Wafer processing apparatus providing cleaning and etching units with separate shrouds and enclosing separate spinner tables
A wafer processing apparatus includes a chuck table for holding the wafer thereon, a grinding unit having a rotatable grinding wheel with an annular array of grindstones mounted thereon for grinding a surface of the wafer, a cleaning unit for cleaning the wafer that has been ground, and an etching unit for removing a strain from the ground surface of the wafer. The grinding wheel is smaller in diameter than the wafer, enabling the grindstones mounted on the grinding wheel to thin down an inner region of the wafer that includes the ground surface, leaving an outer circumferential ring-shaped stiff portion on the wafer. The etching unit supplies an etching liquid to the inner region of the wafer inward of the outer circumferential ring-shaped stiff portion of the wafer for thereby removing a strain from the ground surface of the wafer.
1 . A wafer processing apparatus for processing a wafer, comprising:
a chuck table for holding the wafer thereon;
a grinding unit having a rotatable grinding wheel with an annular array of grindstones mounted thereon for grinding a surface of the wafer held on the chuck table;
a cleaning unit for cleaning the wafer that has been ground by the grinding unit; and
an etching unit for removing a strain from the ground surface of the wafer, wherein:
the grinding wheel of the grinding unit is smaller in diameter than the wafer, enabling the grindstones mounted on the grinding wheel to thin down an inner region of the wafer that includes the ground surface, leaving an outer circumferential ring-shaped stiff portion on the wafer,
the etching unit supplies an etching liquid to the inner region of the wafer inward of the outer circumferential ring-shaped stiff portion of the wafer to thereby remove a strain from the ground surface of the wafer,
the grinding unit, the cleaning unit, and the etching unit are housed in a single apparatus and are configured such that the wafer is transferred directly from the grinding unit to the cleaning unit and then to the etching unit without being stored in a cassette or transferred to a separate apparatus, and
both the cleaning unit and the etching unit include separate shrouds which are configured to enclose separate spinner tables during respective liquid processing.
2 . The wafer processing apparatus according to claim 1 , wherein
the cleaning unit includes a rotatable spinner table for holding the wafer under suction thereon and a cleaning water supply nozzle for supplying cleaning water to the ground surface of the wafer held on the spinner table, and
the etching unit includes a rotatable spinner table for holding the wafer under suction thereon and an etching liquid supply nozzle for supplying the etching liquid to the ground surface of the wafer held on the spinner table.
3 . The wafer processing apparatus according to claim 1 , wherein the cleaning unit is positioned between the grinding unit and the etching unit within a housing of the single apparatus.
4 . The wafer processing apparatus according to claim 1 , wherein the wafer is transferred from the grinding unit to the cleaning unit and from the cleaning unit to the etching unit by first and second delivery mechanisms, respectively, which operate entirely within a housing of the single apparatus.
5 . The wafer processing apparatus according to claim 1 , wherein the etching unit supplies the etching liquid while the wafer is rotated on a spinner table.
6 . The wafer processing apparatus according to claim 5 , wherein the etching liquid is supplied to the wafer while the outer circumferential ring-shaped stiff portion remains unetched.
7 . The wafer processing apparatus according to claim 1 , wherein the cleaning unit cleans the wafer after grinding and before etching to remove grinding swarf from the ground surface.
8 . The wafer processing apparatus according to claim 1 , wherein each of the shrouds define a sealed processing space around the respective spinner tables during liquid supply and centrifugal removal of liquid.
9 . The wafer processing apparatus according to claim 1 , wherein the wafer is transferred between the grinding unit, the cleaning unit, and the etching unit while remaining within an apparatus housing of the single apparatus.