Patent ID: 6245148
Filing Date: 2001-06-12
Classification: B05C,H01L

Abstract:
A SOG dispensing system allowing for continuous production comprises;a source tank containing a SOG bottle having its input pipe line connected to a N.sub.2 source and inside the SOG bottle setting an output pipe line connected through a valve (V3) to input pipe line of following buffer tank;a buffer tank with its output pipe line connected through a valve (V7) to an input pipe line of following pump and inside wall thereof set three level sensors (Sb1, Sb2, Sb3) from low to high in this sequence, each detecting different level heights corresponding to their different volumes and then producing an alarm signal when volume of the buffer tank is below its low limit, a start signal for opening the valve (V3) to supply SOG into the buffer tank, and an alarm signal when volume of the buffer tank is above its high limit respectively;a pump with its output pipe line connected to input pipe line of following valve (V1) and another input pipe line connected through a valve (V4) to the top of the buffer tank;a pressure sensor, positioned at top and inside the buffer tank, producing a signal to open the valve (V4) allowing venting air from the top of the buffer tank to another output pipe line of the pump to reduce pressure of the buffer tank;a cooling unit surrounding the buffer tank to control its temperature between -1.degree. C. and 4.degree. C.; anda coating unit comprising a heating device, surrounding a segment of pipe line from input of valve (V1) to output of valve (V2) so as to allow for raising temperature of SOG therein from low temperature to room temperature, a valve (V1) controlled by a timing circuit to dispense a certain amount of SOG to a wafer, and a valve (V2) controlled by a detector to suck back residual SOG at the nozzle of its output pipe line, wherein input and output pipe lines of the valve (V1) are connected to output pipe line of the pump and input pipe line of the valve (V2) respectively.