a method of forming a shallow trench isolation region in a silicon wafer which results in the elimination of long range slip dislocations in the wafer and reduces leakage current across the isolation regions . long shallow trenches are formed in a silicon wafer at a 45 degree angle to the plane of the wafer . this is achieved by moving the primary flat of the wafer to the plane prior to the formation of the trenches , which causes the bottom edges of the long trenches to intersect with several planes , so that stresses do not propagate along any one single plane . the trenches are then filled with an insulative material , such as oxide .