Semiconductor wafer grinding apparatus

An apparatus for grinding semiconductor wafers comprising at least means for holding semiconductor wafers and means for grinding semiconductor wafers, wherein said means for holding semiconductor wafers comprises holder means having wafer-gripping surface for sucking and holding semiconductor wafers and liquid bearing means for rotatably supporting said holder means, said liquid bearing means having inclination control means formed therein, said inclination control means including first, second and third sets of inclination controlling areas for suspending said holder means, each having first and second pockets formed at upper and lower levels, said first set of inclination controlling area having a first flow rate control means connected thereto, said second set of inclination controlling area having a second flow rate control means connected thereto, and said third set of inclination controlling area having a third flow rate control means, whereby the parallelism of said wafer-gripping surface relative to said means for grinding semiconductor wafers is assured by controlling the flow rate of the liquid to each of said first, second and third sets of inclination controlling areas.