JPS63141317A - Etching treatment device - Google Patents

Abstract

PURPOSE:To make the speed of etching constant, and to perform a uniform etching treatment by a method wherein the substrate to be treated is heated up or cooled down by innert gas before performance of an etching treatment, and the etching treatment is started after the substrate to be treated has been maintained at a fixed temperature. CONSTITUTION:When a wafer 3 is placed on a lower electrode 5, the temperature in a reaction chamber 4 is measured from outside a reaction container 2 by a noncontact type wafer temperature detecting part 24, and the temperature of the wafer 3 is detected. The detected temperature value is outputted to a treatment part 25. A cooling device 35, a heating device 36 and a flow-passage switching device 37 are controlled by the treatment part 25 in accordance with said temperature information. To be more precise, when the temperature is higher than the standard temperature set in advance, cooled innert gas is supplied to the wafer 3. On the other hand, when the temperature of the wafer 3 is lower than the standard temperature, heated innert gas is supplied. As a result, the wafer 3 can be maintained at a fixed temperature before the etching treatment is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for manufacturing semiconductor devices, and particularly to an etching apparatus used in a dry process in a wafer process.

[Conventional technology]

Fig. 2 is a vertical cross-sectional view schematically showing a plasma etching processing apparatus or a reactive ion etching processing apparatus, which is one of the conventional etching processing apparatuses, and Fig. 3 is a vertical sectional view showing the outline of a plasma etching processing apparatus or a reactive ion etching processing apparatus, which is one of conventional etching processing apparatuses.
-m line sectional view, the etching processing apparatus 1 is equipped with a cylindrical reaction vessel 2, and this reaction vessel 2 forms a reaction chamber 4 that accommodates a wafer 3 as a substrate to be processed and is maintained at a predetermined degree of vacuum. has been done. A flat lower electrode 5 for supporting the wafer 3 is disposed near the center of the reaction chamber 4 .

Reference numeral 6 denotes a flat upper electrode that faces the lower electrode 5 in parallel with the wafer 3 interposed therebetween, and these electrodes protrude outside the reaction vessel 2 through the sealing material 7 and the insulating structure. The upper electrode 6 is grounded by a conductor 8, and a gas introduction passage 9 opened toward the lower electrode 5 is provided in the center thereof, and a reaction gas supply pipe 10 is connected to the base end thereof. . On the other hand, the lower electrode 5 has a structure on which the wafer 3 can be placed, and a high frequency power source 11 is connected to the lower part through a rectifier (not shown).
is connected. Reference numeral 12 denotes a conductor for grounding the high frequency power source 11.

13 is an annular groove provided at the bottom peripheral edge of the reaction vessel 2;
An exhaust port 14 for exhausting and reducing the pressure inside the reaction chamber 4 is provided on the bottom surface of the annular 'a13. This exhaust port 14 is the exhaust pipe 1
The reaction chamber 4 is connected to a vacuum pump (not shown) via 5.
This is to evacuate the inside to a predetermined degree of vacuum. 1
Reference numeral 6 denotes an exhaust adjustment plate that covers the annular groove 13 and has through holes formed at equal intervals in order to obtain an average exhaust.

Etching of the wafer 3 is performed by first placing the wafer 3 on the lower electrode 5. Next, the inside of the reaction chamber 4 is made airtight and the exhaust port 1 is closed.
4, the residual gas in the reaction chamber 4 is exhausted. Then, when the inside of the reaction chamber 4 reaches a predetermined degree of vacuum, a reaction gas is introduced from the gas introduction path 9.

Here, the high-frequency power supply 11 is activated to apply a high-frequency voltage to the lower electrode 5 to generate a glow discharge between the lower electrode 5 and the upper electrode 6. Therefore, plasma is formed, and a predetermined pattern on the wafer 3 is etched by a physicochemical reaction in the plasma.

[Problems to be Solved by the Invention] However, in this kind of conventional etching processing apparatus, there is a problem that uniform etching processing cannot necessarily be performed. This is because the lower electrode 5 and wafer 3 in the reaction chamber 4 are heated by etching caused by a physicochemical reaction.
As the number of wafers 3 processed increases, the temperature inside the reaction chamber 4 gradually rises and finally reaches a nearly constant state. During this rising process, the etching rate S increases as shown in FIG. This is thought to be because it changes depending on the temperature T.

That is, the first wafer in the loft is etched while the temperature inside the reaction chamber 4 is low, whereas the wafers to be processed later are etched while the temperature inside the reaction chamber 4 is high. As a result, this temperature difference affects the machining and notching speed. Further, once the processing of this loft is finished, the temperature inside the reaction chamber 4 drops until the processing of the next loft is started.

Therefore, the temperature conditions for each wafer are different, which affects the etching rate, resulting in non-uniform etching and variations in products.

The present invention was devised in view of the above circumstances, and its object is to provide an etching processing apparatus that can uniformly perform etching processing.

[Means for solving problems]

The etching processing apparatus according to the present invention includes: a temperature measuring device that measures the temperature of the substrate to be processed or the inside of the reaction chamber; a temperature adjusting device that selectively heats and cools an inert gas according to the temperature measured by the device; and an inert gas supply device that supplies the inert gas to the substrate to be processed.

[Effect]

In the present invention, the substrate to be processed can be heated or cooled with an inert gas before the etching process, and etching can be started after holding the substrate at a constant temperature. Therefore, the temperature conditions for each substrate to be processed are becomes constant.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical cross-sectional view schematically showing an etching processing apparatus according to the present invention. In the figure, the reference numeral 21 indicates a plasma processing apparatus, and like the conventional one, a reaction chamber containing a wafer 3 is shown. 4, and a lower electrode 5 and an upper electrode 6 disposed within the reaction container 2. The lower electrode 5 supports the wafer 3, and the lower part protrudes outside the reaction vessel 2 via the sealing material 7, and the conductor 12
It is connected to a high frequency power source 11 which is grounded. The upper electrode 6 has a gas introduction path 9 to which a reaction gas supply pipe 10 is connected, and is grounded by a conducting wire 8. An annular groove 13 covered with an exhaust adjustment plate 16 is provided at the bottom of the reaction vessel 2, an exhaust port 14 is opened here, and an exhaust pipe 15 is connected to the annular groove 13.

22 is a temperature measuring device for measuring the temperature of the wafer 3. This temperature measuring device 22 includes a wafer temperature detecting section 24 provided in a cylindrical section 23 opened toward the center on the side of the reaction vessel 2, processing of data detected by this detecting section 24, and input/output of signals. It is composed of a processing section 25 that performs. The wafer temperature detection section 24 is a non-contact type that detects the temperature of the wafer 3 by measuring the temperature inside the reaction chamber 4 through a transparent window (not shown) using, for example, infrared rays.

Reference numeral 31 denotes a supply section provided on the lower electrode 5 and forming a gap between the lower electrode 5 and the back surface of the wafer 3 held on the lower electrode 5 by a wafer holder (not shown). Reference numeral 32 denotes an inert gas introduction path provided in the lower electrode 5 and communicating between the supply section 31 and the outside of the reaction vessel 2, and an inert gas supply pipe 33 is connected to the outer open end. Although not shown, the upstream side of the inert gas supply pipe 33 is connected to an inert gas supply source such as He. That is, supply section 31° inert gas introduction path 32. The inert gas supply pipe 33 and an inert gas supply source (not shown) constitute an inert gas supply device that supplies inert gas to the wafer 3 from the back side. The inert gas supply pipe 33 is branched into a cooling side passage 33a and a heating side passage 33b, and a cooling device 35 for cooling the inert gas is attached to the cooling side passage 33a, and an inert gas supply pipe 33 is attached to the heating side passage 33b. A heating device 36 is attached to heat the gas. Further, these passages are again combined via a flow path switching device 37 on the downstream side of the device.

The processing section 25 is connected to a cooling device 35 and a heating device 36 via a signal line 41, and controls so that either the cooling device 35 or the heating device 36 is selectively activated. Further, the flow path switching device 37 is connected to the processing section 25 via a signal line 42, and is controlled to flow inert gas into the path on the side where the cooling device 35 or the heating device 36 is operating. That is, these cooling devices 35° and heating devices 36. The flow path switching device 37 is connected to the temperature measuring device 22
This constitutes a temperature adjustment device that selectively heats and cools the inert gas according to the temperature measured in the inert gas.

45 is a constant temperature water supply pipe, 46 is a constant temperature water discharge pipe, these are connected to both ends of a flow path (not shown) provided in the lower electrode 5, and the temperature of the wafer 3 increases during the etching process, thereby damaging the resist pattern. In order to prevent this, constant temperature water is circulated within the lower electrode 5.

In the etching processing apparatus configured in this way,
When the wafer 3 is placed on the lower electrode 5, the non-contact wafer temperature detection section 24 detects the temperature of the reaction chamber 4 from outside the reaction chamber 2.
The temperature of the wafer 3 is detected by measuring the temperature inside the wafer 3, and this detected value is output to the processing section 25. Processing section 2
Based on this temperature information, cooling device 35 and heating device 36 . Controls the flow path switching device 37.

That is, when the temperature is higher than the preset standard temperature, the cooling device 35 is activated and the cooling side passage 33a is opened (
A signal is sent to activate the flow path switching device 37 in this manner.

Therefore, cooled inert gas is supplied to the wafer 3 so that the wafer 3 has a constant temperature. On the other hand, if the temperature of the wafer 3 is low, the processing section 25 sends a signal to operate the heating device 36 and the channel switching device 37 to open the heating side passage 33b, so that the wafer 3 is kept at a constant temperature. A heated inert gas is supplied so as to heat it to a temperature of . As a result, the wafer 3 can be maintained at a constant temperature before the etching process.

When the wafer temperature detection unit 24 detects that the temperature of the wafer 3 has become constant, the cooling device 35 and the heating device 36 are stopped, and the inert gas supply pipe 33 is switched to the flow path switching device 37. It is considered to be in a closed state. after that,
When the inside of the reaction chamber 4 reaches the set degree of vacuum, the reaction gas flows from the reaction gas supply pipe 10 through the gas introduction path 9 in the direction indicated by the arrow A.
It is introduced into the reaction chamber 4 as shown in . Here, the high frequency power supply 11 is activated and a high frequency voltage is applied to the lower electrode 5, so that a glow discharge occurs between it and the upper electrode 6, plasma is formed, and the wafer 3 is etched.

Therefore, since etching can be started after the wafer 3 is maintained at a constant temperature before the etching process, the temperature conditions for each wafer 3 can be kept constant. That is, although the temperature gradually increases in the etching process, by keeping the temperature constant before the etching process, the temperature rise of each wafer can be made equal.

In addition, since the wafer temperature during etching processing can be monitored by the wafer temperature detection section 24, if the temperature of the wafer 3 becomes abnormal with respect to the standard temperature, an alarm signal can be output or the etching processing device It is also possible to output a signal to stop 21.

As described above, the present invention involves supplying an inert gas to the wafer 3 and maintaining the wafer 3 at a constant temperature before the etching process. The material is not limited to being supplied from the back side, but may be supplied from the front side of the wafer 3.

Further, the same functions can be obtained as a temperature measuring device 22 that measures the temperature of the wafer 3 or the reaction chamber 4, a temperature adjusting device that selectively heats and cools an inert gas, and a gas supply device that supplies an inert gas. If so, its structure can be changed as appropriate.

For example, as the temperature measuring device 22, the blow μ may be formed of quartz fiber or the like, and this may be held by a holding means consisting of an arm or the like that moves forward and backward with respect to the wafer.

In this way, the temperature can be measured by contacting the wafer, and during the etching process, it can be avoided near the peripheral wall of the reaction vessel so as not to be affected by the plasma. Furthermore, the wafer temperature can be monitored by bringing the blow μ into contact with the periphery of the wafer that does not affect the etching during the etching process, and the temperature can be used as an alarm signal or the like.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a temperature measuring device that measures the temperature of a substrate to be processed or a reaction chamber, and a temperature adjusting device that selectively heats and cools an inert gas according to the temperature measured by the device. and an inert gas supply device for supplying the inert gas to the substrate to be processed, the substrate to be processed is heated or cooled by the inert gas and the substrate to be processed is maintained at a constant temperature before the etching process. Then you can start etching.

Therefore, the temperature conditions for each substrate to be processed can be made constant regardless of whether the loft is processed continuously or intermittently, or the order in which the processing is performed within the loft. , the etching speed can be kept constant and the etching process can be performed uniformly. As a result, by using a substrate etched in this manner, the quality of the product can be improved.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view schematically showing an etching processing apparatus according to the present invention, FIG. 2 is a vertical cross-sectional view schematically showing a conventional etching processing apparatus, and FIG. 3 is a cross-sectional view taken along the line III--III in FIG. , FIG. 4 is a graph showing the relationship between temperature and etching rate. 29. ... Reaction container, 3 ... Wafer, 5 ... Lower electrode, 6 ... Upper electrode, 24 ... Wafer temperature detection section, 25 ... Processing section, 33 ... - Inert gas supply pipe, 35... cooling device, 36... heating device, 37... flow path switching device.

Claims (1)

[Claims] A reaction chamber forming a reaction chamber having an exhaust port for accommodating a substrate to be processed and having an exhaust port for evacuation and decompression and a gas inlet for introducing a reaction gas, and a pair of electrodes facing each other with the substrate to be processed interposed therebetween. An etching processing apparatus comprising: a temperature measuring device for measuring the temperature of the substrate to be processed or the inside of the reaction chamber; and a temperature adjusting device for selectively heating and cooling an inert gas according to the temperature measured by the device. and an inert gas supply device that supplies the inert gas to the substrate to be processed.