JPH0845917A - Plasma treatment device and plasma treatment method - Google Patents

Abstract

PURPOSE:To obtain a device with which a groove and a hole of microscopic dimensions can be etched at high speed in a highly precise manner by a method wherein an exhaust means, with which the gas plasma and the gas generated from the gas plasma are exhausted from a vacuum treatment chamber through a gas exhaust hole at the effective exhaust speed higher than the specific value. CONSTITUTION:The plasma treatment device is provided with plasma discharge mechanisms 2 to 6, a gas introducing hole 9, a means 7 with which the material to be treated is retained on the place other than the ECR position in a vacuum treatment chamber 1, and means 13 and 14 with which gas is introduced from the gas introducing hole 9 into the vacuum treatment chamber 1. Besides, a means 3 with which electromagnetic waves are introduced into a discharge part 4 for the purpose of generating gas plasma 5 by gas, and a means 11, with which the gas plasma 5 and the gas generated by the gas plasma are exhausted from the vacuum treatment chamber 1 through the gas exhaust hole 10 at the effective exhaust speed of 5001/sec or higher, are provided in the plasma treatment device. An exhaust pump, having the efficiency of exhaust speed of 20001/sec or higher, for example, is used as the means 11 with which the vacuum treatment chamber 1 is evacuated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry etching method and a dry etching apparatus suitable for processing fine and deep grooves and holes.

[0002]

2. Description of the Related Art A dry etching technique is widely used for manufacturing a semiconductor integrated circuit (LSI) because fine processing can be performed more easily than a wet etching technique using a chemical solution. When the conventional reactive ion etching (RIE) method is used, the gas pressure during etching is 10 mTorr to 100 mTorr, and the reaction gas flow rate is 10 sccm to 100 sccm. In the RIE method, if the pressure is lower than the lower limit, the discharge becomes unstable, and if it is higher than the upper limit, isotropic etching occurs. In a conventional dry etching apparatus, a pump having an evacuation speed of 1000 l / sec or less is often used, and the reaction gas flow rate is selected within a range in which the gas pressure can be set.

Further, Japanese Patent Publication No. 52-126174 and Solid State Devices and Materials Co., Ltd.
p207, (1990) (Solid State Devices and Ma)
microwave plasma etching (ECR) technology is disclosed in terials P207, (1990). Further, in the Dry Process Symposium p54, (1988), a magnetron discharge type RIE is described as a journal of vacuum.
Science Technology Bee 9 (2), 310 (1
991) (Journal of Vacuum Science Technology B9
(2), 310 (1991)) discloses a dry etching apparatus such as a helicon type RIE. The reaction gas pressure of these dry etching apparatuses is 0.5 mTorr or more,
The gas flow rate is 20 sccm or less. In the case of the ECR etching method, the etching rate is, for example, polycrystalline silicon as the object to be etched and chlorine (C
l ₂ ), gas pressure 0.5 mTorr, gas flow 20
A value of about 300 nm / min is obtained when the value is sccm.

FIG. 16 shows a microwave dry etching apparatus as an example of a conventional dry etching apparatus.
Reference numeral 101 is a microwave generator, 102 is a waveguide, 104 is a reaction gas inlet, 105 is a reaction gas pipe, 106 is a mass flow controller, 107 is an electromagnet for densifying generated plasma, 109 is a silicon wafer
C, 110 is a sample stage, 111 is a chamber, 112 is a high frequency power source, 114 is a vacuum pump, and 117 is an etching chamber. Microwaves generated by the microwave generator 101 are transmitted through the waveguide 102 and the chamber-111.
Is introduced into the chamber and the reaction gas is turned into plasma in the chamber-111. The plasma etches the silicon wafer surface on the sample stage 110. In the dry etching apparatus, one kind of gas is introduced into the chamber 111 using one gas pipe 105 and one mass flow controller 105, and the gas pipe 105 is connected to the chamber-111.
It is directly attached to 111. The gas inlet 10
The area of the opening of No. 4 is about the cross-sectional area of the gas pipe 105. The gas pressure in the chamber 111 is higher as the flow rate of the reaction gas introduced into the chamber is higher, and the vacuum pump 1
The higher the effective pumping speed in the chamber 14 is, the lower it is. When the gas pressure is 1 mtorr or more, several tens of sccm,
A value of several sccm is used in the low gas pressure region of the order of 0.1 mtorr. The effective pumping speed is determined by the pumping speed of the vacuum pump and the conductance of the pumping system, and is 400 l / sec or less in the conventional device.

The pressure in the processing chamber with respect to the flow rate of the introduced gas is expressed by the following equation.

P = (q + Q) / S (1) where P (Torr) is the pressure in the processing chamber (the gas pressure in the plasma discharge section when the pressure varies depending on the location in the processing chamber), and q is the gas introduced. If not, the amount of leak from the device, Q is the introduced gas flow rate (Torr.l / sec), and S is the effective pumping speed (l / sec) of the device. In the normal case, q is 1/1000 or less of Q and can be almost ignored. In the conventional device, for example, the pumping speed (S ₀ ) of the pump
Equipped with a turbo molecular pump of about 1000 l / sec or less, and the exhaust conductance (C) of the processing chamber is 200 l / sec.
sec to 1000 l / sec, the effective pumping speed S0 at this time is the pumping speeds S1 to Sn of the plurality of pumps.
(N is a numerical value indicating the number of pumps) and the exhaust conductance C of the vacuum processing chamber are represented by the following formula: 1 / S0 = (1 / ΣSn) + 1 / C (2) Formula Conventionally, effective exhaust speed 100 to 400 Evacuation of 1 / sec was performed. Therefore, when the gas pressure is set to 0.5 mTorr, the gas flow rate that can be flowed is 4 to 20 scc.
It was m.

On the other hand, as a quantity representing the ease of gas flow in the vacuum processing chamber, there is a gas residence time in the processing chamber, which is expressed by the following equation.

Τ = V / S (= PV / Q) (3) Formula V is the total volume of the vacuum processing chamber. In the conventional device, the effective pumping speed is 100 to 400 l as described above.
/ Sec, the volume of the vacuum processing chamber is about 100 to 300 l, and the gas residence time is 400 msec to 3000 mse.
It was about c.

[0009]

Along with the miniaturization of LSIs, a technique for processing grooves and holes having a size of about 0.3 μm has been required. However, in the conventional dry etching using the RIE method, gas pressure is required. Is high, the directionality of ions incident on the substrate is disturbed due to ion scattering in gas plasma,
It is difficult to process grooves and holes with fine dimensions with high accuracy.

By lowering the reaction gas pressure, it is possible to prevent the scattering of ions in the gas plasma. In order to anisotropically process a groove or hole having the above dimensions, it is necessary to suppress the incident angle of oblique ions incident on the sample to 1 ° or less, and the reaction gas pressure (operating pressure) is 1 mTorr.
Hereafter, it is desirable to set it to 0.5 mTorr or less. However, in order to stably discharge the plasma, 0.0
A pressure of 1 mTorr or higher is required. Examples of the dry etching apparatus having a low reaction gas pressure include the ECR etching apparatus, the magnetron discharge type RIE apparatus and the helicon type RIE apparatus. However, in the conventional dry etching apparatus, when the reaction gas pressure is low, there is a problem that the etching rate becomes low. That is, it is difficult to increase the directionality of etching and increase the etching rate at the same time because there is a relationship of drain off.

Further, the diameter of the Si wafer forming the LSI is becoming larger. For example, in the above ECR etching apparatus, a single wafer type dry etching apparatus for carrying each wafer into a vacuum processing chamber for etching processing is performed. Was used. Using such a device, for example, in order to etch polysilicon having a thickness of 200 nm on a 6-inch wafer, a processing time of about 1 to 2 minutes is required at an etching rate of 200 to 300 nm / min. When a wafer having a diameter of 8 inches is used, the etching rate decreases due to the etching area dependency (so-called loading effect), the processing time increases to 2 to 4 minutes, and the etching processing rate (throughput) decreases. . When the input power of high frequency or microwave is increased to increase the etching rate to increase the throughput, there is a problem that the ion energy increases and the selectivity decreases. By performing parallel processing using a plurality of the above single-wafer dry etching apparatuses, it is possible to improve the throughput without changing the etching conditions, but the apparatus cost becomes enormous.

Further, in the above ECR etching apparatus, since the cross-sectional area of the opening of the gas introduction port is small, the effective evacuation speed is made larger than that of the conventional apparatus to increase the gas flow rate in the etching processing chamber 117. , For example, 1300
When the flow rate is 1 / sec or more, the gas flow velocity when the gas flows into the chamber 111 from the gas introduction port 104 increases to near the sonic velocity, and a shock wave is generated in the flow to make the pressure in the flow uneven. In this state, not only the uniformity of the gas density on the sample but also the nonuniformity and instability of the plasma due to the discharge occur, which causes a problem such as a reduction in the uniformity of the etching rate. Therefore, it is necessary that the flow velocity of the gas is equal to or lower than the speed of sound, and preferably equal to or lower than 1/3 of the speed of sound.

Further, in the structure in which the gas inlet 104 is near the side of the sample stage 110 which is the exhaust port of the etching processing chamber 117, before the gas entering the chamber from the gas inlet spreads throughout the chamber. However, there is a problem that the gas is not efficiently used because it is exhausted from the exhaust port. Further, depending on the shape of the chamber, there is a problem that the gas flow does not sufficiently spread to the center of the etching processing chamber 117.

Further, since only one mass flow controller 106 and one gas pipe are used to flow one kind of gas, the gas flow in the etching processing chamber 117 is uneven, so that the etching uniformity is poor. There was a problem of becoming.

Further, in the above-mentioned conventional apparatus, as the diameter of the wafer becomes larger, the gas flow becomes larger.
There was a problem that it did not spread to the center of 17.

It is an object of the present invention to provide a dry etching method and a dry etching apparatus capable of etching a groove or a hole having a fine dimension with high accuracy and at a high speed.

Another object of the present invention is to provide a dry etching method and a dry etching apparatus having a large throughput.

Another object of the present invention is to provide a dry etching method and a dry etching apparatus having high anisotropy.

Another object of the present invention is to provide a dry etching method and a dry etching apparatus with high selectivity.

Another object of the present invention is 1 mTorr or less,
500 nm / min or more, preferably 1000 nm / m or more at a low gas pressure of 0.5 mTorr or less
It is an object of the present invention to provide a dry etching method for obtaining a high etching rate of in or more.

Another object of the present invention is to provide a dry etching method and a dry etching apparatus with good uniformity.

It is another object of the present invention to provide a dry etching method and a dry etching apparatus in which the reaction product is less likely to be attached to the surface of the wafer or the inner wall of the processing chamber due to redeposition.

[0023]

The above objects are as follows. First, the gas pressure in the vacuum processing chamber is set to 5 mTorr or less, preferably 1 mTorr or less, and the effective pumping speed is 500.
The residence time of the reaction gas is 300 msec at 1 / sec or more.
Hereinafter, this is preferably achieved by setting the residence time of the reaction gas to 100 msec or less at an effective pumping speed of 1300 l / sec or more.

FIG. 33 shows the pumping speed and gas pressure control range of the present invention and their effects. As described above, the gas pressure is a parameter that controls the etching direction (anisotropic), and the exhaust rate is a parameter that controls the etching rate. In conventional etching, the effective pumping speed is about 400
Because of low-speed exhaust of 1 / sec or less, there is a problem of low etching rate even when using a high-density plasma etching device such as microwave etching, and even if the directionality of incident particles is uniform at low gas pressure, the selection ratio with the mask is low. In practice, high anisotropy processing was difficult because of small size.

The main application range of the present invention can be divided into three areas shown in the figure. That is, (1) regardless of the region of gas pressure, a region for the purpose of speeding up the medium etching speed by 1.5 times or more of the conventional one, that is, a region requiring an effective evacuation speed of 800 1 / sec or more, (2) Area for the purpose of speeding up the etching speed by 1.5 times or more as compared with the conventional one, and medium anisotropy as high as 1.5 times or more as compared with the conventional, that is, an effective pumping speed of 500 l / sec or more , A region requiring a gas pressure of 5 mTorr or less, (3) Conventional 2
Area for the purpose of speeding up more than twice and high anisotropy more than twice that of the conventional one, that is, effective pumping speed 1300 l / sec
The above is a region requiring a gas pressure of 1 mTorr or less.

The method (3) is optimal only from the viewpoint of process improvement, but the semiconductor manufacturing process has various processing steps. Therefore, if the cost of the apparatus is taken into consideration, the required performance can be obtained at low cost. Therefore, the application method of (1) or (2) is also possible.

Since the relationship between the gas pressure P, the exhaust speed S and the gas flow rate Q is expressed by P = Q / S according to the above equation (1), the gas flow rate required to satisfy the above means is required. Minimum gas pressure 0.5mTorr, effective pumping speed 800
When it is set to 1 / sec, it becomes 32 sccm. However, in practice, since the gas pressure is finely adjusted, the fluctuation amount is taken into consideration, and it is preferably 40 sccm or more.

Since the discharge becomes unstable when the gas pressure is 0.01 mTorr or less, the lower limit of the gas pressure is 0.0.
It is desirable to exceed 1 mTorr.

In consideration of the size of the apparatus, the effective pumping speed is 100,000 l / se at the maximum effective pumping speed.
c should not be exceeded.

The gas residence time should be 0.1 msec or more in consideration of the volume of the vacuum processing chamber, the upper limit of the exhaust rate, and the reaction time of the etching surface reaction.

Also, the gas flow rate should not exceed 10,000 sccm, taking into consideration the cost of using the gas and gas flow control.

Secondly, the purpose of the preceding paragraph is to widen the area of the gas inlet so that the flow velocity of the introduced gas is 1/3 or less of the speed of sound, and to provide a gas buffer chamber between the gas inlet and the gas pipe. The exhaust port and the sample base are provided in close proximity to each other, and the mounting position of the gas inlet to the sample base and the chamber is separated,
The chamber is provided in the center direction, a plurality of gas pipes and gas inlets through which the gas flow rate is controlled by a mass flow controller are installed symmetrically around the chamber, and a baffle plate for controlling the gas flow is installed in the chamber. Inside, the height / width ratio of the etching chamber is 0.5 or more, the height of the gas inlet is within 1/3 of the upper part of the etching chamber, and an exhaust system is provided. A vacuum buffer chamber is provided between the etching processing chambers, and typically, the pumping speed is set to 2500 l / s.
ec or more, preferably 4000 l / sec or more,
It is effectively achieved by setting the exhaust conductance to 2000 l / sec or more, preferably 3000 l / sec or more and the effective exhaust conductance to 1300 l / sec or more.

Thirdly, the object of the preceding paragraph is achieved by setting the residence time of the reaction gas in the chamber to be 100 msec or less and further batch-processing a large number of large-diameter wafers at the same time using a large vessel. It

Further, the above objects are to provide an exhaust port at the center of the sample table in the large vessel, set the gas flow rate introduced into the vacuum chamber of the large vessel to 100 sccm or more, and make the electrode area of the sample table 5000 cm. ² or more, the total exhaust conductance of the processing chamber and the exhaust pipe is 3300 l or more, and the exhaust speed is 5000 l /
This can be effectively achieved by using an exhaust pump of sec or more and setting an effective exhaust speed of 2000 l / sec or more.

[0035]

In the conventional dry etching apparatus, when the gas pressure is lowered, the etching rate is remarkably reduced, and a practical etching rate cannot be obtained. It is considered that this is because the number of ions in the reaction chamber decreases when the gas pressure is lowered. The present inventors have made various studies in order to reduce the gas pressure and obtain a high etching rate. As a result, it was found that etching occurs when the ions first collide with the object to be etched. That is, it has been found that, if a large number of unreacted ions (reactive gas) exist in the reaction chamber as compared with already reacted ions (reaction product), the etching rate can be increased even if the gas pressure is the same. Therefore, the factors that determine the ratio of unreacted ions and reaction products were further investigated.

FIG. 5 shows the calculation results of the incident ratio R of the reactive gas and all the incident particles (reactive gas + reaction product) to the substrate when the gas flow rate is changed. That is, the incident rate R is given by R = 1 / (1 + 2.735 × 10 ² C ₁ · A · P / (α · Q)) (4). Here, C ₁ is a constant determined by the object to be etched and the etching gas, and has a value in the range of 0.1 to 10. A is the area to be etched, P is the gas pressure, and α is the gas utilization rate. It is a constant determined by the discharge efficiency of the introduced gas in the etching apparatus, the shape of the etching chamber, etc., and has a value in the range of 10 to 100%. . Q
Is the gas flow rate. In FIG. 5, the etching area A is 78.
5 cm ² , gas utilization rate α 42%, gas pressure 0.5 m
It is displayed as Torr. From this result, it can be seen that the ratio of the reactive gas increases with the gas flow rate. On the other hand, FIG. 6 shows the result of calculation of the change in the gas residence time when the gas flow rate is changed, using Equation (3).
As the gas flow rate increases, the gas residence time decreases rapidly.
Therefore, as the gas flow rate increases, the residence time of the reaction product, which inhibits the etching reaction, in the processing chamber decreases and is quickly exhausted to the outside of the processing chamber, so that the etching reaction is accelerated and the etching rate is increased. However, if the gas flow rate is simply increased, the operating pressure (gas pressure) increases as shown in FIG. 17, and as a result, the anisotropy decreases. Regarding the method of increasing the gas flow rate without changing the operating pressure (gas pressure), as shown in FIG. 17, the gas at the gas inlet at the same operating pressure is increased as the effective exhaust rate (gas flow rate inside the etching process) is increased. The flow rate will increase. That is, by increasing the effective pumping speed, the gas flow rate at the same operating pressure can be increased.

FIG. 7 shows the results of the relationship between the ratio of the reactive gas and the total incident particles and the gas residence time obtained by using the equations (3) and (4). The total volume of the vacuum processing chamber is 10
0 l, the etching area A was 78.5 cm ² , and the gas utilization rate α was 42%.

From FIG. 7, the proportion of the reactive gas increases with the decrease of the gas residence time, and the range from 1 sec to 100 msec.
It can be seen that it changes drastically during. Therefore, in order to efficiently perform the etching reaction, when the ratio of the reactive gas is 60% or more of all the particles incident on the wafer, the gas flow rate is 40 sccm or more, preferably 100 sccm or more from FIG. It is understood that the staying time should be 100 msec or less, preferably 50 msec or less.

The volume of the etching chamber is 1000 l
In the following cases, the gas flow rate in the chamber is 1300 l /
The gas residence time can be realized by setting the time to be not less than sec. Moreover, the total opening area of the gas inlet is 150 cm.
By setting it to ² , the gas flow velocity at the gas inlet is set to 1
It was possible to set the ratio to / 3 or less, and it was possible to prevent the gas flow from becoming compressible. Thereby, the shock wave generated in the gas flow can be suppressed, and the instability and nonuniformity of plasma can be suppressed.

As a result of mounting the gas inlet at a position far from the side of the sample stage which is the exhaust port of the etching chamber, the gas flow spreads sufficiently into the chamber, and the gas is efficiently turned into plasma. As a result, the etching processing speed and uniformity are increased. Moreover, since the direction was directed toward the center of the chamber, the gas was allowed to sufficiently flow toward the center of the chamber, which improved the etching rate and uniformity.

By arranging a plurality of gas pipes through which the gas flow is controlled by a mass flow controller to flow the gas with good symmetry, it is possible to prevent the gas flow in the chamber from being biased. As a result, the etching uniformity increased. The installation of the gas inlet also considered the symmetry, so the uniformity of the gas flow was improved. Further, by attaching the baffle plate, it became possible to control the gas flow in the chamber, and in particular, the gas flow could be created at the place where plasma was generated, and the etching rate was increased.

By setting the height / width ratio of the chamber to 0.5 or more, the gas could sufficiently flow toward the center of the chamber. This will be described with reference to FIG. Shown in the figure are the simulation results of how the density of the gas flow in the etching chamber is affected by the height / width ratio of the etching chamber. Increasing the height / width ratio of the etching chamber increases the density of the flow above the wafer, which is the center of the etching chamber.
It can be seen that the uniformity is improved. As described above, in the present invention, the gas can be made to flow efficiently and uniformly to the center of the etching processing chamber, so that the plasma density is increased and the plasma uniformity is improved. As a result, it becomes possible to perform etching with a high etching rate and good uniformity even in a low pressure region.

In the dry etching apparatus, the lower the operating pressure is, the less the frequency of scattering of the ions incident on the wafer from the plasma and the higher the etching anisotropy. According to the present invention, anisotropic etching by low-pressure operation can be performed with good uniformity at a practical etching rate.

By performing dry etching using a large vacuum processing chamber, a large number of samples can be processed at one time, and thus throughput can be improved. When a large vessel is used, it is particularly important to quickly exhaust the reaction product generated by the etching reaction to the outside of the processing chamber. Therefore, high-speed exhaust is necessary.
In the conventional device, for example, the pump exhaust speed is about 1000.
Equipped with a turbo molecular pump of 1 / sec or less, and an exhaust conductance C of 200 l / sec to 1000 l / sec
And was 100 to 400 l / sec. Therefore, 5
When the gas pressure was set to mTorr, the gas flow rate that could be flown was 40 to 200 sccm. According to the present invention, in the large vessel device, the effective pumping speed 1 is achieved by the high-speed pumping pump and the large pumping conductance as described above.
300 l / sec or more, preferably 2000 l / s
It is possible to flow at a gas flow rate of 800 sccm at 5 mTorr and above ec.

FIG. 18 shows the relationship between the effective pumping speed and the gas residence time when the volume of the vacuum processing chamber is changed from 100 l to 10000 l. When the processing chamber volume is 100 l, the effective pumping speed is 700 l / sec or more, and the volume is 50
At 0 l, 3600 l / sec or more, volume: 10000
At l, the gas residence time can be set to 100 msec or less by setting the effective pumping speed to 70,000 l / sec or more. As an example, an effective pumping speed of 70000
To realize 1 / sec, from the above equation (2),
For example, a pump having an exhaust rate of 140,000 l / sec and a vacuum processing chamber having an exhaust conductance of 140,000 l / sec may be used.

By providing an exhaust port at the center of the sample table, the processing gas density can be made uniform at the center and the periphery of the sample table.

[0047]

【Example】

(Embodiment 1) FIG. 1 shows an embodiment of a high speed exhaust microwave plasma etching apparatus according to the present invention. Vacuum processing chamber 1
An etching gas is introduced into the microwave generator 2 to generate a high frequency of 2.45 GHz in the microwave generator 2, which is used as the waveguide 3
And is transported to the discharge part 4 to generate gas plasma 5. A solenoid coil 6 for generating a magnetic field is arranged around the discharge part for high-efficiency discharge, and an electron cyclotron resonance (Electron Cycle) is generated by a magnetic field of 875 Gauss.
otron Resonance: Also called ECR)
Generate high density plasma. The discharge part has a sample table 7, and a wafer 8 placed on the sample table 7 is etched by gas plasma. The processed etching gas is discharged from the gas inlet 9 through the discharge unit 4, the vacuum processing chamber 1 and the exhaust pipe 10 to the outside of the vacuum processing chamber by the exhaust pump 11. At this time, the exhaust speed can be changed by making the conductance valve 12 variable. The processing gas is introduced into the discharge unit 4 through the gas flow rate controller 13, the gas pipe 14, and the gas inlet 9 through the buffer chamber 15 having mesh-shaped small holes. Two or more gas inlets 9 were provided and arranged symmetrically with respect to the central axis of the discharge part. The gas pressure during etching was measured by a gas pressure sensor 23 installed in the plasma discharge part. This makes it possible to determine the gas flow rate, gas pressure, gas exhaust rate, and gas residence time in the plasma discharge unit. The sample stage on which the wafer is installed is equipped with a cooling mechanism 16 for cooling the wafer to 0 ° C. or lower, and an RF bias 17 of 13.56 MHz to 400 KHz can be applied. The vacuum processing chamber is equipped with a heater 18 and can be heated to 50 ° C. or higher.

The exhaust pump has an exhaust speed of 2000 l / s.
Using two turbo ec molecular pumps, total pumping speed 400
It was set to 0 l / sec and arranged symmetrically with respect to the central axis of the discharge part. In addition, the substantial gas exhaust port portion 1 of the vacuum processing chamber
0 was also arranged as a control with respect to the central axis of the wafer. This made it possible to make the gas flow symmetrical with respect to the wafer center while maximizing the exhaust conductance. The total exhaust conductance of the discharge part that serves as a gas passage, the vacuum processing chamber, the exhaust pipe, and the conductance valve is 4000 l.
/ Sec. For this reason, the diameter of the lower part of the discharge part 4 is made larger than that of the upper part, and accordingly, the diameter of the magnetic field coil 6 installed at this part is also made larger than the coil diameter located at the upper part thereof. The wafer position during etching is located below the center of the bottommost coil in the thickness direction so that the exhaust conductance below the discharge part is maximized. At this time, the maximum effective pumping speed is 2000
1 / sec. The total volume of the discharge part, the vacuum processing chamber, and the exhaust pipe is 100 l, and the gas residence time in the vacuum processing chamber is 50 msec according to the above formula (3).

Using this high-speed exhaust microwave plasma etching apparatus, the Si single crystal used for the Si trench was etched. Sample is Si substrate 500n
Thermal oxide film with a thickness of m, a photoresist mask is formed on it, and the oxide film is dry-etched to a diameter of 0.1 μm.
After forming a 1.0 μm hole pattern, the photoresist is removed and a SiO ₂ mask is formed. Cl ₂ is used as the etching gas, and the gas pressure is 0.5 mTo
rr, microwave power 500W, RF bias 2M
The frequency was 20 W at Hz, the wafer temperature was -30 ° C., and the gas flow rate was changed from 2 to 100 sccm. The magnetic field strength distribution was small from the upper part to the lower part of the discharge part, and the position of 875 Gauss satisfying the ECR condition was 40 mm above the wafer. FIG. 2 shows the gas flow rate dependency of the Si etch rate at this time. The etch rate of 80 nm / min at ₂ sccm increased with the Cl ₂ gas flow rate, and reached 1300 nm / min at 100 sccm. FIG. 3 shows the relationship between the gas pressure and the amount of undercut from the Si mask under the same etching conditions. Since the etching shape of Si has a low gas pressure of 0.5 mTorr, a high directionality is obtained, and the undercut amount of the Si deep hole having a depth of 5 μm is 0.03 μm or less, and there is almost no gas flow rate dependency. . FIG. 4 shows an effective pumping speed 2500 according to the present invention.
1 / sec device and conventional effective pumping speed 150 l
The gas pressure dependence of the Si etching rate when using a device of 1 / sec is shown. The etching conditions are the same as those in the result of FIG. In the conventional etching apparatus, the etching rate of Si is greatly reduced as the gas pressure is lowered. This is because the gas residence time is as long as 470 msec, and the gas exhaust flow rate is low, so that the gas flow rate is reduced at a low gas pressure. With the device of the present invention having a high pumping speed,
1) of conventional equipment at low gas pressure of 0.5 mTorr or less
An etching rate of 0 times or more was obtained, and high-speed etching of 1 μm / min or more could be performed at 0.5 mTorr or less. On the other hand, the dependence of the etching rate on the pore size was small, and the rate difference was within 3% in the pore size between 0.1 μm and 1.0 μm. Even if the gas flow rate is changed, S
The etch rate of iO ₂ hardly changed, and the gas flow rate was 10
SiO ₂ used as an etching mask at 0 sccm
The selection ratio (Si / SiO ₂ ) was about 50.

Further, the etching of phosphorus-doped polysilicon gives almost the same results as in FIGS.
_{2 At a} flow rate of 100 sccm and 1500 nm / min, the undercut amount was 0.03 μm or less.

Example 2 SiO ₂ used for contact holes was etched by the high-speed exhaust microwave plasma etching apparatus shown in FIG. Sample is Si
A Si oxide film having a thickness of 2 μm was formed on the substrate by a CVD method, and a photoresist mask was formed thereon. CHF ₃ is used as the etching gas, and the gas pressure is 0.5 mTorr.
r, microwave power 500W, RF bias 800
The gas flow rate was changed from 2 to 100 sccm at 200 W at KHz and a wafer temperature of -30 ° C. 2 sccm
The etch rate of 50 nm / min increases with the flow rate of Cl ₂ gas to 500 nm / m at 100 sccm.
became in. The etching shape of SiO ₂ is 0.5 m
High directionality can be obtained due to the low gas pressure of Torr,
The undercut amount of the SiO ₂ deep hole having a depth of 2 μm is 0.
When it was less than 05 μm, there was almost no gas flow rate dependency.
Furthermore, the dependence of the etching rate on the hole diameter is small and 0.1μ
The velocity difference was within 3% at pore sizes between m and 1.0 μm. Also, the gas flow rate is 2 sccm to 100 sc
The selection ratio between SiO ₂ and photoresist when the cm was increased increased more than twice.

(Embodiment 3) FIG. 8 shows an embodiment of a rapid exhaust reactive ion etching (RIE) apparatus. Since it is a magnetic field application type equipped with a magnetic field coil, discharge is possible even at 1 mTorr or less. An etching gas is introduced into the vacuum processing chamber 1 and discharged at a high frequency of 13.56 MHz to generate a gas plasma 5. The discharge part has a sample table 7, and a wafer 8 placed on the sample table 7 is etched by gas plasma. The processed etching gas is discharged from the gas inlet 9 through the vacuum processing chamber 1 through the exhaust pipe 10 to the outside of the vacuum processing chamber by the exhaust pump 11. At this time, the exhaust speed can be changed by making the conductance valve 12 variable. The processing gas is introduced into the vacuum processing chamber 1 from the gas introduction port 9 through the gas flow rate controller 13 and the gas introduction port 9 through the buffer chamber 15 having mesh-shaped small holes. Two or more gas inlets 9 were provided and arranged symmetrically with respect to the central axis of the discharge part. The sample table on which the wafer is installed is equipped with a cooling mechanism 16 for cooling the wafer to 0 ° C. or lower. The vacuum processing chamber is equipped with a heater 18
It can be heated to 0 ° C or higher.

The exhaust pump has an exhaust speed of 2000 l / s.
Two turbo molecular pumps ec were arranged symmetrically with respect to the central axis of the discharge part. The total exhaust conductance of the discharge part serving as a gas passage, the vacuum processing chamber, the exhaust pipe, and the conductance valve was 4000 l / sec. At this time, the effective pumping speed is 2000 l / sec. Also, the discharge part,
The total volume of the vacuum processing chamber and the exhaust pipe is 100 l, and the gas residence time in the vacuum processing chamber is 50 ms according to the above equation (3).
ec.

The photoresist used for the multilayer resist mask was etched by the high-speed exhaust reactive ion etching apparatus shown in FIG. The sample was coated with a photoresist on a Si substrate to a thickness of 1.5 μm, baked, and then subjected to SO
An intermediate layer such as G (Spin-On-Glass) or titanium silica is formed, and after patterning with a photoresist thereon, the intermediate layer is dry-etched to form a mask for etching the lower-layer photoresist. is there. O ₂ was used as the etching gas, and the gas pressure was 0.5.
mTorr, RF power 500W, wafer temperature -10
The temperature was set to 0 ° C. and the gas flow rate was changed from 2 to 100 sccm. At 2 sccm, the etch rate of 100 nm / min increased with the flow rate of Cl ₂ gas to reach 1000 nm / min at 100 sccm. The etching shape of the resist has a high directionality because of the low gas pressure of 0.5 mTorr, and the undercut amount of the resist having a depth of 1.5 μm is 0.05 μm or less, and there is almost no gas flow rate dependency. . Further, the dependence of the etching rate on the pore size was small, and the rate difference was within 3% in the pore size between 0.1 μm and 1.0 μm.

(Embodiment 4) An embodiment of the present invention is shown in FIG. The microwave generated from the microwave generator 101 passes through the waveguide 102 and is sent to the etching processing chamber 117 in the chamber 111 through the microwave introduction port. After the flow rate of the gas is adjusted by the mass flow controller 106, the gas is sent to the etching processing chamber 117 through the gas pipe 105. The gas spreads into the etching processing chamber 117 through the gas inlet 104 provided after the gas pipe 105.

The flow of the gas entering the etching processing chamber 117 is controlled by the baffle plate 108 so that the density of the central portion of the etching processing chamber 117 becomes uniform. This gas flow is excited by microwaves in the upper part of the wafer 109 and becomes a plasma state. This plasma generates active particles to etch the wafer. At this time, an external magnetic field is applied by the electromagnet 107 to adjust the microwave energy to be efficiently transmitted to the plasma.

A high frequency voltage can be applied to the sample table by a high frequency power source 112. A bias voltage is applied to the wafer 109 by this power source to control the directionality and energy of incident ions. If this sample stage is equipped with a cooling mechanism and a heating mechanism, it is possible to perform etching while controlling the wafer temperature.

The flow of the gas that enters the chamber 111 from the gas inlet 104, becomes a plasma state in the etching processing chamber 117, and is used in the etching reaction on the wafer 109 is the exhaust port viewed from the etching processing chamber 117 together with the reaction products. Then, the gas is exhausted by the vacuum pump 114 through the exhaust buffer chamber 113 through the side of the sample table 110.

When using a vacuum pump with a high pumping speed,
When a plurality of vacuum pumps are used, the vacuum pump 114 is not directly attached to the chamber 111, but is attached to the chamber 111 via the exhaust buffer chamber 113, so that the exhaust gas next to the sample stage, which is the exhaust port as viewed from the etching processing chamber 117, is exhausted. The speed can be made uniform.
As a result, the flow of gas is uniform, which enables etching with good uniformity.

The components for controlling the gas flow of this embodiment include the gas inlet 104, the baffle 108 and the exhaust buffer chamber 113.

The gas inlet 104 was not treated in the conventional apparatus. The gas pipe 105 was directly connected to the chamber 111, and its connection position was not particularly considered. An example of a conventional device is shown in FIG. The gas pipe 105 is directly attached to the chamber 111.

The present invention is characterized in that the gas flow velocity does not exceed 1/3 of the sonic velocity by widening the area of the opening of the gas inlet. In the embodiment shown in FIG. 9, a gas introduction buffer chamber 116 is provided at a portion where the gas pipe 105 is connected to the chamber 111, and a plurality of gas introduction ports 104 are provided on the wall surface of the buffer portion to open the gas introduction port. By increasing the area of the part, the gas flow velocity is suppressed to 1/3 or less of the speed of sound.

The pressure of the gas flowing through the gas pipe 105 through the mass flow controller 106 is about 1 atm, and if the gas is poured directly into the chamber, the flow tends to be disturbed where the gas enters the chamber due to the pressure difference. In this embodiment, since the gas introduction buffer chamber 116 is provided between the gas pipe 105 and the chamber 111, the flow disturbance due to the pressure difference can be suppressed.

Further, in this embodiment, a plurality of gas pipes 105 including the mass flow controller 106 are attached around the chamber in consideration of symmetry to improve the uniformity of gas flow.

When the plasma is generated near the center of the etching processing chamber, the active particles are efficiently incident on the wafer and the uniformity is increased. The flow of gas flowing along the wall surface of the etching processing chamber 117 has a small contribution to etching.
Therefore, in this embodiment, the baffle plate 108 is attached in order to control the flow of the gas flowing through the wall surface of the chamber 111 to the vicinity of the center of the chamber. Since the baffle 108 also has a side effect of deteriorating the flow conductance, it may have an adverse effect if a too large one is attached. In the present embodiment, the sample table 11 is used as the exhaust port of the etching chamber 117 from the gas inlet 104.
The gap between 0 and the chamber 111 is invisible and does not cover the wafer 109.

Further, in this embodiment, the exhaust buffer chamber 113 is provided between the chamber 111 and the vacuum pump 114, which is one of the features for controlling the flow. In order to make the flow uniform, it is desirable that the exhaust system also has good symmetry.
However, it is necessary to connect a high frequency power source 112 for bias application voltage to the sample table 112, or to attach a cooling mechanism for flowing a coolant in order to perform low temperature dry etching for controlling the temperature of the wafer 109. . Therefore, it is difficult to arrange the exhaust system including the vacuum pump with good symmetry. The vacuum buffer 113 attached in the present embodiment has a function of making the exhaust capacity of the vacuum pump 114 uniformly apply to the exhaust portion of the etching processing chamber 117. Further, even when a plurality of vacuum pumps are attached to increase the exhaust capacity, the exhaust buffer chamber 113 has a high effect of making the exhaust of the etching processing chamber 117 uniform.

FIG. 10 is a horizontal sectional view of the chamber 111 of this embodiment including the gas pipe 105. Although four gas pipes 105 are attached here, the number of the gas pipes 105 may be one because there is the gas introduction buffer chamber 116. However, in order to make the flow uniform, it is better to attach multiple wires in consideration of symmetry.

Using the microwave dry etching apparatus having the above-mentioned structure, a hole or groove of 0.3 to 0.5 μm is formed into Si.
It was formed on the substrate surface. As the sample, a resist mask or a pattern formed by a SiO2 mask is used.
Microwave power 400W, pressure 0.5mTorr, gas flow rate 50sccm, RF bias 30W (13.56)
SF ₆ gas was used under the condition of (MHz). As a result, the etching rate was 500 nm / min or more. The side etch amount was 0.05 μm or less, and a good vertical shape could be obtained.

(Embodiment 5) FIG. 11 shows another embodiment of the present invention. In this embodiment, the gas introducing buffer chamber 116 is not formed in a circumferential shape, but the number of isolated gas introducing buffer chambers 116 corresponding to the gas pipe 105 is attached. Compared with the uniformity, the embodiment shown in FIG. 9 is preferable, but the device shown in FIG. 11 has an advantage that the apparatus can be easily manufactured.

There is a method of attaching a plurality of isolated baffle plates 108 instead of having a circular shape. Further, a plurality of circular baffles 108 may be attached at different heights in the chamber 111, or a combination of a circular baffle and an isolated baffle may be used. Can be attached to various parts of the to control the flow of gas. In this way, the buffer chamber 1
By providing No. 16, the uniformity of the etching rate in the 8-inch wafer was improved by more than 2 times as compared with the case where the chamber was not provided, and it could be set to ± 10% or less.

(Embodiment 6) FIG. 12 illustrates another gas piping method as an embodiment of the present invention. In this example, the gas pipe 105 is connected to the chamber 111 at a plurality of portions, but the flow rate of the gas flowing from the cylinder 115 is controlled by only one mass flow controller 106. Since the flow rate is controlled by only one mass flow controller, the flow rate can be accurately controlled and the device structure can be simplified, while the distance of the gas pipe 105 from the mass flow controller 106 to the chamber 111 is changed. Therefore, there is a drawback that the uniformity of the gas flow in the etching processing chamber 117 is somewhat deteriorated. However, by changing the size of the gas inlet buffer chamber 116 depending on the location, changing the opening area and opening ratio of the gas inlet 104 depending on the location, and adjusting the mounting height, the uniformity of the gas flow can be improved. Since it can be adjusted as a system, the deterioration of uniformity is not so problematic in practical use.

As described above, by using the plurality of gas pipes 105, the uniformity of the etching rate in the 8-inch wafer is more than doubled as compared with the case of the single gas pipe,
It was possible to reduce it to ± 10% or less.

(Embodiment 7) FIG. 13 illustrates another gas piping method as an embodiment of the present invention. The present embodiment is characterized in that the gas flow rate from one or more cylinders 115 is controlled by using one or more mass flow controllers 106 for each of the plurality of gas pipes 105 connected to the chamber 111. By adjusting the flow rate of the gas flowing through each mass flow controller 106, the gas flow in the chamber 111 can be made uniform. In addition to using the cylinders of the same gas species to make the flow of the gas uniform in the etching chamber, in addition to using different gas species to mix different gas species in the etching chamber, The method used can also be performed. By adjusting the number and position of the gas pipes for each gas type, and adjusting the gas flow rate flowing through them, it is possible to mix the different types of gas sufficiently uniformly, and even the flow of the mixed gas in the etching chamber. Can be As described above, by using the plurality of gas pipes 105 and the plurality of gas cylinders, the uniformity of the etching rate in the 8-inch wafer is more than doubled as compared with the case of using the single gas pipe and the single gas cylinder. It was possible to reduce it to ± 10% or less.

(Embodiment 8) Another embodiment of the present invention is shown in FIG.
4 shows. In this embodiment, the gas introduction buffer chamber 116 is attached below the microwave introduction window 103, and the wafer 10
The gas introduction port 104 was formed on the upper part of 9. This method has the advantage that the uniformity of the gas flow is improved and the gas flow density in the center of the chamber is increased. However, due to the high gas pressure in the microwave path,
Blocking the progress of microwaves, gas introduction buffer chamber 11
There is also a problem in that discharge may occur within 6.
However, this is performed by adjusting the microwave power or the electromagnet 107, by time-modulating the gas flow rate in order to suppress the pressure rise in the gas inlet buffer chamber 116, or by supplying the microwave in synchronization with the time modulation. It is not a problem in practice because it can be avoided.

(Embodiment 9) FIG. 19 shows an embodiment of a large-sized vessel fast exhaust reactive ion etching (RIE) apparatus according to the present invention. An etching gas is introduced into the vacuum processing chamber 201 and discharged at a high frequency 202 of 13.56 MHz to generate a gas plasma 203. Vacuum processing chamber has a diameter of 120c
m is a cylindrical type having a height of about 40 cm, the electrode is a parallel plate type cathode coupling type, the upper electrode 204 is a ground potential, the lower electrode 205 is a high frequency applying electrode, and the lower electrode is a sample table on which a wafer is placed. It has become. The lower electrode has a diameter of 90 cm, and in order to improve the uniformity of etching, an exhaust port 206 having a diameter of 10 cm that allows the processing gas to be exhausted is also provided in the central portion of the lower electrode, and the central electrode and the peripheral portion of the lower electrode are exhausted to the outside of the vacuum processing chamber. did. The electrode area is about 6300 cm ^2, and six 8-inch wafers 207 were placed and simultaneously etched. The exhaust rate of the processing gas can be changed by making the conductance valve 208 variable. The processing gas passes through a gas flow controller 209, a gas pipe 210, a gas inlet 211, and a buffer chamber 212 having mesh-shaped small holes.
1 is introduced. Two or more gas inlets 211 are provided,
They were arranged symmetrically with respect to the central axis of the discharge part. The sample table on which the wafer is installed has a cooling mechanism 2 for cooling the wafer to 0 ° C. or less.
13 are provided. The vacuum processing chamber is equipped with a heater 214 and can be heated to 50 ° C. or higher.

The exhaust pump has an exhaust speed of 6000 l / s.
Two turbo molecular pumps ec were arranged symmetrically with respect to the central axis of the discharge part. The total exhaust conductance of the discharge part serving as a gas passage, the vacuum processing chamber, the exhaust pipe, and the fully open conductance valve was 12000 l / sec. At this time, the effective pumping speed is 6000 l / sec. Further, the total volume of the vacuum processing chamber and the exhaust pipe is about 500 l, and the gas residence time in the vacuum processing chamber is 83 msec according to the above formula (3).

The Si single crystal was etched by the high-speed exhaust reactive ion etching apparatus shown in FIG.
The sample was a photoresist mask formed on an 8-inch Si substrate, and six sheets were simultaneously placed on the sample table. CF ₄ is used as the etching gas, and the gas pressure is 200 mTorr.
r, RF power 2 kW (power density 0.32 W / cm
² ) The wafer temperature was set to -50 ° C, and the gas residence time was changed by changing the exhaust speed by changing the opening of the conductance valve. At this time, the gas pressure was constant and the gas flow rate was changed. FIG. 20 shows the gas flow rate dependence of the Si etch rate at this time. Si at a gas flow rate of 50 sccm
The etching rate was 100 nm / min, but at a gas flow rate of 900 sccm, the etching rate increased to 800 nm / min. At this time, the undercut amount from the Si mask after etching to a depth of 1 μm was 0.1 μm or less. The selection ratio between Si and photoresist was 4.0. Within-wafer and across-wafer uniformity of etch rate is ± 5
% Or less.

(Embodiment 10) FIG. 21 shows an embodiment of a large-sized vessel high-speed exhaust microwave plasma etching apparatus according to the present invention. In the vacuum processing chamber 201, five microwave discharge parts 216 are installed, and the gas plasma 203 can be independently generated. A total of five 8-inch wafers 207 were placed under each of the five microwave discharge parts on the sample table arranged in the vacuum processing chamber, and simultaneously subjected to etching processing. Gas exhaust ports 206 were provided in the vicinity of five wafer installation parts inside the sample table. The gas plasma introduces an etching gas into the vacuum processing chamber 201 to generate a high frequency of 2.45 GHz in the microwave generator 217, which is guided by the waveguide 218 to the discharge unit 2.
16 and generate. A solenoid coil 219 for generating a magnetic field is arranged around the discharge part for high-efficiency discharge, and an electron cyclotron resonance (Electron Cyclotron Reson) is generated by a magnetic field of 875 Gauss.
ance: (also referred to as ECR) generates high-density plasma. The etching gas passes through the gas inlet 211, the discharge unit 219, the vacuum processing chamber 201, and the exhaust pump 21.
5 is discharged to the outside of the vacuum processing chamber. The exhaust speed can be changed by making the conductance valve 208 variable. The processing gas is a gas flow controller 209.
Through the gas pipe 210, and is introduced into the discharge part 216 from the gas introduction port 211 through the buffer chamber 212 having mesh-shaped small holes. Two or more gas inlets 211 are provided and arranged symmetrically with respect to the central axis of the discharge part. The sample table on which the wafer is installed is equipped with a cooling mechanism 213 for cooling the wafer to 0 ° C. or lower, and 13.56 MHz to 400 KH.
An RF bias 202 of z can be applied. The vacuum processing chamber is equipped with a heater 214 and can be heated to 50 ° C. or higher.

The exhaust pump has an exhaust speed of 20000 l /
Two turbo molecular pumps of sec were arranged symmetrically with respect to the central axis of the discharge part. The total exhaust conductance of the discharge part serving as a gas passage, the vacuum processing chamber, the exhaust pipe, and the fully open conductance valve was set to 40,000 l / sec. This time,
The effective pumping speed is 20000 l / sec. Also,
The total volume of the vacuum processing chamber, discharge section, and exhaust pipe is about 2000 l
The gas residence time in the vacuum processing chamber is 100 msec.
Is.

The single-crystal Si was etched by the large vessel high-speed exhaust microwave plasma etching apparatus shown in FIG. The sample was a photoresist mask formed on an 8-inch Si substrate, and five samples were simultaneously placed on the sample table. CF ₄ was used as the etching gas, the gas pressure was 5 mTorr, the microwave power was 2 KW, the RF bias was 200 W at 2 MHz, and the wafer temperature was −50 ° C. At this time, the Si etch rate is 900 cc gas flow rate.
m was 1.5 μm / min. At this time, 1μ
The undercut amount from the Si mask after etching to a depth of m was 0.1 μm or less. The selection ratio between Si and photoresist was 3.0. The within-wafer and inter-wafer uniformity of the etch rate was ± 5% or less.

(Embodiment 11) Using the high-speed exhaust microwave plasma etching apparatus shown in FIG. 1, patterns having different total areas were formed on an 8-inch wafer and Al etching was performed. The etching condition is Cl ₂ gas pressure 3 mTorr
r, microwave power 500W, RF bias 2MH
Z was 50 W and the wafer temperature was 0 ° C. Wafer diameter is 6
FIG. 22 shows the relationship between the effective evacuation rate (which will be simply referred to as an evacuation rate in the following description of the embodiments) and the etching rate when the inch is changed to 8 inches. The in-wafer etching area ratio is 50%. Constant gas pressure (3 mTorr
r), the gas flow rate (Q sccm) with respect to the exhaust speed (Sl / sec) is Q = 79.05 × S ×
It is 0.003.

Conventional low speed exhaust (about 200 l / sec)
In the case of Al etching of 6 inches, the etching rate was about 0.8 μm / min. Pumping speed is 500 l /
When it is set to sec, the etching speed is about 1.5 times 1.2 μm.
/ Min, which was about 1.8 times to 1.4 μm / min at 800 l / sec, and doubled to 1.6 μm / min at 1300 l / sec. In the case of the 8-inch wafer, a more remarkable change was recognized, and at 800 l / sec, it was 2.4 times that of the conventional method, and at 1300 l / sec, it was about 3 times that of the conventional method.

Therefore, when it is attempted to obtain 1.5 times or more of the conventional etching rate (6 inches, 200 l / sec) with an 8-inch wafer, it is found that at least 800 l / sec or more is required, and it is more than twice. It was found that at least 1300 l / sec or more was required to obtain the above.

The area dependence of the etching rate is almost the same in other materials such as Si in addition to Al.
In order to obtain an etching rate of 1.5 times or more with an inch wafer, an evacuation rate of 800 l / sec or more was required. Similarly, when the etching conditions such as gas pressure, microwave power, sample temperature, and bias are different, in order to obtain 1.5 times or more of the conventional etching rate with an 8-inch wafer, an evacuation rate of 800 l / sec or more is required. Was needed.

(Embodiment 12) The distance (E) between the ECR surface (the surface where the magnetic field becomes 875 G in the plasma) and the wafer was measured by the high-speed exhaust microwave plasma etching apparatus shown in FIG.
The Si etching was performed by changing the CR surface distance).
The etching conditions are Cl ₂ gas pressure 0.5 mTorr, microwave power 500 W, and RF bias 2 MHz at 2 MHz.
The wafer temperature was 0 W and -30 ° C. FIG. 23 shows the relationship between the ECR surface distance and the etch rate when the exhaust rate is changed. ECR at conventional pumping speed (200 l / sec)
When the surface distance is increased from 0 to 150 mm, the etching speed is 3
It decreased from 00 to 100 nm / min. On the other hand, 50
ECR in etching by high-speed exhaust of 0 l / sec
Even if the surface distance is as long as 150 mm, the etching speed is 300 n
m / min is obtained, and 1000 is obtained when the distance is further reduced.
nm / min or more. That is, even if the ECR surface distance is increased to some extent by high-speed exhaust etching,
It was found that an etching speed equal to or higher than that when the surfaces were brought close to each other was obtained.

A problem when the ECR surfaces are brought close to each other is that the plasma dissociation efficiency is high in the ECR region.
The reaction product generated from the wafer is redissolved and redeposited on the wafer surface. This reduction may lead to deterioration of etching shape and surface contamination.
Further, if the ECR surface distance is reduced, the etching uniformity may decrease. From the surface analysis, when the adsorption amount of the reaction product on the wafer was examined, it was found that the adsorption amount increased as the ECR surface distance decreased when the evacuation rate was 500 l / sec, as shown in FIG. When the exhaust rate is low (200 l / sec), the exhaust rate of the reaction product is slow, and the amount of adsorption to the wafer is large even if the ECR surface distance is separated to some extent and re-dissociation is small. Therefore, in order to perform low-contamination and high-speed etching with less adsorption of reaction products, it is preferable to increase the ECR surface distance to some extent and to perform high-speed exhaust. From the results shown in FIG. 24, it was found that it is appropriate to use an evacuation speed of 500 l / sec or more with an ECR surface distance of 40 mm or more.

(Embodiment 13) The high speed exhaust microwave plasma etching apparatus shown in FIG.
Al was etched at a gas pressure of rr. The etching conditions were Cl ₂ gas pressure of 5 mTorr, microwave power of 500 W, RF bias of 20 MHz at 2 MHz, and wafer temperature of 0 ° C. FIG. 25 shows the relationship between the exhaust rate and the Al etch rate. The gas flow rate is the gas pressure multiplied by the exhaust rate. At 500 l / sec or more, the etching rate greatly increases. On the other hand, FIG. 26 shows the exhaust speed dependency of the undercut amount. Since the gas pressure is as high as 5 mTorr, undercut is likely to occur.
At 1 / sec or more, the increasing tendency was large. The reason why the amount of undercut is small when the exhaust speed is 1300 l / sec or less is that the reaction product stays for a long time and is deposited on the pattern side wall to prevent side surface etching. Therefore, in the case where the undercut can be suppressed only by using the side wall deposition and the high etching rate is required, in order to suppress the undercut amount to 0.1 μm or less at a high etching rate of 1000 nm / min or more, , 500 l / sec was suitable. Further, a similar etching tendency is obtained at a pressure of 1 to 10 mTorr, a high etching rate of 1000 nm / min or more, and an exhaust rate of 5 which satisfies an undercut amount of 0.1 μm or less.
It was between 00 l / sec and 1300 l / sec.
It should be noted that the gas residence time is 300 at the time of 500 l / sec.
It was msec.

Example 14 Al was etched using BCl ₃ gas by the high speed exhaust microwave plasma etching apparatus shown in FIG. The etching conditions are BCl ₃
Gas pressure 4mTorr, microwave power 500W, R
The F bias was 20 W at 2 MHz and the wafer temperature was 20 ° C. FIG. 27 shows the gas pressure dependency of the Al undercut amount.
Shown in The pumping speed was 800 l / sec. Undercut amount decreases significantly below 5 mTorr, 0.1
It became less than μm. Compared to etching with Cl ₂ ,
BCl ₃ reduces undercut at higher gas pressures. The reason for this is that BCl ₃ has the effect of depositing on the pattern sidewall and protecting the sidewall. On the other hand, A
FIG. 28 shows the exhaust rate dependency of the microloading of the etch rate (pattern size dependency: here 0.2 μm; the ratio of etch rates in groove patterns of a and 10 μm; b; a / b). The microloading decreased with an increase in the exhaust speed, and became more than 0.9, which is suitable for practical use, at 800 l / sec or more. The reason why the microloading decreases with the increase of the exhaust speed is that the etching reaction particles are sufficiently supplied also into the small groove due to the increase of the exhaust speed. Therefore, in order to perform undercut and micro-loading controlled etching in Al etching using BCl ₃ , the gas pressure is 5 mTorr.
It was found that a pumping speed of 800 l / sec or more is preferable at r or less. Microrodig is related to the amount of over-etching required to etch the inside of a small groove to the end. In this case, if the microloading is 0.9 or more, there is no practical problem, so the pumping speed is set higher than necessary. do not have to.

Example 15 Al was etched by the high speed exhaust microwave plasma etching apparatus shown in FIG. 1 and the reactive ion etching apparatus shown in FIG. The etching condition is Cl _{2 in the} microwave etching device.
Gas, microwave power 500W, RF bias 2M
The frequency was 20 W in Hz, the wafer temperature was 10 ° C., the RF power was 500 W in reactive ion etching, the Cl ₂ gas was used, and the wafer temperature was 10 ° C. FIG. 30 shows the relationship between the Al etch rate and the gas pressure. The pumping speed was 500 l / sec. Since the microwave etching can be performed at a low gas pressure, the undercut becomes 0.1 μm or less at 4 mTorr and the etching rate is 1000 nm /
It was min. The reactive ion etching cannot be performed at a low gas pressure, the undercut is 0.2 μm at 10 mTorr, and the etching rate is 300 nm / m.
It was in. That is, compared with reactive ion etching, microwave etching has a low gas pressure, has a small undercut, and enables high-speed etching. On the other hand, A
FIG. 31 shows the relationship between the 1 etch rate and the exhaust rate. The gas pressure is 4 mTorr. When the pumping speed is increased, A
l The etch rate is significantly increased in microwave etching than in reactive ion etching. This is because microwave etching has a higher surface reaction rate than reactive ion etching and is, so to speak, a rate-determining state of the supply of etching reaction particles. This is because In particular, the etching rate tended to be saturated at 500 l / sec or more. On the other hand, in the reactive ion etching, the surface reaction rate is small and the reaction rate is controlled, and therefore the increase in the etching rate is small even if the supply of the etching reaction particles is increased by increasing the exhaust rate. Therefore, in order to prevent undercut at a low gas pressure using microwave plasma etching and to increase the etching rate by high-speed exhaust, the gas pressure is set to 4 mTorr or less and 500 l / se.
A pumping speed of c or higher is suitable. The undercut becomes smaller as the gas pressure is lowered, but the Al etch rate is greatly reduced at 0.5 mTorr or less and is 300 nm /
It is less than min, which is not suitable for practical use.

Example 16 Al was etched by the high speed exhaust microwave plasma etching apparatus shown in FIG. 1 and the reactive ion etching apparatus shown in FIG. The etching condition is Cl _{2 in the} microwave etching device.
Gas pressure 4mTorr, microwave power 500W, RF
The bias was 20 W at 2 MHz, the wafer temperature was 10 ° C., and the RF power was 500 W in reactive ion etching.
The Cl ₂ gas pressure was 10 mTorr and the wafer temperature was 10 ° C. FIG. 32 shows the relationship between the Al etch rate and the gas residence time. Here, the gas flow rate was variable. The Al etching rate tended to increase with any etching method due to the decrease in the residence time, but the microwave etching showed a marked increase. The Al etching rate was 1000 nm / min at a residence time of 300 msec. Therefore, when the undercut is 0.1 μm or less, the etching rate is 1000 nm / min.
In order to obtain the above, it is necessary to set the gas residence time to 300 msec or less at a gas pressure of 4 mTorr or less.

[0091]

According to the present invention, the gas flow rate can be increased to 40 sccm or more under a high vacuum of 1 mTorr or less, and the gas residence time can be 100 msec or less, so that undercut can be prevented under a high vacuum and a large gas flow rate can be achieved. Has the effect of achieving a high etching rate and increasing the etching rate ratio (selection ratio) between the material to be etched and other materials. As a result, high aspect ratio (ratio of pattern width / etching depth) etching of Si trenches, contact holes, etc., which requires very high directionality, can be processed at high speed and with high precision.

Even under a gas pressure of 1 mTorr or more, undercut can be prevented to some extent, and the etching rate and etching selectivity can be improved.

Further, since the redeposition of reaction products is small, it is possible to reduce the contamination of wafers and devices, the abnormal etching shape, etc.

The effects of the present invention are not limited to the above-described etching apparatus and etching material, but may be, for example, magnetron type RIE.
And other devices such as helicon resonance type RIE, and aluminum, tungsten, tungsten silicide, copper, G
Similar effects are obtained with other materials such as aAs and Si nitride film.

By using a large vessel,
For example, a large number of 8-inch or larger wafers can be simultaneously etched, and the etching speed thereof can be made about the same as the conventional one, so that the throughput of dry etching can be improved and the cost of semiconductor products can be reduced.

The large-diameter wafer batch processing in the large-sized vessel and the high-speed evacuation processing apparatus according to the present invention has a great effect of increasing the throughput in the processes other than the dry etching. For example, a plasma CVD device, a sputtering device, an ion milling device, a plasma doping device, etc. are examples. In any of these devices, if the vacuum processing chamber becomes large, the amount of residual gas in the processing chamber will increase, causing problems such as film quality deterioration due to residual gas mixing into the formed film, but high-speed exhaust can reduce such effects. A good quality thin film can be formed. Furthermore, the time required for making the residual gas amount equal to or less than the value required for film formation can be shortened by high-speed exhaust, and the process throughput can be improved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a high-vacuum, high-speed evacuation type microwave plasma etching apparatus according to the present invention.

FIG. 2 is a diagram showing a relationship between a gas flow rate and an etching rate in Si etching using a high-vacuum high-speed exhaust type microwave plasma etching apparatus according to the present invention.

FIG. 3 is a diagram showing a relationship between a gas pressure and an undercut amount in Si etching using a high-vacuum rapid-exhaust type microwave plasma etching apparatus according to the present invention.

FIG. 4 is a diagram showing a relationship between a gas pressure and an etching rate in Si etching using a high-vacuum rapid-exhaust type microwave plasma etching apparatus according to the present invention.

FIG. 5 is a diagram showing the calculation results of the incident ratios of the reactive gas and the reaction product to the substrate when the gas flow rate is changed.

FIG. 6 is a diagram showing a calculation result of a gas residence time when a gas flow rate is changed.

FIG. 7 is a diagram showing the calculation results of the incident ratios of the reactive gas and the reaction product on the substrate when the gas residence time is changed.

FIG. 8 is a schematic cross-sectional view of a high-vacuum rapid-evacuation type reactive ion etching (RIE) apparatus according to the present invention.

FIG. 9 is a schematic sectional view of a dry etching apparatus according to the present invention.

FIG. 10 is a partial plan view of the dry etching apparatus according to the present invention.

FIG. 11 is a partial plan view of the dry etching apparatus according to the present invention.

FIG. 12 is a plan view showing a configuration of a gas pipe of the dry etching apparatus according to the present invention.

FIG. 13 is a plan view showing a configuration of a gas pipe of the dry etching apparatus according to the present invention.

FIG. 14 is a schematic sectional view of a dry etching apparatus according to the present invention.

FIG. 15 is a result of simulating the relationship between the height-width ratio of the etching processing chamber and the gas flow density in the etching processing chamber.

FIG. 16 is a schematic sectional view of a conventional dry etching apparatus.

FIG. 17 is a diagram showing the relationship between gas pressure and gas flow rate for different execution exhaust speeds.

FIG. 18 is a diagram showing the relationship between the effective pumping speed and the gas residence time, with the volume of the vacuum processing chamber as a parameter.

FIG. 19 is a schematic view of a large-sized vessel rapid evacuation reactive ion etching (RIE) apparatus according to the present invention.

FIG. 20 is a diagram showing a relationship between a gas flow rate and an etching rate in Si etching using a high-vacuum high-speed exhaust type microwave plasma etching apparatus.

FIG. 21 is a schematic view of a large-sized vessel high-speed exhaust microwave plasma etching apparatus according to the present invention.

FIG. 22 is a graph of Al etch rate and effective pumping rate according to the present invention.

FIG. 23: Si etch rate and wafer-EC according to the present invention
It is a graph of R surface distance.

FIG. 24 is a graph of the reaction product on the wafer surface and the wafer-ECR surface distance according to the present invention.

FIG. 25 is a graph of Al etch rate and effective pumping rate according to the present invention.

FIG. 26 is a graph of Al undercut amount and effective pumping speed according to the present invention.

FIG. 27 is a graph of Al undercut amount and gas pressure according to the present invention.

FIG. 28 is a graph of Al etching depth ratio (depending on pattern size) and effective pumping speed according to the present invention.

FIG. 29 is a schematic view of a rapid exhaust reactive ion etching (RIE) apparatus according to the present invention.

FIG. 30 is a graph of Al etch rate and gas pressure according to the present invention.

FIG. 31 is a graph of Al etch rate and effective pumping rate according to the present invention.

FIG. 32 is a graph of Al etch rate and gas residence time according to the present invention.

FIG. 33 is a diagram showing a range of a process gas pressure and an effective evacuation rate to which the effect of the present invention is applied.

[Explanation of symbols]

1 ... Vacuum processing chamber, 2 ... Microwave generator, 3 ... Waveguide,
4 ... Discharge part, 5 ... Gas plasma, 6 ... Solenoid coil, 7 ... Sample stage, 8 ... Wafer, 9 ... Gas inlet, 10 ...
Exhaust pipe, 11 ... Exhaust pump, 12 ... Conductance valve, 13 ... Gas flow controller, 14 ... Gas pipe, 1
5 ... Buffer chamber, 16 ... Cooling mechanism, 17 ... RF bias, 18 ... Heater, 19 ... Butterfly valve, 20 ... Gas flow, 21 ... Microwave introduction window, 22 ... Upper electrode, 23 ... Gas pressure sensor 101 ... Micro Wave generator, 102 ... Waveguide, 103 ...
Microwave introduction window, 104 ... Gas introduction port, 105 ... Gas pipe, 106 ... Mass flow controller, 107 ... Electromagnet, 108 ... Baffle plate, 109 ... Wafer, 110 ... Sample stage, 111 ... Chamber, 112 ... High frequency power supply, 113
... Exhaust buffer chamber, 114 ... Vacuum pump, 115 ... Gas cylinder, 116 ... Gas introduction buffer chamber, 117 ... Etching processing chamber 201 ... Vacuum processing chamber, 202 ... High frequency, 203 ... Gas plasma, 204 ... Upper electrode, 205 ... Lower electrode , 206
... Gas exhaust port, 207 ... 8-inch wafer, 208 ... Conductance valve, 209 ... Gas flow rate controller, 2
10 ... Gas piping, 211 ... Gas inlet, 212 ... Buffer chamber, 213 ... Cooling mechanism, 214 ... Heater, 215 ... Exhaust pump, 216 ... Discharge part, 217 ... Microwave generator, RF bias, 218 ... Waveguide 219 ... Solenoid coil, 220 ... Gas flow.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takao Kumihashi, Inventor Takao Kumihashi 1-280, Higashi Koikekubo, Kokubunji, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Inventor Junichi Kobayashi 4-6, Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. (72) Kento Usui, Kenjicho, Tsuchiura City, Ibaraki Prefecture, 502, Hiritsu Seisakusho Co., Ltd. (72) Inventor, Nobuyuki Mise, 502, Jinmachicho, Tsuchiura City, Ibaraki, Hirate Seisakusho Co., Ltd.

Claims (74)

[Claims] 1. A mechanism for plasma discharge, a gas inlet, a gas outlet, a means for holding an object to be processed at a position other than the ECR position in the vacuum processing chamber, and a gas being introduced into the vacuum processing chamber from the gas inlet. Means for introducing an electromagnetic wave in order to generate a gas plasma in the discharge part by the gas, the gas plasma and the gas generated thereby from the vacuum processing chamber through the gas exhaust port, and an effective evacuation speed of 500 l.
A plasma processing apparatus for processing an object to be processed, which has a means for exhausting the gas at a rate of not less than / sec. 2. The plasma processing apparatus according to claim 1, wherein the electromagnetic wave introducing unit is a microwave introducing unit. 3. The means for introducing the etching gas comprises:
An etching gas pipe, a tip gas introduction port of the etching gas pipe, a flow rate regulator of the etching gas, and means for controlling a flow rate when the etching gas is introduced into the vacuum processing chamber. The plasma processing apparatus of claim 1, wherein the plasma processing apparatus is a plasma processing apparatus. 4. The plasma processing apparatus according to claim 1, wherein the means for controlling the flow velocity is a buffer portion provided at the gas inlet. 5. The plasma processing apparatus according to claim 1, wherein the gas inlet has a plurality of holes. 6. The etching gas pipe is plural,
The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is arranged substantially symmetrically with respect to a central axis of the vacuum processing chamber. 7. The gas introduction port is arranged substantially toward the central axis of the vacuum processing chamber.
The plasma processing apparatus according to. 8. The plasma processing apparatus according to claim 1, wherein the means for exhausting the inside of the vacuum processing chamber is an exhaust pump having an exhaust speed of 2000 l / sec or more. 9. The plasma processing apparatus according to claim 1, wherein the exhaust pump is a turbo molecular pump. 10. The plasma processing apparatus according to claim 1, wherein the means for changing the effective pumping speed by changing the pumping conductance is a conductance valve provided in a pumping section. 11. The plasma processing apparatus according to claim 1, wherein the exhaust means has a variable control valve that changes the exhaust speed of gas. 12. An object to be processed is installed in a vacuum processing chamber, a gas is introduced into the vacuum processing chamber, the gas is plasma-discharged, the object to be processed is treated with the gas plasma, and a total effective exhaust rate of the gas is obtained. A plasma processing method, characterized in that the gas is exhausted by an exhaust means of 800 l / sec or more. 13. The plasma processing method according to claim 12, wherein the effective pumping speed is changed during the pumping. 14. The above-mentioned processing is at least 15 nm / mi.
13. The plasma processing method according to claim 12, wherein the gas is exhausted at an effective exhaust speed of 500 l / sec or more and the gas residence time in the processing chamber is set to 300 msec or less in the process of performing etching at an etching rate of n or more. 15. A gas pressure of the processing chamber is 5 m for supplying the gas.
13. The method according to claim 12, wherein the operation is performed at less than Torr.
The plasma processing method described in 1. 16. The gas pressure in the processing chamber is 1 when the gas is supplied.
The method according to claim 1, wherein the operation is performed at mTorr or less.
2. The plasma processing method described in 2. 17. The plasma processing method according to claim 12, wherein the gas exhaust is performed for a gas residence time in the processing chamber of 100 msec or less. 18. The gas introduction is performed at a gas flow velocity in the processing chamber of 1/3 or less of a sound velocity.
2. The plasma processing method described in 2. 19. The plasma processing method according to claim 12, wherein the gas supply is performed at a gas pressure in the processing chamber of 0.5 mTorr or less. 20. The plasma processing method according to claim 12, wherein the gas exhaust is performed for a gas residence time in the processing chamber of 50 msec or less. 21. The plasma processing method according to claim 12, wherein the gas is supplied at a flow rate of 40 sccm or more in the processing chamber. 22. The gas exhaust has an effective exhaust speed of 1300.
13. The plasma processing method according to claim 12, wherein the plasma processing is performed at 1 / sec or more. 23. The gas exhaust has an effective exhaust speed of 2000.
13. The plasma processing method according to claim 12, wherein the plasma processing is performed at 1 / sec or more. 24. The plasma processing method according to claim 12, wherein the gas supply is performed at a flow rate of the gas supplied into the processing chamber of 100 sccm or more. 25. The plasma processing apparatus according to claim 1, further comprising magnetic field applying means for promoting dissociation of gas plasma. 26. The plasma processing apparatus according to claim 1, wherein the electromagnetic wave introducing unit is a high frequency introducing unit. 27. A mechanism for plasma discharge, a gas introduction port, a gas exhaust port, means for holding an object to be processed in the vacuum processing chamber, means for introducing gas from the gas introduction port into the vacuum processing chamber, and the gas. In order to generate a gas plasma in the discharge part, it has a means for introducing an electromagnetic wave and a means for exhausting the gas plasma and the gas generated thereby from the vacuum processing chamber through the gas exhaust port at an effective exhaust speed of 800 l / sec or more. , A plasma processing apparatus for processing an object to be processed. 28. The plasma processing apparatus according to claim 27, wherein the electromagnetic wave introducing unit is a microwave introducing unit. 29. The means for introducing the etching gas includes an etching gas pipe, a tip gas introduction port of the etching gas pipe, a flow rate regulator of the etching gas, and the etching gas into the vacuum processing chamber. And means for controlling the flow velocity when it is introduced.
7. The plasma processing apparatus according to 7. 30. The means for controlling the flow velocity is a buffer portion provided at the gas inlet port.
7. The plasma processing apparatus according to 7. 31. The plasma processing apparatus according to claim 27, wherein the gas inlet has a plurality of holes. 32. The plasma processing apparatus according to claim 27, wherein the etching gas pipes are plural and are arranged substantially symmetrically with respect to a central axis of the vacuum processing chamber. 33. The plasma processing apparatus according to claim 27, wherein the gas introduction port is disposed substantially toward a central axis of the vacuum processing chamber. 34. The plasma processing apparatus according to claim 27, wherein the means for exhausting the inside of the vacuum processing chamber is an exhaust pump having an exhaust speed of 2000 l / sec or more. 35. The plasma processing apparatus according to claim 27, wherein the exhaust pump is a turbo molecular pump. 36. The plasma processing apparatus according to claim 27, wherein the means for changing the effective pumping speed by varying the pumping conductance is a conductance valve provided in a pumping section. 37. The exhaust means has a variable control valve for changing the exhaust speed of gas.
The plasma processing apparatus according to. 38. A mechanism for plasma discharge, a gas introduction port, a gas exhaust port, means for holding an object to be processed in the vacuum processing chamber, means for introducing gas into the vacuum processing chamber from the gas introduction port, In order to generate gas plasma in the discharge part, there are provided means for introducing electromagnetic waves, and means for exhausting the gas plasma and the gas generated thereby from the vacuum processing chamber through the gas exhaust port at an effective evacuation speed of 500 l / sec or more. The gas residence time to 300 msec or less,
A plasma processing apparatus for processing an object to be processed. 39. A mechanism for plasma discharge, a gas inlet, a gas outlet, a means for holding an object to be processed in a vacuum processing chamber, a means for introducing a gas from the gas inlet into the vacuum processing chamber, and the gas. In order to generate gas plasma in the discharge part, there are provided means for introducing electromagnetic waves and means for exhausting the gas plasma and the gas generated thereby from the vacuum processing chamber through the gas exhaust port at an effective exhaust speed of 800 l / sec or more. And a gas pressure of 5 mTorr or less, a plasma processing apparatus for processing an object to be processed. 40. A means for holding a target object at a position other than the ECR position in the vacuum processing chamber, which has a mechanism for plasma discharge, a gas inlet port, and a gas exhaust port, and introduces gas into the vacuum processing chamber from the gas inlet port. Means for introducing an electromagnetic wave in order to generate a gas plasma in the discharge part by the gas, the gas plasma and the gas generated thereby from the vacuum processing chamber through the gas exhaust port, and an effective evacuation speed of 500 l.
/ Sec or more, a plasma treatment method for treating an object to be treated, which has a means for exhausting. 41. The plasma processing method according to claim 40, wherein the effective pumping speed is changed during the pumping. 42. The treatment is at least 15 nm / mi.
The plasma processing method according to claim 40, wherein the gas is exhausted at an effective evacuation speed of 500 l / sec or more and the gas residence time in the processing chamber is 300 msec or less in the process of performing etching at an etching rate of n or more. 43. A gas pressure of the processing chamber is 5 m.
41. The method according to claim 40, wherein the operation is performed at less than Torr.
The plasma processing method described in 1. 44. The gas supply has a gas pressure of 1 in the processing chamber.
5. The process according to claim 4, wherein the process is performed at mTorr or less.
0. The plasma processing method described in 0. 45. The plasma processing method according to claim 40, wherein the gas exhaust is performed for a gas residence time in the processing chamber of 100 msec or less. 46. The gas introduction is performed at a gas flow velocity in the processing chamber of 1/3 or less of a sound velocity.
0. The plasma processing method described in 0. 47. The plasma processing method according to claim 40, wherein the gas supply is performed at a gas pressure in the processing chamber of 0.5 mTorr or less. 48. The plasma processing method according to claim 40, wherein the gas exhaust is performed for a gas residence time in the processing chamber of 50 msec or less. 49. The plasma processing method according to claim 40, wherein the gas supply is performed at a gas flow rate of 40 sccm or more supplied into the processing chamber. 50. The gas exhaust has an effective exhaust speed of 1300.
The plasma processing method according to claim 40, wherein the plasma processing method is performed at 1 / sec or more. 51. The gas exhaust has an effective exhaust speed of 2000.
The plasma processing method according to claim 40, wherein the plasma processing method is performed at 1 / sec or more. 52. The plasma processing method according to claim 40, wherein the gas supply is performed at a flow rate of the gas supplied into the processing chamber of 100 sccm or more. 53. A mechanism for plasma discharge, a gas introduction port, a gas exhaust port, means for holding an object to be processed in the vacuum processing chamber, means for introducing gas from the gas introduction port into the vacuum processing chamber, and the gas. In order to generate gas plasma in the discharge part, there are provided means for introducing electromagnetic waves and means for exhausting the gas plasma and the gas generated thereby from the vacuum processing chamber through the gas exhaust port at an effective exhaust speed of 800 l / sec or more. And a plasma processing method for processing an object to be processed at an etching rate of 50 nm / min or more. 54. A mechanism for plasma discharge, a gas introduction port, a gas exhaust port, means for holding an object to be processed in the vacuum processing chamber, means for introducing gas into the vacuum processing chamber from the gas introduction port, In order to generate gas plasma in the discharge part, there are provided means for introducing electromagnetic waves, and means for exhausting the gas plasma and the gas generated thereby from the vacuum processing chamber through the gas exhaust port at an effective evacuation speed of 500 l / sec or more. Then, a plasma processing method for processing an object to be processed having an etching rate of 50 nm / min or more and a gas residence time of 300 msec or less. 55. A mechanism for plasma discharge, a gas introduction port, a gas exhaust port, means for holding an object to be processed in the vacuum processing chamber, means for introducing gas from the gas introduction port into the vacuum processing chamber, and the gas. In order to generate gas plasma in the discharge part, there are provided means for introducing electromagnetic waves and means for exhausting the gas plasma and the gas generated thereby from the vacuum processing chamber through the gas exhaust port at an effective exhaust speed of 800 l / sec or more. Then, the plasma treatment method of treating the object to be treated at a gas pressure of 5 mTorr or less. 56. The height / width ratio of the vacuum processing chamber is 0.5.
It is above, The plasma processing apparatus of Claim 1 characterized by the above-mentioned. 57. The height-width ratio of the vacuum processing chamber is 0.5.
26. The plasma processing apparatus according to claim 25, which is the above. 58. The plasma processing apparatus according to claim 1, wherein the gas introduction port is arranged at a height within 1/3 of an upper portion of the vacuum processing chamber. 59. The plasma processing apparatus according to claim 25, wherein the gas inlet is arranged at a height within 1/3 of an upper portion of the vacuum processing chamber. 60. A flow rate regulator for the etching gas,
The plasma processing apparatus according to claim 1, which has a flow rate adjusting function of 40 sccm or more. 61. A flow rate regulator for the etching gas,
26. The plasma processing apparatus according to claim 25, which has a flow rate adjusting function of 40 sccm or more. 62. The plasma processing apparatus according to claim 1, wherein the sample stage is a flat table type and has a surface area of 5000 cm ² or more. 63. The plasma processing apparatus according to claim 25, wherein the sample stage is a flat table type and has a surface area of 5000 cm ² or more. 64. The plasma processing apparatus according to claim 1, wherein the means for introducing the etching gas into the vacuum processing chamber has a flow rate adjusting function of 100 sccm or more. 65. The plasma processing apparatus according to claim 25, wherein the means for introducing the etching gas into the vacuum processing chamber has a flow rate adjusting function of 100 sccm or more. 66. The gas exhausting means comprises a plurality of pumps installed in the same vacuum processing chamber, and the exhaust port connecting the pumps and the vacuum processing chamber is axially symmetrical with respect to the central axis of the wafer. A plasma processing apparatus, characterized in that the plasma processing apparatus is arranged in the. 67. The plurality of pumps are exhaust pumps each having an exhaust speed of 500 l / sec or more, and
The total pumping speed of all pumps is 2000 l / sec
A plasma processing apparatus having the above features. 68. The plasma processing apparatus according to claim 1, wherein the gas exhausting means comprises a plurality of pumps installed in the same vacuum processing chamber. 69. The plasma processing apparatus according to claim 27, wherein the gas exhausting means comprises a plurality of pumps installed in the same vacuum processing chamber. 70. The plurality of pumps are arranged in axial symmetry with respect to the wafer central axis, and an exhaust port connecting the pump and the vacuum processing chamber is arranged in axial symmetry with respect to the wafer central axis. The plasma processing apparatus of claim 1, wherein the plasma processing apparatus is a plasma processing apparatus. 71. The plurality of pumps are arranged in axial symmetry with respect to the wafer central axis, and an exhaust port connecting the pump and the vacuum processing chamber is arranged in axial symmetry with respect to the wafer central axis. 28. The plasma processing apparatus according to claim 27, wherein the plasma processing apparatus is a plasma processing apparatus. 72. The effective pumping speed S0 is represented by the following formula by the pumping speeds S1 to Sn (n is a numerical value indicating the number of pumps) of a plurality of exhaust pumps and the exhaust conductance C of the vacuum processing chamber, and The plasma processing apparatus according to claim 1, wherein the effective pumping speed S0 is set to 2/3 or more of the total pumping speed. 1 / S0 = (1 / ΣSn) + 1 / C 73. The effective pumping speed S0 is expressed by the following equation by the pumping speeds S1 to Sn (n is a numerical value indicating the number of pumps) of a plurality of exhaust pumps and the exhaust conductance C of the vacuum processing chamber, and 26. The plasma processing apparatus according to claim 25, wherein the effective pumping speed S0 is set to 2/3 or more of the total pumping pumping speed. 1 / S0 = (1 / ΣSn) + 1 / C 74. The size of the discharge part is such that the diameters of the upper end and the lower end are changed, the lower end diameter is larger than the upper end diameter, and the lower end portion is located above the height of the wafer during etching. The plasma processing apparatus according to claim 1.