JPS63200213A - Generating device for gas flow rate setting signal - Google Patents

Abstract

PURPOSE:To quickly set and control a gas flow rate control device by adding plural setting signal generators to a setting signal generating circuit together with a selection circuit which selects those setting signals and sends them to a transmission part. CONSTITUTION:A gas flow rate setting signal generating device contains a setting signal generating circuit 1 which produces the electrical setting signals S and a transmission line 2 which transmits these signals S to a gas flow rate control device 3 as the gas flow rate setting signals M. Then two setting signal generators 5A and 5B connected to a DC constant voltage source 4 are added to the circuit 1 together with a selection signal 6 which selects the setting signals received from both generators 5A and 5B and sends the selected signal to the line 2. Thus, the setting signals of different values are obtained from both generators 5A and 5B and selected by the circuit 6. Then, a selected setting signal is sent to the line 2. As a result, said setting signals can be transmitted successively and continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a gas flow rate control device whose opening degree is to be controlled by sequentially changing values, from one opening degree to another. The present invention relates to a gas flow rate setting signal generating device that generates a gas flow rate setting signal for controlling the setting of a gas flow rate.

Conventional technology Conventionally, the same element is used,
A plurality of semiconductor layers having mutually different compositions are formed by vapor phase epitaxy (VPE) or chemical vapor deposition (CVD),
Continuous formation by laminating is practiced.

In this case, the opening degree of one raw material gas using the same raw material gas is controlled by the electrical gas flow rate setting signal from the gas flow rate setting signal generator for the flow rate of that one raw material gas. Using a gas flow cooling control device, the set flow rate is sequentially switched and supplied to the reaction path.

In this case, a gas flow rate setting signal generator having the configuration described below with reference to FIG. 2 has been proposed.

That is, a setting signal generation circuit 1 that generates an electrical setting signal S, a transmission line 2 that transmits the setting signal S from the setting signal generator 1 to the gas flow device 3 as a gas flow rate setting signal M; has.

In this case, the setting signal generation circuit 1 has a configuration in which a DC constant voltage power supply 4 is connected to one setting signal generator 5 which is a variable voltage divider having a potentiometer configuration.

According to such a gas flow rate setting signal generator, by manually moving the setting signal generator 5 of the setting signal generating circuit 5 from the first position to the second position, the setting signal S is changed to the first voltage. It can be obtained as changing from the voltage value to the second voltage value.

Further, the setting signal S obtained in this manner can be transmitted as a gas flow rate setting signal M that changes from the first value to the second value depending on the order of the gas flow 8 control and control device 3 through the transmission line 2. can.

Therefore, the gas flow ff1l control device 3 can be set and controlled from the first opening degree to the second opening degree, and therefore the flow rate of the raw material gas can be changed from the first flow rate value to the second flow rate value. can be switched to

Therefore, using the gas flow rate setting signal generator described above,
Two semiconductor layers using the same element but having different compositions can be successively formed by stacking them by vapor phase growth or chemical vapor deposition.

However, in the case of the above-mentioned gas flow direction setting signal generator, the gas flow setting signal M that sequentially changes from the first value to the second value is the setting signal of one setting signal generation circuit 1. By manually operating the signal generator 5, the setting signal generation circuit 1
Since the setting signal S is obtained from the gas flow rate setting signal M, it takes a relatively long time for the gas flow rate setting signal M to change from the first value to the second value.

Therefore, as described above, by using the gas flow rate setting signal generator shown in FIG.
When two semiconductor layers are stacked, a relatively thick transition region is formed between the two semiconductor layers.

SUMMARY OF THE INVENTION In order to solve the problem, the present invention proposes a new gas flow setting signal generator which does not have the above-mentioned drawbacks.

The gas flow direction setting signal generating device according to the present invention, as in the case of the conventional gas flow rate setting signal generating device, includes a setting signal generating circuit that generates an electrical setting signal, and a setting signal from the setting signal generating circuit. and a transmission path for transmitting a gas flow m setting signal to the flow rate control device.

However, in the gas flow rate setting signal generation device according to the present invention, in the gas flow rate setting signal generation device having such a configuration, the setting signal generation circuit includes a plurality of setting signal generators and a plurality of setting signal generators. and a selection circuit that selects the plurality of setting signals obtained respectively and sends the selected setting signals to the transmission section.

According to the gas flow rate setting signal generating device according to the present invention, it is possible to obtain a plurality of setting signals having mutually different values from the plurality of setting signal generators of the setting signal generating circuit.

Also, the selection circuit selects one of the plurality of setting signals.
It is possible to select one and send the selected setting signal to the transmission path.

Therefore, by sequentially selecting a plurality of setting signals having mutually different values one by one by the selection circuit, the plurality of setting signals having mutually different values are sequentially and continuously applied to the gas flow rate control device. In addition, it can be transmitted as a gas flow rate setting signal.

In this case, the gas flow rate setting signal transmitted to the gas flow ffi III all device is selected from one of the plurality of setting signals having mutually different values by the selection circuit.
It is obtained as if the value is changing at the speed when selecting one. On the other hand, the speed at which the selection circuit selects one of the plurality of setting signals having different values from the other is determined by the setting in the conventional gas flow rate setting signal generator described above in FIG. By the signal generator 5,
The speed can be significantly increased compared to the speed at which the setting signal is changed from one value to another.

Therefore, the gas flow m setting signal transmitted to the gas flow m control device with successive values can be obtained as rapidly changing from one value to another.

Therefore, the gas flow m control device in which the opening degree is set and controlled by sequentially changing the value can be rapidly set and controlled from one opening degree to another opening degree.

In addition, before selecting one of the plurality of setting signals having different values from each other by the selection circuit, a setting signal generator for obtaining the latter setting signal is connected in advance to the setting signal. Since the signal can be adjusted so that it is obtained at a scheduled value, the gas flow setting signal that is transmitted by sequentially changing the value to the gas flow 1 control chamber can be changed from that one value to the other scheduled value. can be obtained as if the value is changing immediately.

Embodiment Next, an embodiment of the gas flow m setting signal generator according to the present invention will be described with reference to FIG.

In FIG. 1, parts corresponding to those in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

The gas flow m setting signal generator according to the present invention shown in FIG.
As in the case of the conventional gas flow setting signal generator shown in Fig. 1 (above), there is a setting signal generating circuit 1 that generates an electrical setting signal, and a setting signal S of the setting signal generating circuit 1.
and a transmission line 2 for transmitting the signal to the gas flow rate control device 3 as a gas flow setting signal M.

However, in the case of the gas flow rate setting signal generating device according to the present invention shown in FIG. 1, the setting signal generating circuit 1 is connected to the setting signal generator 5 described above in FIG.
The two setting signal generators 5A and 5B similar to the above and the setting signals SA and SB obtained from these two setting signal generators 5A and 5B are selected, and the selected setting signals are sent to the transmission line 2. and a selection circuit 6.

The above is the configuration of the embodiment of the gas flow m setting signal generating device according to the present invention.

According to the gas flow rate setting signal generator according to the present invention having such a configuration, by adjusting the two setting signal generators 5A and 5B of the setting signal generating circuit 1 in advance, the setting signal generators 5A and 5B can be adjusted in advance. Setting signals SA and SB obtained from 5B can be obtained with mutually different values.

Further, the setting signal S obtained from the setting signal generators 5A and 5B by the selection circuit 6 of the setting signal generating circuit 1, respectively.
One of A and 8B can be selected and the selected setting signal can be sent to the transmission path 2.

Therefore, by sequentially selecting the setting signals SA and SB obtained from the setting signal generators 5A and 5B one by one by the selection circuit 6, the setting signals SA and SB are continuously transmitted to the gas flow m control device 3. can be transmitted as a gas flow m setting signal M.

In this case, the gas flow rate setting signal M transmitted to the gas flow m control device 3 is used when the selection circuit 6 selects one of the setting signals SA and SB having mutually different values. It is obtained as if the value is changing at a speed of .

On the other hand, the speed at which the selection circuit 6 selects one of the setting signals SA and SB having different values from the other is different from that of the conventional gas flow m described above in FIG. This is much faster than the speed at which the setting signal S is changed from one value to another by the setting signal generator 5 in the setting signal generator.

Therefore, the gas flow rate setting signal that is transmitted to the gas flow m control device 3 while changing its value sequentially can be obtained as rapidly changing from one value to another value.

Therefore, the gas flow rate control device 3, whose opening degree is set and controlled by sequentially changing the value, can be rapidly set and controlled from one opening degree to another opening degree.

Furthermore, before the selection circuit 6 selects one of the setting signals SA and SS having different values from the other, the setting signal generators 5A and 5B for obtaining the latter setting signal are selected. One can be adjusted so that the setting signal (one of the setting signals SA and SS) from it is obtained at a predetermined value, so the value is sequentially changed and transmitted to the gas flow rate control device 3. The gas flow setting signal M can be obtained as changing immediately from one value to another predetermined value.

Therefore, the gas flow rate control device 3 can be rapidly set and controlled from the first opening degree to the scheduled second opening degree.

Therefore, when the gas flow m setting signal generator according to the present invention shown in FIG. 1 is used as described above in conjunction with the conventional gas flow ffi setting signal generator shown in FIG. When two semiconductor layers using elements but having mutually different compositions are successively formed by stacking them by vapor phase growth or chemical vapor deposition, the two semiconductor layers having mutually different compositions are Only a transition region is formed between the semiconductor layers, which has a much smaller thickness than when using the conventional gas flow m setting signal generator described above in FIG.

Incidentally, the gas flow rate setting signal generator according to the present invention shown in FIG. When formed, only a very thin transition region was formed between the two semiconductor layers, as shown in FIG. 3A. On the other hand,
When the same two semiconductor layers are formed under the same conditions using the conventional gas flow ffi setting signal generator described above in FIG. 2, a thick transition occurs between the two semiconductor layers as shown in FIG. A region was formed.

Note 1. The above description merely shows one embodiment of the gas flow rate setting signal generating device according to the present invention, and various modifications and changes may be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a connection diagram showing an embodiment of the gas flow setting signal generator according to the present invention. FIG. 2 is a connection diagram showing a conventional gas flow m setting signal generator. FIG. 3A shows that the gas flow rate setting signal generator according to the present invention is used to generate two semiconductor layers, one of which is InGaAs.
A diagram showing the thickness of the transition region between the two semiconductor layers when the other one is made of InP and is formed by stacking them, as a result of measuring the Auger signal intensity (%) of In. It is. FIG. 3B is a diagram similarly showing the thickness of the transition region between two semiconductor layers when similar semiconductor layers are formed using a conventional gas flow rate setting signal generator. 1... Setting signal generation circuit 2...
...Transmission line 3... Gas flow rate control device 4...
..... Constant voltage DC power supply 5 ..... Variable voltage divider 6 ..... Selection circuit 5.5A15B ..... Setting signal generation circuit M. ......Gas flow rate setting signal S, 818B ......Setting signal Applicant: Nippon Telegraph and Telephone Corporation, IIIFM Figure 3A Figure 3B

Claims (1)

[Claims] In the gas flow rate setting signal generation device having a setting signal generation circuit that generates an electrical setting signal and a transmission line that transmits the setting signal from the setting signal generation circuit to the gas flow rate control device as a gas flow rate setting signal, The setting signal generation circuit includes a plurality of setting signal generators and a selection circuit that selects a plurality of setting signals respectively obtained from the plurality of setting signal generators and sends the selected setting signal to the transmission path. 1. A gas flow rate setting signal generator comprising: