DEVICE TO DETERMINE THICKNESS AND OPTICAL PROPERTIES OF LAYERS IN PROCESS OF THEIR FORMATION Russian patent published in 1995 - IPC

FIELD: measurement technology. SUBSTANCE: device includes optical unit housing radiation source, beam splitting mirror positioned in succession along flight of beam passing from source through beam splitting mirror, interferential filter, first lens, first photodetector located in series along flight of beam reflected from beam splitting mirror towards forming layer and again passed through beam splitting mirror, second photodetector incorporating first and second D.C. amplifiers which outputs are connected to system of signal registration and processing. Device is supplemented with 1R light filter put in front of second interferential light filter, first polarizer, located in front of first interferential light filter, second polarizer positioned ahead of 1R filter, unit of visual tuning, first and second preamplifiers. Surfaces of lenses are made frosted. Second polarizer, 1R filter, second interferential filter, second lens, second photodetector and second preamplifier are fixed rigidly relative to each other in metal case mounted for rotation about axis of beam passing though listed optical elements, first polarizer, first interferential filter, first lens, first photodetector and first preamplifier are fixed rigidly relative each other in metal case mounted for rotation about axis of beam passing through listed optical elements. Unit of visual tuning has plate with guiding grooves and hole to let through radiation of light source mounted for movement and registration of position with reference to beam, film put into grooves of plate for movement and having two fixed positions which carries metal case housing second photodetector and target in the form of frosted glass disc with crossed hairs. Output of first photodetector is connected to input of first preamplifier which output is linked to input of first amplifier. Output of second photodetector is connected to input of second preamplifier which output is linked to input of second amplifier. EFFECT: enhanced accuracy of determination of thickness and optical properties of layers. 2 cl, 3 dwg