Non-polished glass wafer, thinning system and method for using the non-polished glass wafer to thin a semiconductor wafer
A non-polished glass wafer, a thinning system, and a method for using the non-polished glass wafer to thin a semiconductor wafer are described herein. In one embodiment, the glass wafer has a body (e.g., circular body) including a non-polished first surface and a non-polished second surface substantially parallel to each other. In addition, the circular body has a wafer quality index which is equal to a total thickness variation in micrometers plus one-tenth of a warp in micrometers that is less than 6.0.
1. A method for manufacturing non-polished glass wafers, the method comprising the steps of:
melting batch materials and forming molten glass;
providing a forming device for receiving the molten glass and forming a glass sheet;
providing an apparatus comprising an enclosure disposed about the forming device, the enclosure comprising an opening below the forming body to allow a flow of molten glass descending from the forming device to pass from the enclosure, the apparatus further comprising thermal shields positioned below the forming device and spaced apart to form the opening, where the thermal shields are configured for minimizing radiative heat loss from the forming device, each thermal shield being movable relative to the flow of the molten glass, the apparatus further comprises cooling members positioned adjacent to the thermal shields, wherein the step of providing the enclosure further comprises steps of,
controlling a pressure within the enclosure;
controlling the cooling members; and
minimizing the opening between the thermal shields to control heat transfer uniformity with respect to the glass sheet;
drawing the glass sheet;
separating the glass sheet into distinct glass sheets; and
cutting at least one of the distinct glass sheets into a plurality of non-polished glass wafers,
wherein each non-polished lass wafer comprises:
a body including a non-polished first surface and a non-polished second surface which are substantially parallel to each other;
the body has a wafer quality index which is less than about 6.0, wherein the wafer quality index is equal to a total thickness variation in micrometers plus one-tenth of a warp in micrometers, wherein the total thickness variation is a difference between a highest thickness elevation and a lowest thickness elevation across the body between the non-polished first surface and the non-polished second surface, and the warp is a sum of absolute values of a maximum distance between a highest point and a least squares focal plane applied to a shape of the body and a maximum distance between a lowest point and the least squares focal plane applied to the shape of the body, where the highest point and the lowest point are both with respect to same surface of the body.
2. The method of claim 1 , wherein the non-polished first surface has a surface roughness less than about 5 Å RMS.