The disclosed nucleic acid primer sets, used in combination with quantitative amplification of tissue cDNA, can indicate the presence of specific proteases in a tissue sample. A resonant tank circuit that includes an inductive element, a first resonance capacitor, and a second resonance capacitor, is coupled to the half-bridge converter to receive the square wave voltage such that a generally sinusoidal AC voltage is produced across the second resonance capacitor. The second step includes alternately repeating an organic film forming process whereby an organic film is deposited on the inner surface of the recess with a second plasma, and an etching process whereby the recess covered with the organic film is anisotropically etched with the first plasma.