Method and apparatus for drying wafers

Apparatus for drying moisture from a wafer in a way to prevent stains on the sides of the wafer after the wafer has been washed on both sides, said apparatus comprising,

• wet wafer conveying means for conveying a wet wafer to a drying station,
• dry wafer conveying means for conveying the dry wafer away from the drying station,
• wafer holding means for holding the wafer by gripping the wafer on the edges of the wafer at the drying station,
• positioning means for lowering the wet wafer holder below the wet wafer conveying means and dry wafer conveying means,
• rotating means for rotating the holder and wafer to spin-dry the wafer while the wafer is below the wet wafer conveying means and dry wafer conveying means,
• and wherein said positioning means are effective to raise the dry wafer to the level of the dry wafer conveying means after the wafer has been spin-dryed by the rotating means and wherein the wet wafer conveying means and dry wafer conveying means are at different levels at the drying station to prevent any contact of the dry wafer with residual moisture at the wet wafer conveying means.

Apparatus for drying moisture from a wafer in a way to prevent stains on the sides of the wafer after the wafer has been washed on both sides, said apparatus comprising,

• wet wafer conveying means for conveying a wet wafer to a drying station,
• dry wafer conveying means for conveying the dry wafer away from the drying station,
• wafer holder means for holding the wafer by gripping the wafer on the edges of the wafer at the drying station,
• positioning means for lowering the wet wafer holder below the wet wafer conveying means and dry wafer conveying means,
• rotating means for rotating the holder and wafer to spin-dry the wafer while the wafer is below the wet wafer conveying means and dry wafer conveying means,
• and wherein said positioning means are effective to raise the dry wafer to the level of the dry wafer conveying means after the wafer has been spin dryed by the rotating means, and
• wherein the rotating means include a rotatable spindle, the wafer holder means include first and second slider members, each slider member has two wafer holder bumpers for gripping the edge of the wafer and the slider members are slidably mounted in the spindle to provide a nest which opens and closes on a wafer and including a cam slot in each slider member and a single cam roller engagable with the cam slots to control the lateral positions of the slider members with respect to one another.

A method for drying moisture from a wafer to prevent stains on the sides of the wafer after the wafer has been washed on both sides, said method comprising,

• conveying the wet wafer on a conveyor to a drying station,
• gripping the wafer on its edge by a wafer holder at the drying station,
• lowering the wet wafer and holder below the conveyor,
• rotating the holder and wafer to spin-dry the wafer while gripping the wafer only on the edge of the wafer,
• raising the dry wafer to the level of the conveyor,
• releasing the grip of the wafer holder on the edge of the wafer, and
• conveying the dry wafer on a conveyor away from the drying station.

A method of drying moisture from a wafer to prevent stains on the sides of the wafer after the wafer has been washed on both sides, said method comprising,

• conveying the wet wafer on a conveyor to a drying station,
• gripping the wafer on its edge by a wafer holder at the drying station,
• lowering the wet wafer and holder below the conveyor,
• rotating the holder and wafer to spin-dry the wafer,
• raising the dry wafer to the level of the conveyor,
• releasing the grip of the wafer holder on the edge of the wafer,
• conveying the dry wafer on a conveyor away from the drying station, and
• conveying the wet wafer into the drying station at one level and conveying the dry wafer away from the drying station at another level to prevent any contact between the dry wafer and residual moisture at the incoming level.

A wafer holder for gripping a wafer on its edge for centrifugal rinsing and spin drying of the wafer, said wafer holder comprising,

• a rotatable spindle having a spindle head and a slot extending transversely through the head,
• two slide members mounted for sliding movement in opposite directions in said slot,
• each of said slide members having a pair of laterally spaced apart uprights at the outer end of the slide member and a wafer gripping bumper on the upper end of each upright to form a nest which can be expanded and contracted by the opposite sliding movements of the two slide members,
• each slide member having a cam slot with the cam slots in the slide members crossed with respect to one another,
• a cam roller engaged with the cam slots, and
• an actuator rod disposed within the spindle and connected to the cam roller and movable longitudinally within the spindle to expand and to contract the nest formed by the wafer gripping bumpers.