JPH06295882A - Dry etching system - Google Patents

Abstract

PURPOSE:To provide a high operating rate dry etching system having long maintenance period and short maintenance time. CONSTITUTION:The dry etching system comprises two exhaust systems wherein one system is provided with a detachable recessed piping 1513 being cooled by a cooling water circulation piping 1515 in order to deposit reaction products positively. An alarm is delivered when a predetermined deposition film thickness is reached and a main exhaust system is interrupted followed by automatic switching to the other exhaust system. Consequently, maintenance period can be regulated correctly and the maintenance of piping simply requires to replace the detachable piping 1513 with a spare piping thus shortening the maintenance time. Furthermore, etching can be carried out continuously even during maintenance of the piping 1513 thus realizing high operating rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry etching apparatus.

[0002]

2. Description of the Related Art In recent years, in LSI devices which have been increasingly integrated, particles generated in a diffusion manufacturing apparatus have become a problem. Along with the miniaturization of patterns, the size of problematic particles has become smaller.

FIG. 27 shows a conventional dry etching apparatus. Reference numeral 2701 is a lower electrode (cathode), which also serves as a stage for holding a wafer 2702 which is an object to be etched.
Reference numeral 2703 is a temperature setting element, which is composed of a heater and a cooler, and controls the temperature of the lower electrode 2701. 2704 is an upper electrode (anode), which also serves as an etching gas outlet.
Grounded to ground. 2705 is a heater for the upper electrode. A is a vacuum reaction chamber surrounding them, and these are parallel plate type reactive ion etching (RIE).
Configure the device.

In this structure, the wafer 2702 is the lower electrode.
After being set on the 2701, the etching gas is blown from the upper electrode 2704 which also serves as a gas blowing port, and the pressure in the vacuum reaction chamber A is controlled to a predetermined pressure by the operation of a pressure variable valve (not shown) in the exhaust system. A wafer 2702 is etched by applying a high frequency signal, for example, a high frequency signal having a frequency of 13.56 MHz to the lower electrode 2701.

As described above, in the dry etching process, the reactive etching gas is introduced, plasma is generated to generate a reaction product of the material to be etched and the etching gas, and the product is exhausted to the outside of the vacuum reaction chamber A. Is etching in. However, the generated reaction product is also deposited on the inner wall of the vacuum reaction chamber A. When the amount of this deposition increases, it peels off and becomes particles that fall onto the object to be etched. An unetched portion is generated in the dropped portion, resulting in a defective product. Further, the reaction product deposited on the inner wall of the vacuum reaction chamber A and each component arranged inside the vacuum reaction chamber A is exposed to plasma during etching, so that gas is generated from this reaction product. The gas pressure and etching rate fluctuate. Moreover, when the reaction product is deposited on the etching end point signal detection window, the detection signal intensity is attenuated, the detection sensitivity is lowered, and the etching end point detection becomes unstable.

[0006]

As a method of removing the reaction products deposited on the inner wall of the vacuum reaction chamber A and the components arranged inside the vacuum reaction chamber A, which cause particles, the vacuum reaction chamber is used. There is a method of introducing an etchable gas into A, generating plasma, and removing it by etching. In this method, the dry etching device is originally created for the purpose of etching the object to be etched on the stage, and in order to remove the reaction products deposited on the inner wall of the vacuum reaction chamber and each component of the vacuum reaction chamber by etching. , Takes a very long time. Further, the particle removing effect is not so great. For example, it has been reported that 421 particles were reduced to 189 before and after this removal method was implemented (No.
53rd Autumn Meeting of Japan Society of Applied Physics, Fujitsu Limited: “H
In-situ chamber cleaning "16a-SK-7) in Br RIE".

As another method for removing the deposited reaction product, there is a method in which the vacuum reaction chamber A is opened to the atmosphere, mechanical polishing and chemical removal are performed. According to this removal method, the effect of removing the reaction products is great, but it takes a long time to check the atmospheric control-cleaning-vacuum, basic etching characteristics such as etching rate and uniformity of etching rate, and facility control items such as particle check. It costs. Since a cleaning process must be frequently performed in a production site where a large number of products are processed, there is a problem that the facility operation rate is significantly reduced.

Normally, the cleaning cycle of the vacuum reaction chamber is regulated by the number of sheets to be processed and the high-frequency power application cumulative time, but in the actual production site, the film thickness of the object to be etched, the etching conditions, etc. differ depending on the product type. . Therefore, it is very difficult to define the cleaning cycle. Even within the specified range, particles may increase and the product yield may decrease. Further, the cleaning of the exhaust pipe portion cannot be easily performed, and if it is done, the equipment must be stopped for several days at present. .

[0009]

In the dry etching apparatus of the present invention, a stage for holding an object to be etched in a vacuum reaction chamber is controlled to a desired temperature by using a heater or a liquid whose temperature is controlled, and the vacuum reaction chamber is controlled. A temperature control means for controlling the wall, the etching end point signal detection window, and each component provided in the vacuum reaction chamber to a temperature equal to or higher than the evaporation temperature of the reaction product generated by the etching gas and the object to be etched. To do.

Further, in a dry etching apparatus having a vacuum exhaust system composed of a variable pressure valve and a vacuum pump,
An exhaust pipe provided from the exhaust port position to the pressure variable valve position provided on the inner wall of the vacuum reaction chamber, and temperature control means for controlling the pressure variable valve to a temperature equal to or higher than the evaporation temperature of the reaction product generated by the etching gas and the object to be etched are provided. It is characterized by being provided.

The temperature to be controlled is such that the reaction product generated by the etching gas and the object to be etched is heated in a vacuum, and the mass number of the element that is desorbed / vaporized from the reaction product,
In an analyzer for detecting the amount of evaporation, when the temperature of the reaction product is continuously raised, the first detected intensity, the second detected intensity, ... Is characterized in that the temperature is higher than

In addition, in a dry etching apparatus having a vacuum exhaust system consisting of a variable pressure valve and a vacuum pump, a stage for holding an object to be etched in a vacuum reaction chamber in an exhaust pipe from a variable pressure valve position to a vacuum pump,
It has a vacuum reaction chamber inner wall, an etching end point signal detection window, and a detachable concavo-convex shape and a concave piping part that are controlled to a temperature lower than the temperature of each component provided in the vacuum reaction chamber, and is removable. A film thickness detection mechanism for reaction products is installed in a simple pipe section, and when the desired film thickness is exceeded, the signal is AD /
CP of dry etching equipment via DA converter
U, electric power is sent to the display unit, an abnormality is displayed, and the etching process thereafter is stopped. The function to stop the etching is ON / OFF of the high frequency power supply, ON / OF of the gas flow rate control system
F, recognizes ON / OFF signal of gas pressure control system. If any one of these systems is operating, the current etching process is continued, and after the etching is completed, the carrying system for carrying the next object to be etched to the vacuum reaction chamber is stopped. When the signals from the high frequency power source, the gas flow rate control system, and the gas pressure control system are all stopped, the transfer system for transferring the subsequent etching target to the vacuum reaction chamber is stopped, and the pressure variable valve and the detachable pipe First provided between the section
The exhaust cutoff valve, the second exhaust cutoff valve provided between the detachable pipe and the exhaust pump, and the bypass exhaust system provided between the second exhaust cutoff valve and the exhaust pump. Open the third exhaust cutoff valve, and open the fourth exhaust cutoff valve of the bypass exhaust system provided on the pressure variable valve side from the first exhaust cutoff valve between the pressure variable valve and the detachable pipe part. It is characterized in that an exhaust control mechanism is provided.

[0013]

According to this structure, the reaction generation is performed by controlling the temperature of each portion other than the stage for holding the object to be etched so as to be higher than the evaporation temperature of the reaction product generated by the etching gas and the object to be etched. Prevent the accumulation of things. As a result, particles that fall onto the object to be etched and cause product defects can be reduced, and the frequency of cleaning the apparatus can be reduced.

Further, in the vacuum exhaust system, the exhaust pipe between the exhaust port position provided on the inner wall of the vacuum reaction chamber and the pressure variable valve, and the pressure variable valve are provided with a reaction product generated by the etching gas and the object to be etched. By controlling the temperature so that the temperature is equal to or higher than the evaporation temperature of the substance, it is possible to reduce troubles caused by depositing the reaction product.

A detachable pipe section controlled to a temperature lower than the evaporation temperature of the reaction product is provided between the variable pressure valve and the vacuum pump, and the reaction product is forcibly deposited on this pipe section to form a pipe. Prevents dirt and corrosion inside.

Further, since this pipe portion is removable, it is only necessary to replace it with a spare pipe at the time of cleaning, and cleaning can be performed at a later date. Therefore, the facility stop rate due to cleaning can be significantly improved. In addition, since there is a correlation between the deposited film thickness of the detachable pipe section and the deposited film thickness in the vacuum reaction chamber, by providing the deposited film thickness detection section of the reaction product in this pipe section, The frequency of cleaning the reaction chamber can be defined.

Further, when the deposited film thickness of the deposited film thickness detecting portion exceeds the prescribed film thickness, the etching process currently in progress is automatically continued and the next etching process is stopped. In addition, even when processing products with different film thickness, etching conditions, etc. of the object to be etched, by monitoring the deposited film thickness of this piping part, it is possible to prevent a decrease in product yield due to an increase in particles. Becomes

In addition, it has a vacuum exhaust system of another system,
Since this exhaust system is automatically switched, cleaning of the detachable pipe section can be performed without stopping the equipment.
As described above, according to the present invention, the equipment cleaning cycle is extended and the cleaning time is shortened, so that the operation rate of the equipment is dramatically improved.

[0019]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows a dry etching apparatus of the first embodiment.

Reference numeral 1 denotes a temperature setting element for the lower electrode 2, which is composed of a heater, a cooler, etc. and controls the temperature of the lower electrode 2. 3 is a wafer, 4 is an upper electrode, 5 is an upper electrode heater, and 6 is a heater for heating the side wall of the vacuum reaction chamber.

The upper electrode 4 also functions as an etching gas outlet and is grounded. The lower electrode 2 also serves as a stage for holding the wafer 3 to be etched, and a high frequency signal, for example, a high frequency signal having a frequency of 13.56 MHz is applied. It should be noted that the temperature setting element 1 and the heaters 5 and 6 may use a mechanism that circulates temperature-controlled water using a circulator or the like.

The dry etching process using this apparatus is
Taking dry etching of polysilicon as an example
explain. The gas used for etching here is SF₆ ,
CF _Four , HCl, HBr, O₂ Is.

First, the temperature was controlled by the temperature setting element 1.
400nm thick polysilicon is deposited on the lower electrode 2.
The wafer 3 thus carried is transported. In FIG. 1 of this specification, the transport system
Is omitted. Next, the inside of the vacuum reaction chamber A
Vacuum state (7 × 10^-FiveExhausted to about Pa), then
SF from upper electrode 4 which also serves as a gas outlet₆ , CF
_Four , HCl, HBr, O₂ Blow out a mixed gas of. Poly
Silicon etching is performed in multi-steps.
The mixing ratio of the above gases is changed at the step. Each gas is
The flow rate is set using the sflow controller. Also true
The degree of vacuum in the empty reaction chamber A depends on the rotary pump or
A variable pressure valve (orifice
, Butterfly valve, etc.)
It is set to a predetermined pressure for each tap. After that, the lower electrode 2
Apply a high frequency (13.56MHz) to. The output is
It is set for each group. The high frequency generated by the high frequency generator
It is applied to the lower electrode 2 via a coaxial cable. En route
Matching to minimize high frequency reflected wave components
Units are connected. This time, exhaust system, gas introduction system, high
The description of the frequency application system is omitted. With the above system, each step
Dry etching is performed under the conditions set for each group. So
Then, the wafer 3 which has been subjected to the etching is transferred through the above-mentioned transfer system.
It is carried out from the vacuum reaction chamber A to the outside.

The etching conditions at this time are as follows:
Gas flow rate ratio SF ₆ / CF ₄ = 20/20 SCCM, gas pressure 23 Pa, high frequency power 200 W, etching time 1
5 seconds, second step: HCl / HBr / O ₂ = 30/5
0/1 SCCM, gas pressure 20 Pa, high frequency power 350
W, end point detection, third step: HCl / HBr / O ₂ =
10/60/1 SCCM, gas pressure 27 Pa, high frequency power 350 W, etching time 90 seconds. The first step is the removal of the natural oxide film on the upper layer of polysilicon, the second step is the main etching of polysilicon, and the third step is the over-etching, which is performed to leave the underlying oxide film without etching.

At this time, the temperature of the lower electrode 2 is controlled by using the temperature setting element 1. The temperature is determined from the graph of wafer temperature / taper angle shown in FIG. The taper angle referred to here is the angle θ shown in FIG.
Is. The vertical axis of the graph in FIG. 2A is the taper angle of the polysilicon cross section, and the horizontal axis is the wafer temperature. From this graph, the taper angle increases as the wafer temperature decreases. That is, a forward taper shape is formed. This is because the reaction product generated by etching is deposited on the side wall of the polysilicon and serves as a side wall protective film to suppress the lateral etching. However, when the wafer temperature rises, the sidewall protection film does not deposit on the polysilicon sidewall and evaporates. Therefore, the etching progresses in the lateral direction to form an inverse tapered shape. From this, the lower electrode 2 is heated to a temperature at which the taper angle becomes 90 degrees,
Controlled to ± 5 ° C. This means that the evaporation temperature of the reaction product at this degree of vacuum is around 95 ° C. If the temperature of the upper electrode 4 is higher than this temperature,
The reaction product remains in the gas state and does not deposit on the upper electrode. Therefore, the temperature of the upper electrode 4 may be set to 100 ° C. or higher. In this example, the temperature was set to 120 ° C. Further, when the side wall of the vacuum reaction chamber A is heated to 100 ° C. or higher by using the heater 6, the reaction product does not deposit on the side wall.

However, when this method is used, the vacuum reaction chamber A
Although the reaction product does not deposit at all, it may be exhausted in a gas state and deposited on a vacuum pipe or a vacuum pump, which may make maintenance difficult.

Therefore, as shown in FIG. 1, a plurality of heaters are installed as the heater 6 on the outer side wall of the vacuum reaction chamber A, and a temperature gradient as shown in FIG. 3 from the upper electrode 4 side toward the lower electrode side. To provide. Fig. 3 is a schematic diagram of the temperature distribution on the side wall of the vacuum reaction chamber and the state inside the vacuum reaction chamber. There is a temperature gradient from the top of the vacuum reaction chamber A to 120 ℃, 100 ℃, 80 ℃, 60 ℃, 40 ℃. ing. 7 is a reaction product, and 8 is an exhaust port. In this case, 100 is above the wafer 3 installation position.
The temperature is higher than 0 ° C., and as a result, the reaction product 7 does not deposit on the side wall of the vacuum reaction chamber A above the installation position of the wafer 3. The reaction product 7 is the bottom of the vacuum reaction chamber A,
And is deposited only around the exhaust port 8.

As shown in the above examples, by heating the upper electrode to a temperature above the evaporation temperature of the reaction product 7, deposition of the reaction product 7 on the upper electrode 4 can be eliminated, and the vacuum reaction chamber By providing the temperature gradient to A, the deposition site of the reaction product 7 can be controlled. Along with this, the number of particles resulting from the reaction product 7 is drastically reduced as shown in FIG.

The particles were obtained by irradiating the wafer 3 with a laser and measuring the scattering intensity. In FIG. 4, the vertical axis represents the number of particles generated and the horizontal axis represents the number of etching treatments. The solid line shows the result after the above measures, and the broken line shows the result before the measures. In the broken line, the number of particles increases with the number of etching processes, and becomes 400 when 400. The particles were analyzed by EPMA and found to be O, C, Si and Br. Initially, in this state, dry cleaning was performed for the purpose of removing particles on the side wall of the vacuum reaction chamber A. The conditions are SF ₆ / O ₂ = 20/80 SCCM, 107 Pa, 3
00W, 25 minutes. 400 to 150 particles
But it was insufficient [in this regard,
"In situ at HBr RIE" from Fujitsu Limited at the 53rd Academic Meeting of Applied Physics (Autumn 1992)
There was a report of chamber cleaning "16a-SK-7. According to the result, it was said that the number of 421 was reduced to 189".

Therefore, it is necessary to open the vacuum reaction chamber and perform particle removal cleaning by mechanical polishing. However, in the case of this embodiment, the number of particles is all within 50, and it can be seen that cleaning is not necessary even when the number of processed particles is 2,200.

Further, another effect is shown in FIG. The vertical axis represents the etching time and the horizontal axis represents the number of etching treatments.
Here, the etching time is based on the result of the end point detection attached to the apparatus. The solid line shows the result after the above measures, and the broken line shows the result before the measures. Before the countermeasure, there was a tendency that the etching time gradually increased with the number of processed wafers. This is the upper electrode 4
Alternatively, it is considered that the influence is caused by the gas generated from the reaction product 7 deposited on the side wall of the vacuum reaction chamber A. On the other hand, as shown by the solid line in FIG. 5, the etching time hardly changed after the above measures. That is, as shown in FIG. 3, the reaction product 7 does not deposit above the installation position of the wafer 3, but deposits below the installation position of the wafer 3. Even if they are deposited on the bottom of the vacuum reaction chamber A, they are immediately exhausted from the exhaust port 8, so there is almost no effect of gas. As a result, the wafer 3 can be always processed in a stable etching state.

Although the examples of the present specification relate to the dry etching of polysilicon, even in the dry etching of an oxide film, an aluminum alloy, a refractory metal, etc., the reaction products generated by the etching gas and the object to be etched are used. The same effect can be expected by controlling the temperature of the upper electrode or the side wall of the vacuum reaction chamber to a temperature higher than the evaporation temperature.

FIG. 6 shows a dry etching apparatus of the second embodiment. Here, the case of etching the polysilicon film will be described. The lower electrode 601 is temperature controlled to 90 ° C by the heater 603 as a temperature setting element, and the upper electrode 601 is
The heater 605 for heating 604 was turned off, the heater 609 for heating the side wall 607 of the vacuum reaction chamber A was turned off, and etching was performed. Reference numeral 606 is an etching end point signal detection window portion. Reference numeral 608 is an exhaust port.

Particle measurement was performed every 50 etching treatments. Wafer that is the object to be etched 602
Is a polysilicon film 400 on a 6 inch silicon wafer.
nm, then 200 nm of silicon oxide,
After that, a resist mask was formed, and a silicon oxide film having a thickness of 200 nm was etched by an oxide film etching apparatus different from that of this example. Then, a resist mask-removed silicon oxide film mask was used. The etching condition is that the etching gas flow rate ratio is sulfur hexafluoride (SF ₆ ) / chlorine (Cl
₂ ) / Hydrogen bromide (HBr) = 30/30/30 SCC
M, gas pressure 30 Pa, high frequency power 300 W, etching time 2 minutes. Particle measurement for every 50 etched wafers is 600n on a 6-inch silicon wafer.
Using a m-thick thermal oxide film, particles on the wafer before etching were measured by a wafer surface inspection device, and this wafer was provided with a polysilicon film.
After processing 50 wafers, etching was actually performed under the above-mentioned etching conditions, and the number of particles increased by examining the number of particles again with a wafer surface inspection device. The result is shown in FIG. 7. After processing 300 sheets, the number of particles increased rapidly to 855. The particle management standard for equipment is 50 particles or less.

These particles are referred to as EPMA (Electoron).
Elemental analysis by Probe Micro Analyzer) is mainly composed of silicon (Si), fluorine (F) and slightly chlorine (C).
1), bromine (Br) was contained. Next, the vacuum reaction chamber A
When the deposition state of the reaction product inside the vacuum reaction chamber A is confirmed by opening the chamber to the atmosphere, as shown in FIG.
802 and 803 are the upper electrode 604 and the side wall of the vacuum reaction chamber A 60.
7. It was deposited on the etching end point signal detection window 606.

When this reaction product was collected and subjected to elemental analysis by EPMA, it was found to be Si, F type. The result of analysis of this reaction product by TDS (Thermal Desorption Spectroscopy) is shown in FIG. The vertical axis represents the detected intensity (arbitrary unit), and the horizontal axis represents the temperature rise. The detected peak is SiF ₃ with a mass number of 85. From this, it can be said that the reaction product is SiF ₃ . The peak of SiF3 appears at 80 to 90 ° C as the first peak, at 210 to 230 ° C as the second peak, and at 400 to 450 ° C as the third peak.
After analysis, the mass of the sample was reduced to 1/5.

After cleaning the inside of the vacuum reaction chamber A, in the dry etching apparatus of the second embodiment shown in FIG. 6, the heater 605 for heating the upper electrode 604 is set to 100 ° C., and the side wall of the vacuum reaction chamber A is set. Heat 607 to heat 609
FF was performed and etching was performed. The particle measurement results are shown in FIG. After processing 650 sheets, the number of particles exceeded the control standard value and increased to 425 particles. At this time, if the deposition state of the reaction product inside the vacuum reaction chamber A is confirmed, the reaction product 801 of the upper electrode portion shown in FIG. 8 is greatly reduced, and the side wall portion of the vacuum reaction chamber and the etching end point signal detection. Window reaction products 8
The deposits of 02 and 803 were increasing.

After cleaning the inside of the vacuum reaction chamber A again, in the dry etching apparatus of the second embodiment shown in FIG. 6, the heater 605 for heating the upper electrode 604 and the side wall 607 of the vacuum reaction chamber A are heated. 100 ° C with heater 609
And etching was performed. The particle measurement result is shown in FIG. After processing 1,800 particles, the number of particles exceeded the control standard value and increased to 323 particles. At this time, the vacuum reaction chamber A
8A and 8B, the reaction product 801 of the upper electrode portion, the reaction product 802 of the side wall portion of the vacuum reaction chamber 802, and the reaction product of the etching end point signal detection window portion 803 shown in FIG. The amount of deposits was about the same.

From the above, it can be said that the reaction product is deposited in the low temperature portion inside the vacuum reaction chamber A. After cleaning the inside of the vacuum reaction chamber again, the heater 605 for heating the upper electrode 604 and the side wall 607 of the vacuum reaction chamber A in the dry etching apparatus of the second embodiment shown in FIG.
Etching was performed by setting both the heater 609 and the heater 609 at 250 ° C. The particle measurement results are shown in FIG.
After processing 3,250 sheets, particles exceed the control standard value 140
Increased to pieces.

From the analysis results shown in FIG. 9, although not confirmed by an experiment, the upper electrode was heated to a temperature of 450 ° C. or higher.
4. If the side wall 607 of the vacuum reaction chamber A and the etching end point signal detection window portion 606 are heated, it is expected that the amount of reaction products deposited will decrease and the number of particles that exceed the control standard value will increase. That is, the cleaning cycle is extended and the operating rate of the facility is dramatically improved.

FIG. 13 shows a dry etching apparatus of the third embodiment. Here, the polysilicon film was etched under the following conditions. The lower electrode 1301 is temperature controlled to 90 ° C by the heater 1303 as a temperature setting element, and the upper electrode is
Heater 1305 for heating 1304 and side wall of vacuum reaction chamber A 1
The heaters 1309 for heating 307 were both set to 250 ° C. for etching. Reference numeral 1306 is an etching end point signal detection window portion. 1308 is an exhaust port.

The wafer 1302 as the object to be etched is
Polysilicon film 400nm on 6 inch silicon wafer
And then a silicon oxide film of 200 nm is deposited, a resist mask is formed thereafter, the silicon oxide film of 200 nm is etched by an etching device for an oxide film different from that of this embodiment, and then the silicon oxide film from which the resist mask is removed is formed. The one with a membrane mask was used. The etching condition is that the etching gas flow rate ratio is sulfur hexafluoride (SF ₆ ) / chlorine (Cl
₂ ) / Hydrogen bromide (HBr) = 30/30/30 SCC
M, gas pressure 30 Pa, high frequency power 300 W, etching time 2 minutes.

Here, based on the particle measurement result of FIG. 12 of the second embodiment, the cleaning cycle is set to 3,000.
Specified for each sheet, after processing 3,000 sheets, clean the inside of vacuum reaction chamber A, process 3,000 sheets again, then clean the inside of vacuum reaction chamber A, process 3,000 sheets, 8 cycles of this cycle, that is, 24,000 sheets The pressure control of the equipment became impossible after the treatment. Upon investigating the cause, SiF ₃ , which is a reaction product, was deposited on the exhaust pipe 1310 from the exhaust port 1308 to the pressure variable valve 1311 and the pressure variable valve 1311, and the pressure variable valve 1311 was malfunctioning due to that. .

Therefore, as shown in FIG. 13, the exhaust pipe 1
A heater 1312 was installed on 310 and a variable pressure valve 1311 and the temperature was set to 250 ° C. for etching. The variable pressure valve 1311 was operating normally not only after processing 24,000 sheets, but also after processing 39,000 sheets. After processing 39,000 sheets, a problem occurred due to deterioration of the vacuum pump 1313 vacuum exhaust characteristics.

As described above, by installing the heater 1312, it is possible to reduce the deposition amount of the reaction product at the pressure variable valve 1311 and extend the maintenance cycle of the pressure variable valve 1311.

FIG. 14 shows a dry etching apparatus of the fourth embodiment. In the fourth embodiment, the pressure variable valve 141
Flexible piping 1413 with an uneven inner surface is attached to the exhaust piping of 1 and the vacuum pump 1416 with a flange 1414. This flexible piping 1413 is a cooling water circulation piping
Cooled at 1415. Others are the same as those in the third embodiment.

Here, the polysilicon film was etched under the following conditions. The temperature of the lower electrode 1401 is controlled to 90 ° C by the heater 1403 as a temperature setting element, the heater 1405 that heats the upper electrode 1404 is set to 250 ° C, and the heater 1409 that heats the side wall 1407 of the vacuum reaction chamber A is set to 250 ° C.
Set the temperature to ° C, set the exhaust piping 1410 from the exhaust port 1408 to the pressure variable valve 1411 and the heater 1412 that heats the pressure variable valve 1411 to 250 ° C, and set the flexible piping 141.
Etching was performed by setting 3 at 25 ° C. 1406 is an etching end point signal detection window portion.

The wafer 1402 as the object to be etched is
Polysilicon film 400nm on 6 inch silicon wafer
And then a silicon oxide film of 200 nm is deposited, a resist mask is formed thereafter, the silicon oxide film of 200 nm is etched by an etching device for an oxide film different from that of this embodiment, and then the silicon from which the resist mask is removed. The one with an oxide film mask was used. The etching condition is that the etching gas flow rate ratio is sulfur hexafluoride (SF ₆ ) / chlorine (Cl
₂ ) / Hydrogen bromide (HBr) = 30/30/30 SCC
M, gas pressure 30 Pa, high frequency power 300 W, etching time 2 minutes.

Here, based on the particle measurement result of FIG. 12 of the second embodiment, the cleaning cycle is set to 3,000.
It was specified for each sheet, and after the processing of 3,000 sheets, the inside of the vacuum reaction chamber A was cleaned, after the processing of 3,000 sheets again, the inside of the vacuum reaction chamber A was cleaned, and the processing of 3,000 sheets was repeated, and this cycle was repeated. Vacuum pump after processing 60,000 sheets
There was no trouble with the vacuum exhaust system such as 1416, and the equipment was operating normally. After processing 60,000 sheets, the equipment was overhauled. When the flexible pipe 1413 was removed from the portion of the flange 1414, a considerable amount of the reaction product was deposited on the flexible pipe 1413. Almost no deposit was found on the other pipes.

This is because the upper electrode 1404 of each component inside the vacuum reaction chamber A, the side wall 1407 of the vacuum reaction chamber A, and the exhaust port.
Exhaust piping from 1408 to variable pressure valve 1411 1410
Since the variable pressure valve 1411 is heated, the flexible pipe 1413 is cooled by the cooling water circulation pipe 1415, so that the reaction product is deposited only on the flexible pipe 1413. Flexible piping 141
It is considered that the shape of the inner peripheral surface of 3 is more suitable for the concavo-convex shape because the area on which the reaction products are deposited increases.

In general, when the equipment is overhauled, reaction products are accumulated in all exhaust pipes from the vacuum reaction chamber A to the vacuum pump 1416. Therefore, it is necessary to clean all the pipes. Requires. However, in this fourth embodiment, the flexible piping 1413
Only remove and replace with spare flexible tubing 1413. The removed pipe should be cleaned at a later date. Therefore, the overhaul is completed in a very short time, and it is possible to shorten the equipment stoppage time during the overhaul.

FIG. 15 shows a dry etching apparatus of the fifth embodiment. In this fifth embodiment, two exhaust systems are provided. One system is an exhaust system consisting of an exhaust cutoff valve 1518, a concave pipe 1513 attached by a flange 1514, an exhaust cutoff valve 1519, and a vacuum pump 1523. The other system is a bypass exhaust system consisting of exhaust cutoff valve 1521-exhaust cutoff valve 1522-vacuum pump 1523.
It is 1520. The other points are similar to those of the third embodiment. The concave pipe 1513 is cooled by the cooling water circulation pipe 1515, and the windows 1516, 1 made of transparent glass are provided in the concave portion.
517 has been formed. These windows 1516 and 1517 receive the laser light from one window into the recess of the pipe 1513, and receive the laser light from the other window facing it to detect the change in the intensity of the laser light. The film thickness of the object can be detected.
Explain as 2.

Here, the polysilicon film was etched under the following conditions. The temperature of the lower electrode 1501 is controlled to 90 ° C by the heater 1503 as a temperature setting element, the heater 1505 for heating the upper electrode 1504 is set to 250 ° C, and the heater 1509 for heating the side wall 1507 of the vacuum reaction chamber A is set to 250 ° C.
The temperature was set to ℃, the exhaust pipe 1510 from the exhaust port 1508 to the pressure variable valve 1511 and the heater 1512 for heating the pressure variable valve 1511 were set to 250 ° C., and the pipe 1513 was set to 25 ° C. for etching. 1506 is an etching end point signal detection window portion.

The wafer 1502 as the object to be etched is
A polysilicon film having a thickness of 200 nm, 400 nm, and 600 nm is deposited on a 6-inch silicon wafer, then a silicon oxide film having a thickness of 200 nm is deposited, and then a resist mask is formed. A silicon oxide film having a thickness of 200 nm was etched with a resist, and the resist mask was removed thereafter. The etching conditions are that the etching gas flow rate ratio is sulfur hexafluoride (SF ₆ ) / chlorine (Cl ₂ ) / hydrogen bromide (HB).
r) = 30/30/30 SCCM, gas pressure 30 Pa,
High frequency power is 300 W and etching time is 2 minutes.

Here, from the particle measurement result of FIG. 12 of the second embodiment, the cleaning cycle is set to 3,000.
Although it is specified for each sheet, this is effective when processing is performed under the same object to be etched and under the same etching conditions (small-product mass-production). However, in the case of producing a large number of products, there is a problem that it is very difficult to define the cleaning cycle because the film thickness of the object to be etched, etching conditions, etc. are different for each product.

In FIG. 15, the laser light is made incident through a window 1516 made of transparent glass provided in the concave pipe 1513, the laser light is received at the opposite window 1517, and the change in the intensity of the laser light is detected. It is shown in FIG. The vertical axis represents the laser beam detection intensity (arbitrary unit), and the horizontal axis represents the number of processed wafers. In the figure, the thickness of the polysilicon to be etched is 200 nm, 400 nm, and 600 nm, respectively.
It also shows the case of change to. Polysilicon film thickness 400n
In the case of m, the laser beam detection intensity is 0.9 after processing 3,000 sheets.
Decays to 8. For a polysilicon film thickness of 200 nm, approx.
Attenuation to 0.98 after processing 6,000 sheets. Polysilicon film thickness 60
When it is 0 nm, it attenuates to 0.98 after processing about 1,500 sheets.

From the evaluation results shown in FIG. 16, the laser light detection intensity is determined by the cumulative film thickness of the etched polysilicon under the same etching conditions. In consideration of the particle measurement result of FIG. 12 of the second embodiment, the configuration of the operation control system of the dry etching apparatus is shown in FIG. 17 by prescribing that cleaning is performed when the laser light detection intensity is attenuated to 0.98. It will be described based on.

In the operation control system, a device operation unit / display unit 1701 is connected to a CPU 1703 via an interface 1702, and an AD / DA converter 170 is connected to the CPU 1703.
Each analog signal control system is connected via 4. A
The D / DA converter 1704 is provided with a gas flow rate controller 1706, a gas pressure controller 1707, and a wafer transfer system controller 1 via a deposited film thickness detection unit 1712 provided in a concave pipe 1513 and a main controller 1705.
708, high-frequency power supply controller 1709, exhaust system valve controllers 1710, and vacuum pump controller 1711 are connected.

A control system of the dry etching apparatus of this embodiment will be described with reference to the flow charts of FIGS. In # 1 of FIG. 18, the CPU 1703 reads the deposited film thickness from the deposited film thickness detection unit 1712, and in # 2, the CPU 1703 reads the deposited film thickness detection unit 1
Determine whether the deposited film thickness read from 712 does not exceed the specified film thickness. When it is determined in # 2 that the prescribed film thickness is not exceeded, etching is continued in # 3. # 2
If it is determined that the film thickness exceeds the specified film thickness, the error is displayed on the device operation unit / display unit 1701 in # 4. In this embodiment,
Since the deposited film thickness detection unit 1712 is based on the laser light intensity detection, specifically, when the laser light detection intensity is attenuated to 0.98, an abnormality is displayed in # 3. High frequency power supply for # 5
Recognize ON / OFF of 1709. High frequency power supply with # 5 1
When it is determined that 709 is ON, the current etching is continued in # 6. High frequency power supply 1709 is open in # 5
When it is determined to be F, the ON / OFF of the gas flow rate controller 1706 is recognized in # 7. When it is determined that the gas flow rate controller 1706 is ON in # 7, the current etching is continued in # 6. When it is determined that the gas flow rate controller 1706 is OFF in # 7, the gas pressure controller 1707 is turned ON / OF in # 8.
Recognize F. At # 8, the gas pressure controller 1707 turns off.
If it is determined to be N, the current etching is continued in # 6.

At # 8, the gas pressure controller 1707 becomes OF
If it is determined to be F, and if the current etching is continued in # 6, then the etching interruption routine of # 9 is continued. FIG. 19 shows the # 9 etching interruption routine.

As shown in FIG. 19, in the etching interruption routine, if it is determined in # 8 that the gas pressure controller 1707 is OFF, the wafer transfer system 1708 is stopped in # 10. Then, close the exhaust cutoff valve 1518 with # 11,
The exhaust cutoff valve 1519 is closed at # 12, the exhaust cutoff valve 1522 is opened at # 13, the exhaust cutoff valve 1521 is opened at # 14, and exhaust is performed by the bypass exhaust system 1520. When the current etching is continued in # 6, it is determined in # 15 whether the etching in progress is completed, and if the completion of etching is detected in # 15, # 10 is executed.

Normally, the cleaning cycle of the vacuum reaction chamber A is defined by the number of sheets to be processed and the cumulative time for applying high-frequency power. However, in an actual production site, the film thickness of the object to be etched, etching conditions, etc. are different. Different for each. Therefore, particles may increase even within the specified range, and the product yield may decrease. In this example, the reaction product is positively deposited on the portion of the pipe 1513 that is removable and cooled, and when the deposited film thickness at this portion exceeds the specified value, the etching process currently in progress is performed. Is to continue and stop the next etching process. Naturally, there is a correlation between the deposited film thickness in the portion of the pipe 1513 and the deposited film thickness in the vacuum reaction chamber A. However, if the deposited film thickness on the pipe 1513 is monitored, it is possible to prevent a decrease in product yield due to an increase in particles.

After that, cleaning of the vacuum reaction chamber A is carried out. Each part of the vacuum reaction chamber A and the side wall of the vacuum reaction chamber A are cleaned.
Since 1507 is heated, it accumulates less reaction products and is easier to clean.

When cleaning the vacuum reaction chamber A,
A window made of transparent glass on the pipe 1513 in Fig. 15
This can be done in a very short time because all that is required is to remove 1516 and 1517 and replace this window material with a new one.

Even if the number of sheets to be processed increases and the exhaust system piping needs to be overhauled, the reaction product is accumulated only on the piping 1513 from the flange 1514. Just replace with. At the time of replacement, the exhaust cutoff valves 1518 and 1519 are closed, and the vacuum reaction chamber A is exhausted by the bypass exhaust system 1520. Therefore, the replacement can be performed without stopping the etching process.

Next, a sixth embodiment for etching the polysilicon film with the resist mask by using the dry etching apparatus of the second embodiment shown in FIG. 6 will be described. In the sixth embodiment, a heater for heating the upper electrode 604 by controlling the temperature of the lower electrode 601 to 90 ° C. by a heater 603.
Both 605 and the heater 609 for heating the side wall 607 of the vacuum reaction chamber A were set to 250 ° C. for etching.

Particle measurement was carried out every 50 etching treatments. Wafer as etching target 602
Is a polysilicon film 400 on a 6 inch silicon wafer.
nm was deposited and then a resist mask was formed. The etching conditions are that the etching gas flow rate ratio is sulfur hexafluoride (SF ₆ ) / chlorine (Cl ₂ ) / hydrogen bromide (HB).
r) = 30/30/30 SCCM, gas pressure 30 Pa,
High frequency power is 300 W and etching time is 2 minutes.

Particles for every 50 etching treatments were measured by using a 6-inch silicon wafer on which a 600 nm-thick thermal oxide film was formed and measuring the particles on the wafer before etching with a wafer surface inspection apparatus. In addition, after processing 50 wafers with a polysilicon film, this wafer was actually etched under the above etching conditions, and the particles were measured again by the wafer surface inspection device to check the number of increased particles. The result is shown in FIG. After the processing of 2,150 sheets, the particle control standard of 50 was exceeded, and the number of particles rapidly increased to 284.

Using the same equipment, the lower electrode 601 is a heater 603.
A heater 605 for heating the upper electrode 604 and a heater for heating the side wall 607 of the vacuum reaction chamber A by controlling the temperature to 90 ° C. by
FIG. 12 of the second embodiment under the same conditions with 609 set at 250 ° C.
In the particle measurement results shown in (1), the number of particles was over 140, exceeding the particle control standard of 50 after processing 3,250 sheets, and the cleaning cycle was shortened to about 1,000 sheets.

To investigate this difference, E
Element by PMA (Electoron Probe Micro-Analyzer)
When analyzed, the main components are silicon (Si), fluorine (F), charcoal
Elementary (C) contains a small amount of chlorine (Cl) and bromine (Br)
It was The difference from the second embodiment is that carbon is included.
It is that you are. Next, as in the second embodiment, a vacuum reaction is performed.
The reaction product of the room A was collected, and TDS (Thermal Desorpti
on Spectroscopy). The result is shown in Figure 21.
Show. The vertical axis shows the detection intensity (arbitrary unit), and the horizontal axis shows the temperature rise.
It represents. Same as the analysis result shown in FIG. 9 of the second embodiment.
Similarly, SiF of mass number 85₃ Was detected. Shi
Scarecrow, primary peak at 80-90 ° C, secondary peak at 210-230 ° C
No peak is observed, only the third peak at 400-450 ° C
Appears. This is because each part inside the vacuum reaction chamber A
 This is because it was heated to 250 ° C. Analysis results shown in Figure 9
The biggest difference from the fruit is CH at 400-500 ℃₃ (Mass number 1
5), C₂ H₃ (Mass number 27), C₃ H_Five (Mass number 41
 ), C_Four H₇ The hydrocarbon type peak of (mass number 55) is
Is to be detected. In the second embodiment, for etching
The object to be etched is a poly with a silicon oxide film mask.
Silicon, and in this embodiment, a resist mask
It is a resilicon. Therefore, in the case of this embodiment,
Dist is etched and resist component carbon
(C), hydrogen (H ₂ ) Was included in the reaction product
It The deposit of this hydrocarbon reaction product in the vacuum reaction chamber A
Must be heated above 500 ° C to prevent buildup.
Yes.

After cleaning the vacuum reaction chamber A, the heater 605 for heating the upper electrode 604 of the dry etching apparatus shown in FIG. 6 and the heater 6 for heating the side wall 607 of the vacuum reaction chamber A 6
Both 09 were set to 500 ° C. for etching. The particle measurement result is shown in FIG. After processing 4,250 particles, the number of particles exceeded the control standard value and increased to 120 particles. Figure
Compared with the 250 ℃ setting shown in 20, the cleaning cycle was extended by about 2,000 sheets.

Next, a seventh embodiment in which the aluminum film is etched using the dry etching apparatus of the second embodiment shown in FIG. 6 will be described. In this seventh embodiment, the temperature of the lower electrode 601 is controlled to 90 ° C. by the heater 603, the heater 605 for heating the upper electrode 604 and the side wall of the vacuum reaction chamber A.
Etching was performed by setting the heater 609 for heating 607 to 100 ° C. together.

Particle measurement was carried out every 50 etching treatments. Wafer as etching target 602
Used a 700-inch aluminum wafer deposited on a 6-inch silicon wafer. Usually, when etching an aluminum film, a resist mask is used, but this time it was not used for the purpose of removing the hydrocarbon reaction product generated from the resist.

The etching conditions are that the etching gas flow rate ratio is boron trichloride (BCl ₃ ) / chlorine (Cl ₂ ) / nitrogen (N ₂ ) = 25/40/20 SCCM, gas pressure 25 P.
a, high frequency power 350 W, etching time 3 minutes.
The particle measurement for every 50 etching treatments is 6
An inch silicon wafer with a 600 nm-thick thermal oxide film formed on it was used to measure the particles on the wafer before etching with a wafer surface inspection device. This wafer was processed after processing 50 wafers with polysilicon film. The etching was actually performed under the above-mentioned etching conditions, the particles were measured again by the wafer surface inspection device, and the number of increased particles was examined. The result is shown in FIG. The number of particles increased rapidly to 150 after processing 550 sheets. The particle management standard for equipment is 50 particles or less.

These particles are transferred to EPMA (Electoron
Elemental analysis by Probe Micro Analyzer) revealed that the main components were aluminum (Al) and chlorine (Cl). In addition, this reaction product was converted into TDS (Thermal Desorption Spectroscop
The result of analysis by y) is shown in FIG. The vertical axis represents the detected intensity (arbitrary unit), and the horizontal axis represents the temperature rise. The detected peak is SiCl with a mass number of 62. From this, it can be said that the reaction product is SiCl. In addition, SiC
The peak of 1 is the primary peak at 140-160 ℃, 400-45
A secondary peak was detected at 0 ° C.

After cleaning the inside of the vacuum reaction chamber A, the heater 605 for heating the upper electrode 604 of the dry etching apparatus shown in FIG. 6 and the heater 609 for heating the side wall 607 of the vacuum reaction chamber A are both set at 180 ° C. Etching was performed.

FIG. 25 shows the result of particle measurement at this time. After processing 1,250 sheets, the number of particles increased by 175, exceeding the control standard value. After cleaning the inside of the vacuum reaction chamber A again, the upper electrode of the dry etching apparatus shown in FIG.
The heater 605 for heating 604 and the heater 609 for heating the side wall 607 of the vacuum reaction chamber A were both set at 450 ° C. for etching. The particle measurement result at this time is shown in FIG. After processing 3,550 particles, the particles exceed the control standard value
Increased to 214.

Also in the aluminum dry etching apparatus, the constituent elements of the reaction product deposited in the vacuum reaction chamber and the evaporation temperature of these constituent elements are examined, and the upper electrode, the vacuum reaction chamber wall, and the etching end point are heated to a temperature above the evaporation temperature. When the signal detection window is heated, the amount of reaction products deposited is reduced, the cleaning cycle is extended, and the operating rate of the equipment is dramatically improved.

[0079]

As described above, in the dry etching apparatus of the present invention, the stage for holding the object to be etched in the vacuum reaction chamber is controlled to a desired temperature by using a heater or a temperature-controlled liquid, and the vacuum reaction chamber is controlled. The temperature of each part provided in the wall, the etching end point signal detection window, and the vacuum reaction chamber is controlled to be equal to or higher than the evaporation temperature of the reaction product generated by the etching gas and the object to be etched. Further, in a dry etching apparatus having a vacuum exhaust system including a pressure variable valve and a vacuum pump, the exhaust pipe from the exhaust port position provided on the inner wall of the vacuum reaction chamber to the pressure variable valve position and the pressure variable valve are exposed to the etching gas. It is a dry etching apparatus that controls the temperature so that it is equal to or higher than the evaporation temperature of the reaction product generated by the etching product.

The temperature to be controlled is such that the reaction product produced by the etching gas and the object to be etched is heated in a vacuum, and the mass number of the element that is desorbed or evaporated from the reaction product,
In an analyzer for detecting the amount of evaporation, when the temperature of the reaction product is continuously raised, the first detected intensity, the second detected intensity, ... This is a dry etching apparatus that is at a temperature higher than the occurrence of.

In addition, in a dry etching apparatus having a vacuum exhaust system including a pressure variable valve and a vacuum pump, a stage for holding an object to be etched in the vacuum reaction chamber in an exhaust pipe from the pressure variable valve position to the vacuum pump,
It has a vacuum reaction chamber inner wall, an etching end point signal detection window, and a detachable concavo-convex shape and a concave piping part that are controlled to a temperature lower than the temperature of each component provided in the vacuum reaction chamber, and is removable. A film thickness detection mechanism for reaction products is installed in a simple pipe section, and when the desired film thickness is exceeded, the signal is AD /
CP of dry etching equipment via DA converter
U, electric power is sent to the display unit, an abnormality is displayed, and the etching process thereafter is stopped. The function to stop the etching is ON / OFF of the high frequency power supply, ON / OF of the gas flow rate control system
F, recognizes ON / OFF signal of gas pressure control system. If any one of these systems is operating, the current etching process is continued, and after the etching is completed, the carrying system for carrying the next object to be etched to the vacuum reaction chamber is stopped. When the signals from the high frequency power source, the gas flow rate control system, and the gas pressure control system are all stopped, the transfer system for transferring the subsequent etching target to the vacuum reaction chamber is stopped, and the pressure variable valve and the detachable pipe First provided between the section
The exhaust cutoff valve, the second exhaust cutoff valve provided between the detachable pipe section and the exhaust pump, and the bypass exhaust system provided between the second exhaust cutoff valve and the exhaust pump. The third exhaust cutoff valve is opened, and the fourth exhaust cutoff valve of the bypass exhaust system provided on the pressure variable valve side from the first exhaust cutoff valve is opened between the pressure variable valve and the detachable pipe section. It is a dry etching apparatus having an exhaust control mechanism for controlling.

By using the present invention, reaction products deposited in the vacuum reaction chamber of the dry etching apparatus can be prevented. As a result, the reaction product drops on the object to be etched to reduce particles that cause product defects, and the frequency of cleaning the apparatus can be reduced.

Further, in the vacuum exhaust system, the reaction product accumulated on the exhaust pipe between the exhaust port position provided on the inner wall of the vacuum reaction chamber and the pressure variable valve and the pressure variable valve can be prevented, and the reaction product Trouble caused by the accumulation can be reduced.

Further, a detachable pipe portion is provided between the pressure variable valve and the vacuum pump, and by forcibly depositing the reaction product on this pipe portion, the inside of the pipe can be prevented from being contaminated and corroded. Since this pipe portion is removable, it is only necessary to replace it with a spare pipe at the time of cleaning, and cleaning can be performed at a later date. Therefore, the facility stop rate due to the exhaust pipe cleaning can be significantly improved. In addition, since there is a correlation between the deposited film thickness of the detachable pipe section and the deposited film thickness in the vacuum reaction chamber, by providing the deposited film thickness detection section of the reaction product in this pipe section, The frequency of cleaning the reaction chamber can be defined.

When the deposited film thickness of the deposited film thickness detecting portion exceeds the specified film thickness, it is possible to automatically continue the etching process currently in progress and stop the next etching process. In addition, even when processing products with different film thickness, etching conditions, etc. of the object to be etched, by monitoring the deposited film thickness of this piping part, it is possible to prevent a decrease in product yield due to an increase in particles. Becomes Further, since it has a vacuum exhaust system of another system and automatically switches to this exhaust system, it is possible to carry out cleaning of the detachable pipe section without stopping the equipment.

As described above, according to the present invention, the cleaning cycle of the equipment is extended and the cleaning time is shortened, so that the operating rate of the equipment is dramatically improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a dry etching apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a wafer temperature during etching and a taper angle of a polysilicon pattern in an example of the present invention.

FIG. 3 is a temperature distribution diagram of the side wall of the vacuum reaction chamber of the dry etching apparatus in the first embodiment.

FIG. 4 is a relationship diagram between the number of processed wafers and the number of particles generated in the first embodiment.

FIG. 5 is a diagram showing the relationship between the number of processed wafers and the etching time in the first embodiment.

FIG. 6 is a sectional view of a dry etching apparatus according to a second embodiment.

FIG. 7 is a relationship diagram between the number of processed wafers and the number of particles generated in the second embodiment.

FIG. 8 is a state diagram of deposition of reaction products in the dry etching apparatus of the second embodiment.

FIG. 9 is a result diagram of TDS analysis of the reaction product in the second example.

FIG. 10 is a relationship diagram between the number of processed wafers and the number of particles generated in the second embodiment.

FIG. 11 is a diagram showing the relationship between the number of processed wafers and the number of particles generated in the second embodiment.

FIG. 12 is a relationship diagram between the number of processed wafers and the number of particles generated in the second embodiment.

FIG. 13 is a sectional view of a dry etching apparatus according to a third embodiment.

FIG. 14 is a sectional view of a dry etching apparatus according to a fourth embodiment.

FIG. 15 is a sectional view of a dry etching apparatus of a fifth embodiment.

FIG. 16 is a diagram showing the relationship between the number of wafers processed and the laser beam detection intensity in the fifth embodiment.

FIG. 17 is a configuration diagram of an operation control system of a dry etching apparatus in a fifth embodiment.

FIG. 18 is a flowchart of the operation control system of the fifth embodiment.

FIG. 19 is a flowchart of the operation control system of the fifth embodiment.

FIG. 20 is a diagram showing the relationship between the number of wafers processed and the number of particles generated in the sixth embodiment.

FIG. 21 is a result diagram of TDS analysis of the reaction product in the sixth example.

FIG. 22 is a diagram showing the relationship between the number of processed wafers and the number of particles generated in the sixth embodiment.

FIG. 23 is a relationship diagram between the number of processed wafers and the number of particles generated in the sixth embodiment.

FIG. 24 is a result diagram of TDS analysis of a reaction product in the seventh example.

FIG. 25 is a relationship diagram between the number of processed wafers and the number of particles generated in the seventh embodiment.

FIG. 26 is a relationship diagram between the number of processed wafers and the number of particles generated in the seventh embodiment.

FIG. 27 is a cross-sectional view of a conventional dry etching apparatus.

[Explanation of symbols]

 1501 Lower electrode 1502 Wafer 1503 Heater 1504 Upper electrode 1505 Heater 1506 Etching end point signal detection window 1507 Vacuum reaction chamber side wall 1508 Exhaust port 1509 Heater 1510 Pipe 1511 Pressure variable valve 1512 Heater 1513 Pipe 1514 Flange 1515 Cooling water circulation pipe 1516, 1517 Window 1518 , 1519, 1521, 1522 Exhaust cutoff valve 1520 Bypass exhaust system 1523 Vacuum pump

Continuation of front page (72) Inventor Yoji Bito 1-1, Saiwaicho, Takatsuki City, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd.

Claims (19)

[Claims] 1. A stage for holding an object to be etched in a vacuum reaction chamber is controlled to a desired temperature by using a heater or a temperature-adjusted liquid, and the inner wall of the vacuum reaction chamber, a window for detecting an etching end point signal, and a vacuum reaction. A dry etching apparatus provided with temperature control means for controlling the temperature of each component provided in the chamber to an evaporation temperature of a reaction product generated by an etching gas and an object to be etched. 2. A dry etching apparatus having a vacuum exhaust system including a pressure variable valve and a vacuum pump, wherein an exhaust pipe provided from an exhaust port position to a pressure variable valve position provided on the inner wall of a vacuum reaction chamber and a pressure variable valve are etched. A dry etching apparatus provided with temperature control means for controlling the temperature above the evaporation temperature of a reaction product generated by a gas and an object to be etched. 3. An analyzer for detecting a mass number and an evaporation amount of an element desorbed and evaporated from the reaction product by heating a reaction product generated by an etching gas and an object to be etched in a vacuum. When the temperature of the reaction product is continuously raised, the vacuum detection chamber inner wall is heated to a temperature above which the first detected intensity, the second detected intensity, ... The dry etching apparatus according to claim 1, further comprising: a window for detecting an etching end point signal; and temperature control means for controlling each component provided in the vacuum reaction chamber. 4. An analyzer for detecting a mass number and an evaporation amount of an element desorbing / evaporating from the reaction product by raising a temperature of a reaction product generated by an etching gas and an object to be etched in vacuum. When the temperature of the reaction product is continuously raised, the vacuum reaction chamber is heated to a temperature above which the first detection intensity, the second detection intensity, ... The dry etching apparatus according to claim 2, further comprising exhaust pipes provided on a wall from an exhaust port position to a pressure variable valve position, and temperature control means for controlling the pressure variable valve. 5. A dry etching apparatus having a vacuum exhaust system including a variable pressure valve and a vacuum pump, a stage for holding an object to be etched in the vacuum reaction chamber in an exhaust pipe from a position of the variable pressure valve to the vacuum pump, and a vacuum reaction chamber. A dry etching apparatus having a wall, a window for detecting an etching end point signal, and a detachable pipe section controlled to a temperature lower than the temperature of each component provided in a vacuum reaction chamber. 6. The detachable pipe part, the temperature of which is controlled to a low temperature, has a concave and convex shape and a concave shape.
The dry etching apparatus according to 1. 7. The dry etching apparatus according to claim 5 or 6, wherein a detachable pipe portion whose temperature is controlled to a low temperature is provided with a reaction product deposition film thickness detection mechanism. 8. The detection film pressure detected by a deposition film thickness detection mechanism of a reaction product of a detachable pipe part whose temperature is controlled to a low temperature is transmitted to a CPU via an AD / DA converter, and the detection film pressure is desired. When the film thickness is exceeded, an error is displayed on the display, the etching process is stopped, and the function to stop this etching process is to turn on / off the high frequency power supply, turn on / off the gas flow control system, and control the gas pressure. Recognize the ON / OFF signal of the system, and if any one of these is operating, continue the current etching process, and after the end of the etching in progress, vacuum react the next object to be etched. When the transfer system for transferring to the chamber is stopped and all the signals from the high frequency power supply, gas flow rate control system and gas pressure control system are stopped, the transfer system for transferring the subsequent etching target to the vacuum reaction chamber Stop However, after the stop of the transfer system, the first exhaust cutoff valve provided between the pressure variable valve and the detachable pipe portion was closed, and the first exhaust cutoff valve was provided between the detachable pipe portion and the exhaust pump. Second exhaust cutoff valve closed, second
Open the third exhaust cutoff valve of the bypass exhaust system provided between the exhaust cutoff valve and the exhaust pump of the first exhaust cutoff valve from the first exhaust cutoff valve between the pressure variable valve and the detachable pipe part. The fourth of the bypass exhaust system provided to the side
8. The dry etching apparatus according to claim 5, further comprising an exhaust control mechanism for opening the exhaust cutoff valve. 9. When the evaporation element constituting the reaction product is silicon fluoride, 80 ° C. or higher and 90 ° C. or lower, 210 ° C. or higher
The dry process according to claim 1 or 3, wherein the temperature of each part provided in the vacuum reaction chamber inner wall, the etching end point signal detection window, and the vacuum reaction chamber is controlled to a temperature of 230 ° C or lower, 400 ° C or higher and 450 ° C or lower. Etching equipment. 10. When the evaporation element constituting the reaction product is silicon fluoride, 80 ° C. or higher and 90 ° C. or lower, 210 ° C. or higher
3. The temperature control is performed for the exhaust pipe provided from the exhaust port position to the pressure variable valve position and the pressure variable valve provided on the inner wall of the vacuum reaction chamber at a temperature of 230 ° C. or less, 400 ° C. or more and 450 ° C. or less. Alternatively, the dry etching apparatus according to claim 4. 11. When the evaporation element forming the reaction product is aluminum chloride, 140 ° C. or higher and 160 ° C. or lower, 400 ° C. or higher
The dry etching apparatus according to claim 1 or 3, wherein the temperature of each of the components provided in the vacuum reaction chamber inner wall, the etching end point signal detection window, and the vacuum reaction chamber is controlled to a temperature of 450 ° C or lower. 12. When the evaporation element forming the reaction product is aluminum chloride, 140 ° C. or higher and 160 ° C. or lower, 400 ° C. or higher
The dry etching apparatus according to claim 2 or 4, wherein the temperature of the exhaust pipe from the exhaust port position to the pressure variable valve position, which is provided on the inner wall of the vacuum reaction chamber, and the pressure variable valve are controlled at a temperature of 450 ° C or lower. 13. When the evaporating element constituting the reaction product is a hydrocarbon, it is provided at a temperature of 400 ° C. or higher and 500 ° C. or lower on the inner wall of the vacuum reaction chamber, the etching end point signal detection window, and the vacuum reaction chamber. The dry etching apparatus according to claim 1, wherein the temperature of each component is controlled. 14. An exhaust pipe from an exhaust port position provided on the inner wall of the vacuum reaction chamber to a pressure variable valve position at a temperature of 400 ° C. or higher and 500 ° C. or lower when the evaporation element forming the reaction product is a hydrocarbon. The dry etching apparatus according to claim 2 or 4, wherein the temperature of the variable pressure valve is controlled. 15. The dry product according to claim 1, wherein the object to be etched is a silicon compound, and the etching gas is a fluorine-based compound. Etching equipment. 16. The method according to claim 1, wherein the object to be etched is an aluminum compound and the etching gas is a chlorine-based compound.
The dry etching apparatus according to claim 3, claim 4, claim 11, or claim 12. 17. The dry material according to claim 1, wherein the mask material that defines the etching region of the object to be etched is a resist. Etching equipment. 18. A parallel plate type reactive ion etching apparatus including a lower electrode that also serves as a stage for holding an object to be etched and applies a high frequency, an upper electrode that is grounded to a ground, and a vacuum reaction chamber that surrounds them. And
A dry etching apparatus provided with heating means for heating the upper electrode and the vacuum reaction chamber to an evaporation temperature of a reaction product generated by an etching gas and an object to be etched. 19. The dry etching apparatus according to claim 18, further comprising a plurality of heating elements having a temperature gradient from the upper electrode side to the lower electrode.