Removal of OH− absorption band in Al(PO3)3–B2O3–AlF3 glasses and their applications to MOS capacitors

Absorption coefficient and reflectivity in peak of OH− absorption around 3500 cm−1 in Al(PO3)3–B2O3–Al2O3 and Al(PO3)3–B2O3–AlF3 glass systems were calculated by the use of equations derived from Kobayashi. The addition of AlF3 to aluminoborophosphate glasses and the treatment of dry-air-bubbling during melting decreased markedly absorption coefficient and reflectivity of OH− bands. Reflectivity of OH− bands increased with increasing absorption coefficient. The ΔVg shifts and the increase of hysteresis MOS capacitors are related to OH− concentration in glasses.