Fabrication of digitalized spin coater for deposition of thin films

This paper describes the fabrication of digitalized spin coating system to deposit thin films on glass substrate. The digitalized spin coating system has been integrated with an automatic control arrangement, where a microcontroller unit, a character display, a matrix keypad and a dc motor has been employed. A dc motor has been used to spin the substrate. It is needed a controlling circuit to maintain the desired speed. To give control pulse to microcontroller, which has overcome the difficulty of conventional SCR based controlling circuit. It is possible to rise up the speed of the motor from 0 to 3300 rpm. The required speed (in rpm) and spinning time can be given as input from the matrix keypad. LCD Character display plays the role of showing the desired rpm and time. Zinc oxide thin films have been deposited on glass substrate with the proposed digitalized spin coater. It has important features that it can operate immediately at different speed and time after finishing the previous settings. This system is very simple, light and cheap in price.