Abstract: Disclosed are a phase distortion compensating apparatus and method for reducing a torque ripple in a 3-phase motor using four switching elements, which are capable of adjusting respective switching times of phase voltages, to be supplied to the 3-phase motor by an inverter including the switching elements, based on a voltage difference between upper and lower DC link capacitors respectively adapted to supply voltages to the inverter, thereby reducing a torque ripple generated in the motor.

Abstract: Disclosed are a voltage compensating apparatus and method for a 3-phase inverter using four switches, to compensate for a severe distortion of a 3-phase application voltage due to a voltage ripple.

Abstract: An improved method for forming a capacitor which is capable of increasing cell capacitance is disclosed. The capacitor easily formed a sequential two-step etching processes. The two-step etching include a selectively etching to form the contact hole for exposing an etch stop layer between gate electrodes, and an isotopically dry etching to maximize capacitor surface area without cleaning process after the selectively etching, an interlayer insulating layer being patterned in a manner which produces inner interlayer contact sidewalls having standing wave ripples and removes the exposed etch stop layer. As a result, it is found that the capacitor which is obtained by a simple and easy two-step dry etching exhibits an increased capacitor surface area. Furthermore, it is possible to form the stacked capacitor having sufficiently high storage capacitance without increasing the contact resistance.