FIELD: microelectronics; quality control of gate dielectrics, masking, protecting, or insulating layers. SUBSTANCE: method involves measurements of film refractive index by means of ellipsometer. Prior to measurements dc voltage is applied to film perpendicular to its surface for 90-120 minutes voltage magnitude being higher by 10-50 times than breakdown value. Degree of film damage is recognized by rate of change of refractive index of film upon de-energizing the latter. EFFECT: enhanced sensitivity due to eliminating shielding effect of impurities. 1 tbl
