PROCESS OF PRODUCTION OF MASK WORKSTOCKS Russian patent published in 2003 - IPC

FIELD: electronics, production of mask workstocks based on one of key materials of microelectronics. SUBSTANCE: main feature of process lies in use at stage of preparation of glass plates of aqueous solutions of organic acids of common formula where R₁ = H, OH; R₂ = H, CH₃, CH₂COOH;; R₃ = H, CH₂COOH in certain sequence starting from acid with pKa = 3.12-3.13 with rise of this index with gradient ΔpKa = 0,7-1,05 at temperature 50-60 C and use of ultrasound with operational frequency 20-25 kHz with growth of the latter to 40-45 kHz. Concentration of aqueous solutions of organic acids amounts to 0.4-1.0 per cent by mass. Aqueous solution of lactic acid with concentration 0.4-1.0 per cent by mass and usage of ultrasound with operational frequency 40-45 kHz in the course of 2-3 min are employed in washing of masked chromium plates. Corrosive chemical elements are excluded from treatment of glass surfaces. EFFECT: exclusion of corrosive chemical media damaging surface of glass plate before and after deposition of masking layer. 1 cl, 1 tbl