Process for stripping outer edge of BESOI wafers
AssigneeSiBond, L.L.C.
InventorsDavid I. Golland, Robert A. Craven, Ronald D. Bartram
Life of this patent
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Abstract
A process for stripping the outer edge of a bonded BESOI wafer. The bonded BESOI wafer comprises a handle wafer, an oxide layer on one surface of the handle wafer, a device layer bonded to the oxide layer, and a p.sup.+ etch-stop layer on the device layer having an exposed face. The process comprises masking the exposed face of the p.sup.+ etch-stop layer, and abrading the periphery of the BESOI wafer to remove edge margins of the p.sup.+ etch-stop layer and device layer.
Claims17
A process for stripping the outer edge of a bonded BESOI wafer comprising a handle wafer having a face, an oxide layer on the face of the handle wafer, a device layer bonded to the oxide layer, the device layer having an edge margin, and a p.sup.+ layer on the device layer, the p.sup.+ layer having an edge margin and an exposed face, the process comprising
- masking the exposed face of the p.sup.+ layer;
- removing the edge margins of the p.sup.+ layer and the device layer, and
- removing the p.sup.+ layer to expose the device layer.
A process for stripping the outer edge of a bonded BESOI wafer comprising a handle wafer having a face, an oxide layer on the face of the handle wafer, a device layer bonded to the oxide layer, the device layer having an edge margin, and a p.sup.+ layer on the device layer, the p.sup.+ layer containing about 1.times.10.sup.19 atoms/cm.sup.3 to about 5.times.10.sup.20 atoms/cm.sup.3 of boron and having an edge margin and an exposed face, the process comprising
- forming a mask on the exposed face of the p.sup.+ layer;
- removing the edge margins of the p.sup.+ layer and the device layer;
- stripping the mask from the exposed face of the p.sup.+ layer after the edge-margins of the p.sup.+ layer and the device layer have been removed;
- and
- removing the p.sup.+ layer after the mask has been stripped by exposing the p.sup.+ layer to an etchant.
A process for stripping the outer edge of a bonded BESOI wafer comprising a handle wafer having a face, an oxide layer on the face of the handle wafer, a device layer bonded to the oxide layer, the device layer having an edge margin, and a layer on the device layer which is preferentially etchable relative to the device layer, the preferentially-etchable layer having an edge margin and an exposed face, the process comprising
- masking the exposed face of the preferentially-etchable layer,
- removing a peripheral portion of the preferentially-etchable layer and the device layer, the removed portion consisting of the edge margin of the preferentially-etchable layer and the edge margin of the device layer, and
- after the peripheral portion of the preferentially-etchable layer and the device layer are removed, removing the remaining portion of the preferentially-etchable layer to expose the remaining portion of the device layer.
Dependencies are inferred from the claim text.