摘要:
A process for producing semiconductor wafers by double-sided polishing between two rotating, upper and lower polishing plates, which are covered with polishing cloth, while an alkaline polishing abrasive with colloidal solid fractions is being supplied, the semiconductor wafers being guided by carriers which have circumferential gear teeth and are set in rotation by complementary outer gear teeth and inner gear teeth of the polishing machine, which is distinguished by the following process steps: (a) at least one of the two sets of gear teeth of the polishing machine is at least from time to time sprayed with a liquid which substantially comprises water, (b) the alkaline polishing abrasive is fed continuously to the semiconductor wafers in a closed supply device. There is also a device which is suitable for carrying out the process.
摘要:
A process is for material-removing machining, on both sides simultaneously, of semiconductor wafers having a front surface and a back surface, the semiconductor wafers resting in carriers which are set in rotation by means of an annular outer drive ring and an annular inner drive ring and being moved between two oppositely rotating working disks in a manner which can be described by means of in each case one path curve relative to the upper working disk and one path curve relative to the lower working disk, wherein the two path curves after six loops around the center have the appearance of still being open, and at each point have a radius of curvature which is at least as great as the radius of the inner drive ring.
摘要:
A process for the double-side polishing of semiconductor wafers between two polishing plates which rotate in opposite directions and are covered with polishing cloth, so that at least 2 &mgr;m of semiconductor material is removed. The semiconductor wafers lay in plastic-lined cutouts in a set of a plurality of planar carriers which are made from steel and the mean thickness of which is 2 to 20 &mgr;m smaller than the mean thickness of the fully polished semiconductor wafers. The set comprises only those carriers whose difference in thickness is at most 5 &mgr;m, and each carrier belonging to the set has at least one unambiguous identification feature which assigns it to the set. An item of information contained in the identification feature is used in order for the plastic linings to be exchanged at fixed intervals and to ensure that the semiconductor wafers remain in the same order after the polishing as before the polishing. There is also a carrier which is suitable for carrying out the process.
摘要:
A semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface. In the semiconductor wafer, the epitaxial layer has a maximum local flatness value SFQRmax of less than or equal to 0.13 μm and a maximum density of 0.14 scattered light centers per cm2. The front surface of the semiconductor wafer, prior to the deposition of the epitaxial layer, has a surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 μm×1 μm reference area. Furthermore, there is a process for producing the semiconductor wafer. The process includes the following process steps: (a) as a single polishing step, simultaneous polishing of the front surface and of the back surface of the semiconductor wafer between rotating polishing plates while an alkaline polishing slurry is being supplied, the semiconductor wafer lying in a cutout of a carrier whose thickness is dimensioned to be 2 to 20 μm less than the thickness of the semiconductor wafer after the latter has been polished; (b) simultaneous treatment of the front surface and of the back surface of the semiconductor wafer between rotating polishing plates while a liquid containing at least one polyhydric alcohol having 2 to 6 carbon atoms is being supplied; (c) cleaning and drying of the semiconductor wafer; and (d) deposition of the epitaxial layer on the front surface of the semiconductor wafer produced in accordance with steps (a) to (c).
摘要:
A semiconductor wafer has a front surface and a back surface and flatness values based on partial areas of a surface grid on the front surface of the semiconductor wafer, which has a maximum local flatness value SFQRmax of less than or equal to 0.13 &mgr;m and individual SFQR values which in a peripheral area of the semiconductor wafer do not differ significantly from those in a central area of the semiconductor wafer. There is also a process for producing this semiconductor wafer, wherein the starting thickness of the semiconductor wafer is 20 to 200 &mgr;m greater than the thickness of the carrier and the semiconductor wafer is polished until the end thickness of the semiconductor wafer is 2 to 20 &mgr;m greater than the thickness of the carrier.
摘要:
A semiconductor wafer has a front surface and a back surface and flatness values based on partial areas of a surface grid on the front surface of the semiconductor wafer, which has a maximum local flatness value SFQRmax of less than or equal to 0.13 &mgr;m and individual SFQR values which in a peripheral area of the semiconductor wafer do not differ significantly from those in a central area of the semiconductor wafer. There is also a process for producing this semiconductor wafer, wherein the starting thickness of the semiconductor wafer is 20 to 200 &mgr;m greater than the thickness of the carrier and the semiconductor wafer is polished until the end thickness of the semiconductor wafer is 2 to 20 &mgr;m greater than the thickness of the carrier.
摘要:
A semiconductor wafer is guided in a cutout in a carrier while a thickness of the semiconductor wafer is reduced to a target thickness by material removal from the front and back surfaces simultaneously. The semiconductor wafer is machined until it is thinner than a carrier body and thicker than an inlay used to line the cutout in the carrier to protect the semiconductor wafer. The carrier is distinguished by the fact that the carrier body and the inlay have different thicknesses throughout the entire duration of the machining of the semiconductor wafer, the carrier body being thicker than the inlay, by from 20 to 70 μm. Themethod provides semiconductor wafers polished on both sides, having a front surface, a back surface and an edge, and a local flatness of the front surface, SFQRmax of less than 50 nm with an edge exclusion of R-2 mm and less than nm with an edge exclusion of R-1 mm, based on a site area of 26 by 8 mm.
摘要:
A semiconductor wafer is guided in a cutout in a carrier while a thickness of the semiconductor wafer is reduced to a target thickness by material removal from the front and back surfaces simultaneously. The semiconductor wafer is machined until it is thinner than a carrier body and thicker than an inlay used to line the cutout in the carrier to protect the semiconductor wafer. The carrier is distinguished by the fact that the carrier body and the inlay have different thicknesses throughout the entire duration of the machining of the semiconductor wafer, the carrier body being thicker than the inlay, by from 20 to 70 μm. The method provides semiconductor wafers polished on both sides, having a front surface, a back surface and an edge, and a local flatness of the front surface, SFQRmax of less than 50 nm with an edge exclusion of R-2 mm and less than 115 nm with an edge exclusion of R-1 mm, based on a site area of 26 by 8 mm.
摘要:
A method for producing a semiconductor wafer. The method includes placing the semiconductor wafer in a cutout in a carrier. Both sides of the semiconductor wafer are polished between an upper and a lower polishing plate with a polishing agent until the thickness of the center of the semiconductor wafer is less than the thickness of the carrier and from 10 μm to 30 μm of semiconductor wafer material is removed. The polishing agent contains 0.1 to 0.4% by weight of SiO2 and 0.1 to 0.9% by weight of an alkaline component.
摘要:
The invention relates to a carrier for holding semiconductor wafers during a double-side polishing of the semiconductor wafers, comprising cutouts for receiving the semiconductor wafers and passage openings for a polishing agent supplied during the polishing. Some of the passage openings are formed by holes which have a diameter of 2 to 8 mm and are arranged at a distance of 1 to 10 mm around the cutouts, wherein the holes are arranged on two central sections and an inner or an outer section of a circular path.