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AssigneeMEMC Electronic Materials, Inc.
InventorsRobert A. Falster, Joseph C. Holzer, Marco Cornara, Daniela Gambaro, Massimiliano Olmo, Steve A. Markgraf, Paolo Mutti, Seamus A. McQuaid, Bayard K. Johnson
Estimating the term…
A single crystal silicon wafer which, during the heat treatment cycles of essentially any electronic device manufacturing process, will form an ideal, non-uniform depth distribution of oxygen precipitates. The wafer is characterized in that is has a non-uniform distribution of crystal lattice vacancies, the concentration of vacancies in the bulk layer being greater than the concentration of vacancies in the surface layer and the vacancies having a concentration profile in which the peak density of the vacancies is at or near a central plane with the concentration generally decreasing from the position of peak density in the direction of a front surface of the wafer. In one embodiment, the wafer is further characterized in that it has a first axially symmetric region in which vacancies are the predominant intrinsic point defect and which is substantially free of agglomerated intrinsic point defects, wherein the first axially symmetric region comprises a central axis or has a width of at least about 15 mm. In another embodiment, the wafer is further characterized in that it has an axially symmetric region which is substantially free of agglomerated intrinsic point defects, the axially symmetric region extending radially inwardly from a circumferential edge of the wafer and having a width, as measured from the circumferential edge radially toward a center axis, which is at least about 40% the length of a radius of the wafer.
A single crystal silicon wafer having two major, generally parallel surfaces, one of which is the front surface of the wafer and the other of which is the back surface of the wafer, a central plane between the front and back surfaces, a circumferential edge joining the front and back surfaces, a central axis generally perpendicular to the front and back surfaces, a radius extending from the central axis to the circumferential edge, a surface layer which comprises the region of the wafer between the front surface and a distance, D1, of at least about 10 micrometers measured from the front surface and toward the central plane, and a bulk layer which comprises a second region of the wafer between the central plane and the first region, the wafer being characterized in that
A single crystal silicon wafer having two major, generally parallel surfaces, one of which is the front surface of the wafer and the other of which is the back surface of the wafer, a central plane between the front and back surfaces, a circumferential edge joining the front and back surfaces, a central axis generally perpendicular to the front and back surfaces, a radius extending from the central axis to the circumferential edge, and a denuded zone which comprises the region of the wafer from the front surface to a distance, D1, of at least about 10 micrometers measured in the direction of the central plane and which contains interstitial oxygen, the wafer being characterized in that
A single crystal silicon wafer comprising two major, generally parallel surfaces, one of which is the front surface of the wafer and the other of which is the back surface of the wafer, a central plane between the front and back surfaces, a circumferential edge joining the front and back surfaces, a central axis generally perpendicular to the front and back surfaces, a radius extending from the central axis to the circumferential edge, a front surface layer consisting of the region of the wafer within a distance, D2, of no more than about 15 micrometers of the front surface and a bulk layer comprising the region of the wafer between the central plane and the front surface layer, the wafer being characterized in that
Dependencies are inferred from the claim text.