Method for producing a semiconductor wafer
A method for producing a semiconductor wafer sliced from a single crystal includes rounding an edge using a grinding disk containing abrasives with an average grain size of 20.0-60.0 μm. A first simultaneous double-side material-removing process is performed wherein the semiconductor wafers are processed between two rotating ring-shaped working disks, each working disk having a working layer containing abrasives having an average grain size of 5.0-20.0 μm, wherein the semiconductor wafer is placed in a cutout in one of a plurality of carriers rotatable by a rolling apparatus such that the semiconductor wafer lies in a freely movable manner in the carrier and the wafer is movable on a cycloidal trajectory. A second simultaneous double-side material-removing process is performed including processing the semiconductor wafers between two rotating ring-shaped working disks, each working disk having a working layer containing abrasives having an average grain size of 0.5-15.0 μm.
1. A method for producing a semiconductor wafer sliced from a single crystal and having an edge and two sides, the method comprising:
(a) rounding the edge using a grinding disk containing abrasives with an average grain size of 20.0-60.0 μm;
(b) performing a coarse PPG process for simultaneous double-side material removal wherein the semiconductor wafers are whole-area processed between two rotating ring-shaped working disks, each rotating ring-shaped working disk having a working layer containing abrasives having an average grain size of 5.0-20.0 μm and a Mohs hardness of ≧6, wherein the semiconductor wafer is placed in a cutout in one of a plurality of carriers rotatable by a rolling apparatus such that the semiconductor wafer lies in a freely movable manner in the carrier and the semiconductor wafer is movable on a cycloidal trajectory;
(c) performing a fine PPG process for simultaneous double-side material removal that includes whole area processing of the semiconductor wafers between two rotating ring-shaped working disks, each rotating ring-shaped working disk having a working layer containing abrasives having an average grain size of 0.5-15.0 μm and less than the average grain size used in step (b);
(d) further rounding the edge of the semiconductor wafer using a grinding disk containing abrasives having an average grain size of 1.0 -20.0 μm, wherein the average grain size used is less than the average grain size used in the rounding in step (a);
(e) treating the two sides with an etching medium together with a further material removal of not more than 1 μm per side;
(f) polishing at least one of the two sides using a polishing pad containing abrasives with an average grain size of 0.1-1.0 μm;
(g) polishing the edge of the semiconductor wafer; and
(h) chemical mechanical polishing (CMP) of at least a front side of the two sides.
2. The method as recited in claim 1 , wherein the polishing of the at least one of the two sides of step (f) includes polishing the front side using a polishing pad with fixedly bonded abrasives, and wherein the chemical mechanical polishing includes chemical mechanical polishing a rear side during the polishing the front side.
3. The method as recited in claim 1 , wherein the polishing of the at least one of the two sides is performed during the chemical mechanical polishing of step (h) and includes polishing the front side using a polishing pad with fixedly bonded abrasives.
4. The method as recited in claim 1 , wherein the abrasives of the polishing pad used in step (f) include at least one particle selected from the group consisting of silicon carbide, boron nitride, diamond, cerium oxide, aluminum oxide, silicon oxide and zirconium oxide.
5. The method as recited in claim 1 , wherein the further material removal in step (e) is at least 0.1 nm and at most 1 μm.
6. The method as recited in claim 1 , wherein the polishing the edge of step (g) includes:
centrally rotating the semiconductor wafer;
continuously supplying a polishing agent solution containing no solids; and
pressing the edge with a specific force against a centrally rotating polishing drum having a polishing pad, the polishing pad containing fixedly bonded abrasive particles selected from the group consisting of silicon carbide, boron nitride, diamond and oxides of the elements cerium, aluminum, silicon and zirconium.
7. The method as recited in claim 1 , wherein the average grain size of the abrasives of the grinding disk used in step (a) is one of 25-30 μm and 30-40 μm.
8. The method as recited in claim 1 , wherein the performing a first simultaneous double-side material-removing process of step (b) includes using two working disks having an average grain size of 5-10 μm,
9. The method as recited in claim 1 , wherein the performing a second simultaneous double-side material-removing process of step (c) includes using two working disks having an average grain size of 0.5-4 μm.
10. The method as recited in claim 1 , wherein the average grain size of the abrasives of the grinding disk used in step (a) is one of 0.5-10 μm.