JP2007208085A - Plasma processor, and flow dividing ratio testing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tester for objectively testing a flow dividing ratio to a process gas flow divider used for a plasma processor. <P>SOLUTION: The plasma processor comprises: a treatment room in which a sample treated by a plasma is installed, a piping system feeding a process gas to the treatment room, a controller controlling the piping system, and a display monitor connected to the controller. The piping system is equipped with a gas feeding source feeding the process gas; a branch branching a gas line from the gas feeding source to plural lines; a flow rate measuring instrument provided at each gas line after branching; and a control valve for controlling a flow rate of the gas line which is provided at each gas line after branching, and is provided at a down stream of the flow rate measuring instrument. The controller performs in all gas lines such a measuring process as to measure a flow rate by opening the control valve of one gas line and closing the control valves of other gas lines to obtain, and to compare a gas flow rate of each gas line. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plasma processing apparatus for processing an object to be processed such as a semiconductor wafer.

Conventionally, in a semiconductor chip manufacturing process, a plasma processing apparatus for converting a reactive gas introduced into a processing chamber into a plasma by electromagnetic waves is widely used in order to perform desired fine processing on an object to be processed such as a silicon wafer or an LCD substrate. Has been.

In a plasma processing apparatus in a semiconductor manufacturing process, in order to perform uniform plasma processing on an object to be processed, the introduced gas is distributed at a uniform concentration over the entire processing surface of the object to be processed, and also over the entire processing surface. It is necessary to exhaust quickly while maintaining a uniform concentration.

Further, in recent years, the outer diameter of a silicon wafer as an object to be processed used for semiconductor manufacture is 200 mm to 300 mm.
The diameter has been increased to mm. As a result, it has become difficult to perform uniform plasma processing over a wide area on a silicon wafer that is an object to be processed. Therefore, it becomes necessary to individually adjust the supply amount of the processing gas to the central portion and the outer peripheral portion of the silicon wafer.

As a method for adjusting the supply amount of processing gas to the center and outer periphery of the silicon wafer, it is implemented by supplying gas to the center and outer periphery of the silicon wafer from gas supply lines that have independent flow control devices. I can do it.

However, supplying gas to a single processing chamber using a gas supply line having independent flow rate control devices not only leads to an increase in the size of semiconductor manufacturing equipment and a rise in equipment, but also maintenance, etc. However, this is not a preferable method.

Therefore, it is desirable to branch from a gas supply line having one flow rate control device to a two-system gas supply line and to control the diversion ratio. Currently, a process gas shunt supply method using a shunt is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2004-5308) and Patent Document 2 (Japanese Patent Laid-Open No. 2005-2005).
-11258) and Patent Document 3 (Japanese Patent Laid-Open No. 2005-56914).

JP 2004-5308 A JP 2005-11258 A JP 2005-56914 A

There are various process gas diverters, but in any type, flow measurement is attached to each line after diversion so that the flow rate of each gas line branched into two is the desired flow rate. The flow rate is controlled based on the value of the pressure sensor or pressure sensor.

In order to ensure the reliability of the objective process gas diversion ratio of the process gas diverter, periodic calibration is indispensable in addition to the initial calibration of the flow meter and pressure sensor. However, the verification method of the process gas shunt itself has not been established yet.

An object of the present invention is to provide a plasma processing apparatus capable of performing an objective verification of a process gas shunt.

A feature of the present invention is that a processing chamber in which a sample to be processed by plasma is placed, a piping system that supplies process gas to the processing chamber, a control device that controls the piping system, and the control device A plasma processing apparatus having a connected display monitor, wherein the piping system is
A gas supply source for supplying a process gas, a branching device for branching a gas line from the gas supply source, a flow rate measuring device provided in each branched gas line, and a branching gas line And a control valve for adjusting the flow rate of the gas line provided downstream of the flow rate measuring device, and the control device opens the control valve of one gas line and closes the control valve of the other gas line. The measurement process for measuring the flow rate is performed in all the gas lines, and the gas flow rate of each gas line is obtained and compared.

ADVANTAGE OF THE INVENTION According to this invention, the test | inspection with respect to the process gas shunt used with a plasma processing apparatus can be performed objectively and simply.

FIG. 1 is a diagram showing a process gas piping system of a plasma etching apparatus to which the present invention is applied.

As shown in FIG. 1, this process gas piping system includes a gas cylinder 1 for supplying a process gas, a third gas line 9-3 for flowing the process gas from the gas cylinder 1, and a mass flow controller 12 for keeping the process gas flow rate constant. And a valve 2 that primarily shuts off the process gas flowing from the gas cylinder 1, a branch passage 10 that branches the third gas line 9-3 into two gas lines, and a gas that is branched into two systems through the branch passage 10. A first gas line 9-1 and a second gas line 9-2 which are two-system gas lines, a first flow rate measuring device 3-1 for measuring a gas flow rate of the first gas line 9-1, The second flow rate measuring device 3-2 for measuring the flow rate of the gas flowing through the two gas lines 9-2 and the first flow rate adjusting valve 4 for adjusting the flow rate at the outlet of the first flow rate measuring device 3-1.
-1, the second flow rate measuring device 3-2, a second flow rate adjusting valve 4-2 that adjusts the flow rate at the outlet, and a control device 11 that is electrically connected to and controls each flow rate measuring device and the control valve; The display monitor 13 connected to the control device 11 and the alarm 16 are configured. Alarm 16
Any device that can warn with sound, light, or the like may be used.

Here, a portion surrounded by a broken line 15 is defined as a process gas diverter. The first gas line 9-1 and the second gas line 9-2 have the same flow path size.

The gas that has passed through the first flow rate control valve 4-1 is introduced into the processing chamber 6 from the first gas introduction part 7-1 attached to the processing chamber lid 5, and is exhausted through the gas exhaust port 8. In addition, the gas that has passed through the second flow rate adjustment valve 4-2 is introduced into the processing chamber 6 from the second gas introduction unit 7-2 attached to the processing chamber lid 5, and is exhausted through the gas exhaust port 8. In the processing chamber 6, a silicon wafer 14 that is an object to be processed is placed.

The process gas shunt verification method of the present invention having the above-described configuration will be described with reference to the flowchart of FIG.

First, the valve control signal V2 is sent from the control device 11, and the second flow rate adjustment valve 4-2 is closed so as to completely shut off the gas. Next, a valve control signal V1 is sent from the control device 11,
The first flow rate regulating valve 4-1 is opened until it is fully opened (S1).

Next, a valve control signal V3 is sent from the control device 11 to open the valve 2, and a gas having a constant flow rate is supplied from the gas cylinder 1 through the mass flow controller 12 (S2).

Next, the flow rate measured by the first flow rate measuring device 3-1 is sent to the control device 11 as a flow rate monitor signal Q1, and the measured flow rate value is displayed on the display monitor 13 (S3).

Next, the supplied gas flow rate remains the same, and the valve control signal V2 is sent from the control device 11.
Is sent, and the second flow rate adjustment valve 4-2 is opened until it is fully opened. Next, a valve control signal V1 is sent from the control device 11, and the first flow rate adjustment valve 4-1 is closed so as to completely shut off the gas (S4).

Next, the flow rate measured by the second flow rate measuring device 3-2 is sent to the control device 11 as a flow rate monitor signal Q2, and the measured flow rate value is displayed on the display monitor 13 (S5).

Next, the flow rate value measured by the first flow rate measuring device 3-1 displayed on the display monitor 13 and the flow rate value of the second flow rate measuring device 3-2 are compared, and the flow rate ratio is verified (S6).

Here, when each compared flow rate value is the same flow rate, the test is passed (S6: YES).
. When the compared flow rates are different (S6: NO), the verification is rejected, and the control device 11 activates the alarm 16 to transmit the failure to surrounding workers (S7).

In the embodiment shown in FIG. 1 above, the branching of the two gas lines is shown, but the present invention can be implemented even with three branches. In that case, only one gas line is fully opened, the other gas lines are fully closed, the flow rate is measured, such that one is opened and two are closed while measuring the gas line, By comparing the measured flow values of the three gas lines, the diversion ratio can be verified.

It is a gas system diagram of the present invention. It is a flowchart which shows the flow rate ratio verification method of a process gas shunt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gas cylinder, 2 ... Valve, 3-1 ... 1st flow measuring device, 3-2 ... 2nd flow measuring device, 4
-1 ... 1st flow control valve, 4-2 ... 2nd flow control valve, 5 ... Processing chamber lid, 6 ... Processing chamber, 7-1 ...
1st gas introduction part, 7-2 ... 2nd gas introduction part, 8 ... Gas exhaust port, 9-1 ... 1st gas line,
9-2 ... second gas line, 9-3 ... third gas line, 10 ... branch path, 11 ... control device,
12 ... Mass flow controller, 13 ... Display monitor, 14 ... Silicon wafer, 16 ... Alarm.

Claims (4)

A processing chamber in which a sample to be processed by plasma is placed; a piping system for supplying process gas to the processing chamber; a control device for controlling the piping system; and a display monitor connected to the control device. A plasma processing apparatus comprising:
The piping system includes a gas supply source for supplying a process gas, a branching device for branching a gas line from the gas supply source, a flow rate measuring device provided in each of the branched gas lines, A control valve for adjusting the flow rate of the gas line provided in each gas line and provided downstream of the flow rate measuring device;
The control device performs the measurement process of measuring the flow rate by opening the control valve of one gas line and closing the control valve of the other gas line in all the gas lines, and adjusting the gas flow rate of each gas line. A plasma processing apparatus characterized by obtaining and comparing. The plasma control apparatus according to claim 1, wherein
An alarm device connected to the control device;
The said control apparatus issues an alarm from the said alarm device, when a flow rate value does not correspond as a result of gas flow rate comparison, The plasma processing apparatus characterized by the above-mentioned. A processing chamber in which a sample to be processed by plasma is placed; a gas supply source for supplying a process gas to the processing chamber; a branching device for branching a gas line from the gas supply source into a plurality; A flow rate meter provided in each gas line, a control valve provided in each gas line after branching and provided in the downstream of the flow rate meter, and the flow rate meter. A shunt ratio test method using a control device for controlling a valve and a plasma processing apparatus having a display monitor connected to the control device,
The measurement process of measuring the flow rate by opening the control valve of one gas line and closing the control valve of the other gas line is performed on all gas lines, and the gas flow rate of each gas line is obtained and compared. ,
As a result of the comparison, if the measured flow rate values match in all the gas lines, the test is passed, and if they do not match, the flow rate is determined to be rejected. In the shunt ratio test method of claim 3,
As a result of the comparison, if the flow rate values do not match, an alarm is issued.

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