A method of forming a semiconductor structure, includes forming a mixed rare earth oxide on silicon. A check is performed to determine the magnitude of the blade impedance at resonance. The low-weighted value manager divides a pulse width in response to a value of the lower nl bits of the n-bit digital data into fraction pulse widths, respectively adds the fraction pulse widths to the first pulses, and generates a second pulse-width-modulated signal having second pulses including the first pulse width and one of the fraction pulse widths. After removing the substrate, a transparent material is formed in direct contact with the aluminum-containing layer.