Abstract: A semiconductor structure includes a conductive layer, an IMD layer and a plurality of protrusions. The IMD layer is formed on the conductive layer and has a first etch rate. Each protrusion includes an etching slowing layer, a lower electrode and a MTJ layer, wherein the etching slowing layer is formed on the IMD layer and has a second etch rate, the lower electrode passes through the IMD layer and the etching slowing layer, and the MTJ layer is formed on the lower electrode. The second etch rate is less than the first etch rate.

Abstract: A removal tool includes an elongate rod. A first end of the elongate rod is to be connected to and driven by a drive device, and a second end of the elongate rod is connected integrally to the first end. A direction from the first end toward the second end, which is substantially parallel to a longitudinal center axis of the elongate rod, is defined as a first direction. Along the first direction the second end is conically tapered and formed with plural splines which obliquely extend relative to the longitudinal center axis according a twist direction, wherein the twist direction generally conforms to a direction in which the removal tool is used to unfasten a fastener. Each spline has a circumferential surface having plural first teeth which obliquely extend relative to the longitudinal center axis according to the twist direction along the first direction.

Abstract: A removal tool includes an elongate rod. A first end of the elongate rod is to be connected to and driven by a drive device, and a second end of the elongate rod is connected integrally to the first end. A direction from the first end toward the second end, which is substantially parallel to a longitudinal center axis of the elongate rod, is defined as a first direction. Along the first direction the second end is conically tapered and formed with plural splines which obliquely extend relative to the longitudinal center axis according a twist direction, wherein the twist direction generally conforms to a direction in which the removal tool is used to unfasten a fastener. Each spline has a circumferential surface having plural first teeth which obliquely extend relative to the longitudinal center axis according to the twist direction along the first direction.