MATERIAL VAPORIZATION SUPPLY DEVICE EQUIPPED WITH MATERIAL CONCENTRATION DETECTION MECHANISM

摘要

The purpose of the present invention is to accurately adjust the material concentration in gas mixture of carrier gas and material gas while making it possible to stably supply the gas mixture to a process chamber under highly accurate flow control, to simply and accurately detect the material gas vapor concentration in the gas mixture without using an expensive concentration meter and so forth, and to display the concentration in real time. The present invention provides a material vaporization supply device in which carrier gas (GK) is supplied to a source tank (5) through a mass flow controller (3) and the carrier gas (GK) is discharged from the source tank (5) while a gas mixture (GS) of saturated vapor (G) of a material (4) generated by keeping the source tank (5) at a constant temperature with a thermostatic section and said carrier gas (GK) is supplied to a process chamber. An automatic pressure control device (8) is provided at an outflow passage for the gas mixture (GS) flowing from said source tank (5) while a mass flow meter (9) is provided on the downstream side of the automatic pressure control device (8). The opening and closing of a control valve (8a) of said automatic pressure control device (8) is controlled so as to keep an internal pressure (Po) in the source tank (5) at a prescribed value. Detection values including the flow volume (Q1) of the carrier gas (GK) through said mass flow controller (3), said tank internal pressure (Po) and the flow volume (Qs) of the gas mixture (Gs) through said mass flow meter (9) are input into a material concentration computation unit (10). The material concentration computation unit (10) calculates a material flow volume (Q2) as Q2 = Qs × PMO/PO (where PMO is the saturated vapor pressure of a material vapor (G) at source tank temperature t°C). A material gas vapor concentration (K) in the gas mixture (Gs) supplied to said process chamber is calculated as K = Q2/Qs using the material flow volume (Q2) and displayed.