Device for supplying the liquid material inside a filling container and method of controlling the liquid level inside the filling container for said liquid material supply device
Disclosed are methods and apparatuses for supplying a liquid and controlling its level inside of a container. In particular, the liquid inside of the container may be a liquid material suitable for use in a chemical vapor deposition process, wherein the liquid is controlled and supplied in a manner which minimizes the introduction of impurities.
1. A device for supplying liquid material inside a filling container, wherein the device is provided with:
a filling container into which a predetermined amount of liquid material is filled,
a carrier gas introduction flow path through which carrier gas accompanying the liquid material inside the filling container is introduced,
a liquid material supply flow path through which liquid material is supplied by being accompanied by the carrier gas,
a constant quantity feeder provided on an upper part of the filling container and having a set internal volume,
a liquid material refill flow path for refilling with liquid material, having one end connected to the constant quantity feeder,
pipe La having one end connected to a lower part of the constant quantity feeder and the other end immersed inside the liquid layer of the liquid material inside the filling container,
pipe Lb having one end connected to the upper part of the constant quantity feeder and the other end located above liquid level inside the filling container,
on-off valve Va located between the constant quantity feeder and pipe La,
on-off valve Vb located between the constant quantity feeder and pipe Lb,
a control unit adapted to introduce carrier gas into the filling container and supply liquid material by being accompanied by the carrier gas and, at the same time, adapted to fill the liquid material into the constant quantity feeder by opening the liquid material refill flow path and refill into the filling container the liquid material inside the constant quantity feeder by simultaneously opening on-off valves Va and Vb,
a branch flow path Lc branching the flow path between the constant quantity feeder and on-off valve Vb,
flow path Ld which enables inert gas supply, connected to the branch flow path Lc, and
on-off valve Vc located between one end of flow path Ld and branch flow path Lc,
wherein the device supplies inert gas to flow path Ld upon refilling with liquid material and, at the same time, wherein the liquid material remaining inside the constant quantity feeder, pipe La, and pipe Lb is refilled into the filling container while on-off valve Vc is open.
2. The device for supplying liquid material inside a filling container of claim 1 , wherein the flow path Ld has a predetermined internal volume, further comprising:
an on-off valve Vd located at the other end of flow path Ld,
pressure gauge Pc located on the branch flow path Lc, and
pressure gauge Pd located on the flow path Ld,
wherein the device measures the volume of the liquid material inside the constant quantity feeder from the indicated value of pressure gauge Pd when the flow path Ld is under predetermined pressure conditions and the indicated value of pressure gauge Pc before and after opening and closing on-off valve Vc.
3. The device for supplying liquid material inside a filling container of claim 1 , further comprising:
a storage container in which one end of the liquid material refill flow path is immersed inside a liquid layer of liquid material stored therein, and
an inert gas supply flow path Le supplying inert gas from a vertex unit of the storage container,
wherein liquid material refills into the constant quantity feeder by means of the supply pressure of the inert gas from the inert gas supply flow path Le.
4. A method of controlling a liquid level inside a filling container by supplying a predetermined amount of liquid material and a carrier gas into the filling container from a liquid material supply device, the method comprising:
filling the liquid material into a constant quantity feeder, the constant quantity feeder having a set internal volume and located on an upper part of the filling container,
refilling into the filling container the liquid material inside the constant quantity feeder, and
controlling the liquid level inside the filling container so as to become constant by connecting a lower end unit of the constant quantity feeder inside a liquid layer of the liquid material inside the filling container via pipe La and simultaneously connecting an upper end unit of the constant quantity feeder to the interspace above the liquid layer upper part via pipe Lb, wherein the controlling the liquid level inside the filling container so as to become constant step comprises:
(1) when known amounts of liquid material are supplied by means of the carrier gas to a consumption device, filling the liquid material into the constant quantity feeder at regular intervals, and refilling into the filling container the liquid material inside the constant quantity feeder;
(2) when an undefined amount of liquid material is supplied by means of the carrier gas to the consumption device, monitoring a pressure inside the filling container, filling liquid material into the constant quantity feeder, and predicting a position of the liquid level from a pressure value before and after refilling the liquid material inside the filling container; in case of excess amounts, discontinuing refilling; in case of insufficient amounts, filling the insufficient amount of liquid material into the constant quantity feeder and refilling into the filling container the liquid material inside the constant quantity feeder.
5. The method of controlling the liquid level inside a filling container of claim 4 , wherein the controlling the liquid level inside the filling container so as to become constant step further comprises:
blocking a connectable flow path Ld having a predetermined internal volume, the connectable flow path Ld connected to branch flow path Lc located on the upper part of the constant quantity feed, and
determining a volume of the liquid material inside the constant quantity feeder from (1) a pressure of flow path Ld under conditions of predetermined pressure obtained by means of inert gas and (2) a pressure of flow path Ld after the constant quantity feeder and flow path Ld have been connected, and
when no liquid volume is determined, repeating the controlling step of claim 4 ;
when liquid volume is determined, from a state wherein flow path Ld is under predetermined pressure conditions, connecting constant quantity feeder and flow path Ld, refilling the filling container with the liquid material remaining inside the constant quantity feeder, pipe La, and pipe Lb, and repeating the controlling step of claim 4 .