: A sound motion picture projection system which can be formed by a combination of a silent film projector and a sound recording and reproducing unit, wherein a silent film projector and a separate sound recording and reproducing unit are provided and minor modification is given to said silent film projector so that said silent film projector can be used as a projection unit only with said minor modification.