JPH0342030A - Fluid supply equipment - Google Patents

Abstract

PURPOSE:To make the temp. difference between the temp. of supplied fluid in a supply member and the set temp. of a heat exchanger to be minimum by providing a preliminary heating means to heat the fluid in a tank in the preceding stage of a heat exchanger. CONSTITUTION:The fluid stored in a tank 1 is introduced into a heat exchanger 2 to be heated in a specified temp. and is discharged. The supply member 4 connected with the heat exchanger 2 through a conduct 3 supplies the heated fluid discharged from the heat exchanger 2. In this case, the fluid in the tank 1 is heated in the preceding stage of the heat exchanger 2 by a preliminary heating means 7. As a result, the temp. difference between the supplied temp. of the fluid in the supply member and the set temp. in the heat exchanger is made to be minimum, and the temp. of the fluid in the supply member is stabilized.

Description

[Detailed description of the invention]

[Summary] For example, it relates to a fluid supply device that supplies a fluid such as an etching solution used for etching wafers in the manufacture of semiconductor devices, and in detail, it relates to temperature management of the fluid, and the supply temperature and heat of the fluid in the supply member. The purpose is to provide a fluid supply device that can minimize the temperature difference from the set temperature of the exchanger, and includes a tank for storing fluid, the fluid is guided from the tank, heated to a desired temperature, and discharged. and a supply member connected to the heat exchanger via a lead-out pipe and for supplying heated fluid discharged from the heat exchanger. A preheating means for heating the fluid in the tank is provided at the front stage of the tank. [Industrial Field of Application 1] The present invention relates to a fluid supply device for supplying a fluid such as an etching solution used for etching a wafer in manufacturing a semiconductor device, and specifically relates to temperature control of the fluid. be. For example, wet etching using an etching liquid is used to process stepped shapes such as wiring and element patterns in the wafer process of semiconductor devices because it causes no damage to the product. With the modernization of processing equipment and process needs, wet etching has changed from manual visual inspection to immersing multiple wafers in a large amount of etching solution (
Furthermore, because the liquid quality of the etching solution changes in dimple-type etching, the process has shifted to single-wafer etching, in which the etching solution is supplied by a nozzle spray while rotating the wafer. There is. In this wet etching, the film thickness that can be processed within a certain period of time changes depending on the temperature of the etching liquid, that is, the etching rate changes, so it is necessary to control the etching liquid to a desired constant temperature using a heat exchanger etc. be.

[Conventional technology]

Conventionally, for example, a chemical supply device used for wet etching in the processing of semiconductor devices has a tank 1 for storing a prepared etching solution as shown in FIG. 5, and a tank 1 for guiding the etching solution to a desired level. a heat exchanger 2 that heats the temperature to a temperature of
A nozzle 4 for intermittently supplying the heated etching liquid discharged from the heat exchanger 2.
It is composed of. The outlet pipe 3 is shown in Fig. 6 (al, (
As shown in b), it is composed of an inner tube 3a through which the etching solution flows, and an outer tube 3b which accommodates the inner tube 3a and allows constant temperature water to flow through.
I wrap it around it to keep it warm. Further, a thermocouple 6 for detecting the temperature of the etching liquid is provided in the outlet pipe 3 near the outlet of the heat exchanger 2, and the detection result of the thermocouple 6 is fed back and the etching liquid is discharged from the heat exchanger 2. The temperature of the etching solution is brought closer to the set temperature. [Problems to be Solved by the Invention] However, in the chemical solution supply device described above, the etching solution supplied from the nozzle 4 is not continuously supplied in a fixed amount for a fixed period of time, but is supplied intermittently. Also, the supply interval for supplying the etching solution is influenced by the capacity of the heat exchanger 2. Moreover, when the thermocouple 6 is provided near the outlet of the heat exchanger 2, there is a problem that a temperature difference occurs between the supply temperature of the etching liquid at the tip of the nozzle 4 and the set temperature of the heat exchanger 2. The present invention has been made to solve the above problems, and its purpose is to minimize the temperature difference between the supply temperature of the fluid in the supply member and the set temperature of the heat exchanger. An object of the present invention is to provide a fluid supply device. [Means for Solving the Problems] FIG. 1 is a diagram illustrating the principle of the present invention. The tank 1 is for storing fluid, and the preheating means 7
The fluid in the tank 1 is heated in advance before the heat exchanger 2. The heat exchanger 2 heats the fluid led from the tank 1 to a desired temperature and discharges the fluid. The supply member 4 is connected to the heat exchanger 2 via the outlet pipe 3, and supplies heated fluid discharged from the heat exchanger 2. [Operation] A theoretical equation for heat transfer in a diaphragm heat exchanger is expressed by the following equation (2). Δt-Δt1.8-DKF Δt; Temperature difference between the fluid and constant-temperature water at distance F from the population of the heat exchanger ΔtIi Temperature difference D between the fluid and constant-temperature water at the inlet of the heat exchanger; constant, (17G ^・Cp^)±(1/G a
-CPB )K; Heat transfer rate F; Distance from the inlet of the heat exchanger G: Mass velocity per hour (flow rate) CP; Specific heat at constant pressure In the present invention, the fluid in the tank is heated in advance by preheating means at the front stage of the heat exchanger. Since this is heated, guided to a heat exchanger, heated to a desired temperature, and discharged, Δt1 in equation (2) can be reduced. As a result, the temperature difference (Δt) between the outlet pipes of the heat exchanger can be brought close to 0° C., and the temperature of the fluid in the supply member can be stabilized. [Example 1] Hereinafter, an example embodying the present invention will be described with reference to FIGS. 2 to 4. Fig. 2 is a schematic configuration diagram showing an embodiment of the present invention in a chemical supply device for etching, Fig. 3 is a cross-sectional view in the diametrical direction of the lead-out pipe, and Fig. 4 is a cross-sectional view in the axial direction of the lead-out pipe. 5, the same components as in FIG. 5 will be described with the same reference numerals. As shown in Fig. 2, a heating cylinder 7 as a preheating means is arranged to accommodate a tank 1 storing an etching solution, and constant temperature water is introduced into the heating cylinder 7 from a heat exchanger 2 and circulated. has been done. As a result, the etching liquid in the tank 1 is heated in advance. The heat exchanger 2 includes a spiral heating tube 2a placed in constant-temperature water, and the heating tube 2a heats the etching liquid introduced from the tank 1 via the introduction tube 8 to a set temperature and discharges it. The etching liquid heated by the heat exchanger 2 and discharged is guided through the outlet pipe 3 to a nozzle 4 serving as a supply member. As shown in Fig. 3.4, the outlet pipe 3 has a triple structure consisting of an inner pipe 3c + a central pipe 3d and an outer pipe 3e.
The etching solution is passed between the inner tube 3d and the inner tube 3d.
Constant-temperature water led from the heat exchanger 2 is made to flow between the center tube 3d and the outer tube 38. A spacer 3f is provided between each tube. Teflon material with a high heat transmission rate is used for the central pipe 3d, and the constant temperature water that flows between the inner pipe 3c, the central pipe 3d, and the outer pipe 38 flows between the inner pipe 3c and the central pipe 3d. The etching solution is heated to keep it warm. As shown in FIG. 4, a cap 9 is fixed to the end of the outer tube 3e, and a discharge tube 10 for returning constant temperature water to the heat exchanger 2 is connected to the cap 9, and a central tube 3d passes through the cap 9. has been done. A cap 11 is fixed to the end of the central tube 3d, and a chemical solution supply tube 12 is connected to the cap 11. Further, an inner tube 3c passes through the cap 11 and is connected to the heat exchanger 2, so that constant temperature water is returned to the heat exchanger 2. A nozzle 4 is connected to the chemical liquid supply pipe 12 via a switching valve 13, as shown in FIG. Further, the switching valve 13 is provided with a return pipe 14 for returning the etching liquid to the tank side. When the etching liquid is not supplied from the nozzle 4, the switching valve 13 is switched to the return pipe 14 side so that the etching liquid heated to a predetermined temperature by the heat exchanger 2 is returned to the tank 1. In this way, in this embodiment, the heating cylinder 7 that houses the tank 1
Since the etching liquid in the tank 1 is heated in advance by circulating constant temperature water in the heating cylinder 7, the temperature change from the set temperature in the heat exchanger 2 can be minimized. That is, the capacity of the heat exchanger 2 can be substantially improved, and even when the amount of etching liquid discharged from the heat exchanger 2 increases, the temperature of the etching liquid can be reliably maintained at the set temperature. can. Further, in this embodiment, when the etching liquid is not being supplied from the nozzle 4, the switching valve 13 is switched to the return pipe 14 side,
Since the etching liquid is returned to the tank 1 and circulated, the temperature of the etching liquid in the outlet pipe 3 leading to the switching valve 13 can be set to the set temperature of the heat exchanger 2, so that the etching liquid is supplied from the nozzle 4. It is possible to almost eliminate the temperature drop of the etching solution. Furthermore, in this embodiment, the outlet pipe 3 is an inner pipe 3c, a central pipe 3d,
and an outer pipe 3e, an inner pipe 3c and a central pipe 3d.
An etching solution is passed between the inner tube 3c and the central tube 3.
Since the constant temperature water is made to flow between the inner tube 3c and the outer tube 30, the etching liquid discharged from the heat exchanger 2 and flowing between the inner tube 3c and the central tube 3d is passed between the inner tube 3c and the central tube 3d. It can be heated by the constant temperature water flowing between the outer tube 30 and the outer tube 30, and a drop in temperature can be reliably prevented. In this embodiment, three configurations are used: (1) A heating tube 7 is provided to preheat the etching liquid in the tank (1); (2) The outlet tube 3 has a triple structure consisting of an inner tube 3c, a central tube 3d, and an outer tube 3e. , the etching liquid flowing between the inner tube 3c and the central tube 3d is warmed by the constant temperature water flowing between the inner tube 3c, the central tube 3d and the outer tube 36.■ The etching liquid is supplied from the nozzle 4. When the etching liquid is not supplied to the tank 1, the switching valve 13 is switched to the return pipe 14 side to return the etching liquid discharged from the heat exchanger 2 to the tank 1.
One may be adopted. Further, the inlet pipe 8 may have a triple structure like the outlet pipe 3. In addition, in order to further prevent the temperature of the etching liquid discharged from the heat exchanger 2 from decreasing, the outlet tube 3 may be shortened, that is, the distance between the heat exchanger 2 and the nozzle 4 may be shortened, and the outlet tube 3 may be shortened. A heat insulating material or the like may be wrapped around the outer periphery of 3. Furthermore, although the return pipe 14 is returned to the tank 1 in this embodiment, it may be connected to the introduction pipe 8 as shown by the two-dot chain line in FIG. Further, in this embodiment, the present invention is applied to an etching chemical supply device, but it may also be applied to a supply device for raw material liquid for processing, other liquids, or fluids such as gas, whose supply temperature needs to be adjusted. . . [Effects of the Invention] As detailed above, according to the present invention, there is an excellent effect that the temperature difference between the supply temperature of the fluid in the supply member and the set temperature of the heat exchanger can be minimized.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention, FIG. 2 is a schematic configuration diagram showing an embodiment of the present invention in an etching chemical supply device, and FIG. 3 is a sectional view in the diameter direction of the outlet pipe. FIG. 4 is a cross-sectional view of the outlet tube in the axial direction, FIG. 5 is a schematic configuration diagram showing a conventional chemical liquid supply device, FIG. It is a sectional view in the axial direction of a conventional outlet pipe. In the figure, l is a tank, 2 is a heat exchanger, 2 is an outlet pipe, 3G is an inner pipe, 3d is a central pipe, 3e is an outer pipe, and 4 is a supply member. 7 is a heating tube as a preheating means, and 14 is a return pipe.

Claims (1)

[Scope of Claims] 1. A tank (1) that stores a fluid; a heat exchanger (2) that leads the fluid from the tank (1), heats it to a desired temperature, and discharges it; and the heat exchanger (2). ) via the outlet pipe (3),
and a supply member (4) for supplying heated fluid discharged from the heat exchanger (2), the fluid in the tank (1) at a stage upstream of the heat exchanger (2). A fluid supply device characterized in that it is provided with preheating means (7) for heating the fluid. 2. A tank (1) for storing fluid; a heat exchanger (2) for guiding the fluid from the tank (1), heating it to a desired temperature and discharging it; and a lead-out pipe (3) to the heat exchanger (2). ),
and a supply member (4) for supplying the heated fluid discharged from the heat exchanger (2), wherein the fluid heated and led out by the heat exchanger (2) is
A fluid supply device characterized by being provided with a return pipe (14) that returns to the tank (1) at least when the supply member (4) is not supplying. 3. A tank (1) for storing fluid; a heat exchanger (2) for guiding the fluid from the tank (1), heating it to a desired temperature and discharging it; and a lead-out pipe (3) to the heat exchanger (2). ),
and a supply member (4) for supplying heated fluid discharged from the heat exchanger (2), wherein the outlet pipe (3) is connected to an inner pipe (3c), a central pipe (3d) and an outer tube (3e), the fluid flows between the inner tube (3c) and the central tube (3d), and the fluid flows between the inner tube (3c), the central tube (3d), and the outer tube (3d). 3e) A fluid supply device characterized in that constant temperature water is allowed to flow between the fluid supply devices.