JPH02129100A - Equipment for heat treatment of semiconductor - Google Patents

Abstract

PURPOSE:To enable uniform heat treatment of a semiconductor wafer using an equipment with a simple constitution by connecting one end of a heat treatment unit through plural exhaust pipes with a common exhaust duct at a certain space and equipping the respective exhaust pipes with an exhaust-regulating valve having an angle detector and a controller. CONSTITUTION:Several steps of vertically arranged unit chambers respectively accommodating reaction tubes 1 and heaters 19 are placed in a box and the respective reaction tubes 1 are respectively connected through exhaust pipes 7 equipped with an exhaust-regulating valve 12 with an exhaust duct 8 at a certain space for discharge of gas exhausted to the exhaust duct 8 using an air blower 9 for exhalation. The exhaust-regulating valve 12 is equipped with a potentiometer 10 capable of detecting a closing angle of a closing valve and outputting the detected signal to a controller 17 for the exhaust regulating valves and the optimum angles for respective processes corresponding to each of plural exhaust-regulating valves 12 are preliminarily inputted to the controller 17 for drive control of the exhaust-regulating valves.

Description

DETAILED DESCRIPTION OF THE INVENTION (Objective of the Invention) (Industrial Application Field) The present invention relates to a semiconductor heat treatment apparatus used in a semiconductor wafer diffusion process.

(Prior Art) In FIG. 3 showing an example of a conventional semiconductor heat treatment apparatus,
Reaction tubes 1^, IB,
ICs and IDs are stored horizontally, and as the processing capacity increases, a box (not shown) in which unit chambers are provided in multiple stages is further installed adjacently horizontally.

The right end of each reaction tube is connected to an exhaust control valve 12A.
, 12B, , 12C, and 120, and are connected at intervals to a common exhaust duct 8 provided on the top surface of the box (not shown), and an exhaust blower 9 is connected to one end of the exhaust duct 8. ing.

In addition, semiconductor wafers (not shown) to be subjected to diffusion processing are housed in each reaction tube, and each reaction tube is housed in a cylindrical furnace made of heat insulating material provided in a unit chamber (not shown), with a gas inlet at the left end. A required amount of gas of a required type is supplied from a gas unit (not shown) connected to the reactor and is heated to a predetermined temperature by an electric heating device (not shown) provided on the inner wall of the furnace for heat treatment.

(Problem to be solved by the invention) However, in a semiconductor heat treatment apparatus with such a configuration,
Even if the pressure of the diffusion gas supplied from the left end is the same,
Since the pressure inside the exhaust duct 8 is higher as it moves upstream (that is, closer to the front in the figure), the flow rate of gas passing through each reaction tube is different.

Then, even if the temperature within each reaction tube is controlled uniformly, the quality of the processed semiconductor wafers becomes non-uniform.

Therefore, the inventor of the present invention previously published Japanese Patent Application No. 60-202981 (
In Japanese Unexamined Patent Publication No. 62-63421@), a semiconductor heat treatment apparatus as shown in FIG. 4 was proposed.

In FIG. 4, the middle part of the exhaust pipe 7 is connected between the exhaust port 2 provided in the opening/closing M3 attached to the right end opening 1b of the reaction tube 1 in the multistage unit chamber (not shown) and the right end exhaust duct 8. The exhaust control valve 12 and the flow rate sensor 13 are connected in series. The detection signal of the gas flow rate detected by the flow rate sensor 13 is input to the control device 14 equipped with a manual setting device 16, and the gas flow rate is input to the control device 14 equipped with a manual setting device 16.
1 control valve 12 is controlled to ensure uniform quality of semiconductor wafers.

However, the flow rate sensor 13 connected to the exhaust pipe 7 is likely to be attacked by hydrochloric acid contained in the high-temperature diffusion gas, so it has special specifications and is less readily available.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a semiconductor heat treatment apparatus that can uniformly perform diffusion treatment on a semiconductor wafer with a simple configuration.

(Structure of the Invention) (Means and Effects for Solving the Problems) The present invention provides a common exhaust duct in which a plurality of exhaust pipes are sequentially connected at intervals in the longitudinal direction of a common exhaust duct in which an exhaust device is provided on one side. In a semiconductor heat treatment equipment in which reaction tubes with the same supply gas conditions and heating conditions are connected to the exhaust pipes via exhaust control valves, each exhaust control valve is equipped with an opening/closing degree detector, and each of the plurality of exhaust control valves is This semiconductor heat treatment apparatus has a control device in which the optimum angle for each process is input in advance and drives and controls the exhaust control valve, thereby making the quality of the processed semiconductor wafers uniform.

(Example) Hereinafter, an example of the semiconductor heat treatment apparatus of the present invention will be described with reference to the drawings.

In Figure 1, the left end is the gas exhaust port 1 at the right end of the reaction tube 1.
An exhaust control valve 12 is connected to the middle part of the exhaust pipe 7, which is connected to the exhaust pipe 7 through the ball joint 6 and whose right end is connected to the exhaust duct 8. A potentiometer 10 is installed as an opening detector that detects the opening/closing angle of an on-off valve (not shown) and outputs the detection signal to an exhaust control valve control device 17. It is connected to the processing control device 18.

Further, a gas inlet 1a is provided at the left end of the reaction tube 1, through which a predetermined number of diffusion gases are supplied from a gas unit (not shown), and a boat 4 is inserted into the reaction tube 1. A semiconductor wafer 11 is placed on the reaction tube 1, and the outer periphery of the reaction tube 1 is surrounded by a heater 19 attached to the inner surface of a heat insulating material inside the unit chamber (not shown). , N5 which can be opened and closed freely is installed.

The unit chamber in which the reaction tubes 1 and the heater 19 are housed is arranged in a box (not shown) in four vertical stages, and the exhaust control valves 2 connected to each reaction tube 1 are connected to a common exhaust duct 8. The gases are connected at intervals and discharged into the exhaust duct 8 , and the gas is discharged by an intake blower 9 connected to one end of the exhaust duct 8 .

By the way, when heat-treating semiconductor wafers with a semiconductor heat-treating apparatus configured as described above, the optimum conditions for each processing step for various wafers are determined in advance as a model in one unit as shown in Fig. 1 before starting actual operation. .

That is, when finding the R-suitable conditions for a certain treatment step, for example, the supply period, temperature, and temperature of a predetermined type of gas supplied from the gas inlet port 1a of the reaction tube of the most upstream unit to the exhaust duct 8 are determined. By trial and error, find out the temperature inside the unit room, the opening degree of the exhaust control valve 12, etc. and,
During this work, the remaining units were to follow suit under the same conditions and the gas was also flowing.

Next, among the remaining units, the second unit connected to the next downstream
Note: Please operate the unit under the same conditions as above.
At this time, the first unit operates under the previously determined optimal conditions, and the remaining downstream units also operate while following the second unit. ) The throttle angle is determined by adjusting only the exhaust control valve 12.

Thereafter, in the same way, the exhaust control valves 12 of the remaining units are sequentially narrowed down (note: since they are connected to the downstream side of the exhaust duct 8 where the pressure is low, this is the direction of narrowing down), and the exhaust angle is adjusted in the meantime. Main processing control device 18 via valve control device 17
Enter each optimal amount angle in .

During actual operation, each exhaust control valve is driven and positioned for each processing step that has been input in advance to the main processing control device 18.

As a result, conditions other than the angle of the exhaust control valve 12 can be kept constant regardless of the position of the exhaust pipe 7 connected to the exhaust duct 8, so that semiconductor wafers can be uniformly processed with a simple configuration.

In the above embodiment, the reaction tube 1 was described as an example provided horizontally, but the same can be applied to a vertical type.

Furthermore, the processing control device 18 may be common to all units.

FIG. 2 shows another embodiment of the semiconductor heat treatment apparatus of the present invention.

In FIG. 2, the exhaust control valve control device 17 shown in FIG. The exhaust control valve 12 is driven and controlled.

In this case, there is an advantage that it becomes more practical when a microcomputer is employed in this device, which requires a reduction in the installation area.

(Effects of the Invention) As described above, according to the present invention, a number of exhaust pipes are connected at intervals to a common exhaust duct connected to an exhaust blower at one end via exhaust control valves. In a semiconductor heat treatment equipment in which a reaction tube is connected to each exhaust pipe, each exhaust control valve is equipped with an angle detector that detects the angle of the internal valve and outputs a detection signal, and the exhaust control valve is adjusted to the optimal angle in advance. Since we have installed a control device that inputs information on the angle of can.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing one embodiment of the semiconductor heat processing apparatus of the present invention, FIG. 2 is a partial sectional view showing another embodiment of the semiconductor heat processing apparatus of the present invention, and FIG. 3 is a conventional semiconductor heat processing apparatus. FIG. 4 is a partial sectional view showing the main part of FIG. 3. 1... Reaction tube 7... Exhaust pipe 8... Common exhaust duct 10... Potentiometer 11 as an angle detector.
...Exhaust control valve 12...Main processing control device 13.
...Exhaust control valve control vijJ device (8733) Agent: Yoshiaki Inomata, patent attorney (and 1 other person) Figure 1

Claims (1)

[Scope of Claims] A plurality of exhaust pipes are connected at intervals in the longitudinal direction of a common exhaust duct having an exhaust port at one end, and gas supply conditions and heating are controlled via an exhaust control valve to the exhaust pipes. In a semiconductor heat treatment apparatus in which reaction tubes having the same conditions are connected, an opening/closing angle detector provided in each of the exhaust control valves and an optimum angle for each process are input in advance for each of the plurality of exhaust control valves, and the exhaust gas A semiconductor heat treatment apparatus characterized by being provided with a control device that drives and controls a control valve.