JPS6235624A - Microwave processor - Google Patents

Abstract

PURPOSE:To make it possible to process microwaves with high precision by a method wherein a microwave processor is equipped with a microwave irradiating part and an electric field control jig to control the microwave values. CONSTITUTION:A total controller 22 compares and evaluates the measured temperature data on a point 18 on a wafer 4 with the same data on another point 20 on the wafer 4 according to the preliminarily set up processing requirement data 23 to feed controlled output 26 to a microwave transmitter 7 corresponding to the results of comparison and evaluation for controlling the microwave output transmitted from the microwave transmitter 7. On the other hand, almost simultaneously, position control values 27, 28 are respectively fed to motors 16, 17 and electric field control jigs 14, 15 are position-controlled to control the microwave intensity of irradiating microwaves 12, 13. Besides, stage revolution control valve 29 is fed to a stage controller 5 to control the revolution of an adsorbing pin stage 2. Through these procedures, the microwaves can be processed with high precision.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to microwave processing technology, and relates to a technology that is effective when applied to devices that utilize microwaves, such as microwave heating devices and microwave plasma reaction processing devices. .

[Background technology]

As is well known, microwave application technology is used not only for heating devices such as microwave ovens, but also for plasma dry etching processing equipment used to form patterns on semiconductor thin plates (wafers) in semiconductor device manufacturing. Alternatively, it is applied to a plasma processing apparatus such as a plasma CVD processing apparatus used to generate a protective film (passivation film) such as a PSG (phosphosilicate glass) film on a wafer surface to protect element characteristics. For example, Japanese varnish
“Solid State Technology” published by Niss.T. Co., Ltd.
y) As stated in Japanese version J October 1981 issue, published October 15, 1981, pages 63 to 70,
Microwave-based beta processors have also been developed.

Incidentally, semiconductor device manufacturing equipment that requires higher temperature accuracy must have even higher performance. In other words, the load capacity of the wafer, which is the object to be heated, differs depending on the product type, and the load capacity is extremely small. Therefore, even if the same microwave power is irradiated into the heating furnace, different reflected waves will occur depending on the type of product. The inventors have found that the standing wave intensity distribution, which is a combination of waves and reflected waves, differs from process to process, making it impossible to heat uniformly and accurately.

[Purpose of the invention]

An object of the present invention is to provide a microwave processing device capable of highly accurate processing.

Another object of the present invention is to provide a microwave processing device capable of efficient processing.

The above objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

That is, when the microwave processing apparatus of the present invention heats the wafer by irradiating the wafer with microwaves, it monitors the temperature of a desired location on the wafer and, based on this monitor information, adjusts the temperature of the stage that supports and rotates the wafer. Stage rotation control amount.

Output control amount of the microwave generator that generates microwaves,
By controlling the position control amount of the electric field control jig that operates the amount of microwave irradiation during microwave irradiation, the main surface of the wafer can be heat-treated uniformly and with high precision.
Fine patterning can be achieved in pattern formation in subsequent steps.

[Example 1] Fig. 1 is a schematic diagram showing an overview of a microwave heat treatment apparatus according to an embodiment of the present invention, Fig. 2 is a schematic plan view as well, and Fig. 3 is another embodiment of the present invention. FIG. 1 is a schematic diagram showing an outline of a microwave heat treatment apparatus according to the present invention.

In this example, a semiconductor thin film (
An example in which a photoresist film formed on the surface of a wafer is subjected to a hazing process using microwaves will be described.

In this microwave processing apparatus, a semiconductor thin plate (wafer) 4 having a resist film 3 formed on its main surface (upper surface) is attracted to a suction bin stage 2 in a furnace body 1 . This suction pin stage 2 is rotationally controlled by a stage controller 5.

On the other hand, a ring waveguide 6 configured in a ring shape is arranged around the furnace body 1. A supply waveguide 8 to which a microwave generator 7 is connected is connected to the ring waveguide 6 so that the microwave 9 generated from the microwave generator 7 is guided into the ring waveguide 6. It has become. The ring waveguide 6 is provided with a pair of microwave irradiators 10.degree.
The inside of the furnace body 1 is irradiated as 13. Further, in the ring waveguide 6 portion facing the microwave irradiation 10.11,
Electric field control jigs 14 and 15 are provided. These electric field control jigs 14 and 15 are connected to the motor 1 as shown in FIG.
Rotational position divided by 6.17? It is designed to be used. In FIG. 1, the supply waveguide 8 is depicted as being disposed at the same position as one of the microwave irradiators 10, but in reality, as shown in FIG. It is arranged in the middle of the pair of microwave irradiators 10 and 11, that is, at a position shifted by 90 degrees. Therefore, the microwave 9 passes between the microwave irradiation 10.11 and the electric field control jig 14.15 facing it, that is, along the direction perpendicular to the plane of the paper. For this reason, the electric field control jigs 14 and 15 are rotated by controlling the motors 16 and 17.
When approaches the microwave irradiation 10.11, the leakage amount (irradiation amount) of the irradiation microwave 12.13 into the furnace body 1 increases, and the heating temperature of the wafer 4 increases.

Conversely, when the microwave irradiation 10, 11 moves away from the electric field control jigs 14, 15, the irradiation microwave 12, 13
The amount of leakage (irradiation amount) into the furnace body 1 becomes smaller, and the heating temperature of the wafer 4 becomes lower.

On the other hand, the temperature at point A 18 on the wafer 4 is monitored by the temperature monitor 19, and the temperature at point 8 2o on the wafer 4 is monitored by the temperature monitor 21.
The temperature is measured by each.

The overall control unit 22 of this microwave processing apparatus uses the measured temperature IHI 24 of point A] 8 on the wafer 4 and the measured temperature information 25 of the 8 points 20 on the wafer 4 based on the roughly set processing condition information 23. is compared and evaluated, and an output control amount 26 is instructed to the microwave generator 7 according to the result, thereby controlling the amount of microwave output generated from the microwave generator 7.

On the other hand, at the same time, the motors 16 and 17 are instructed to control the positions 27 and 28, and the electric field control jigs 14 and 15 are controlled in position, and the irradiation microwaves 12 and 12 are controlled.
], 3 to control the microwave intensity. Further, the stage rotation control amount 29 is instructed to the stage control section 5 to control the rotation of the suction pin stage 2. By automatically feedback-controlling these, uniform and highly accurate photoresetting processing can be performed.

Note that bellows 30 for preventing microwave leakage are attached to the electric field control jigs 14 and 15 to prevent microwave leakage. Furthermore, in order to improve heating efficiency and heating controllability, the suction pin stage 2 is made of a material such as polytetrafluoroethylene resin that transmits microwaves.

This makes it possible to heat only the wafer 4 to be processed, thereby greatly improving heating efficiency and heating temperature control.

Next, a method of baking a photoresist film formed on a wafer surface using this apparatus will be explained.

The photoresist film may be a coated photoresist film before exposure processing, or a photoresist film that has been subjected to exposure processing, but the processing is substantially the same. During this wafer processing, the wafer 4 on which the resist film 3 to be processed (indicated by the thick line in the figure) has been formed is first placed on the suction pin stage 2, and the processing temperature, processing time, stage rotation, etc. Photoresist baking process information such as the number of photoresist baking processes is set as process condition information 23 in the overall control unit 22, and then the operation of the apparatus is started.

The wafer 4 is rotated at a predetermined rotational speed while being attracted to the suction pin stage 2 by the stage control section 5. Thereafter, the microwave generator 7 with an appropriate output is irradiated with the microwave. This microwave generator 7 is propagated to the ring waveguide 6, and is irradiated to the furnace body 1 as microwave irradiation 10.11 to irradiation microwave 12.13, thereby heating the wafer 4.

In order to uniformly and accurately heat the wafer 4 to be processed,
A of the wafer 4 is controlled by the temperature monitor 19 and the temperature monitor 21.
Temperature measurements are taken at points 18 and 8 points 20. In accordance with this measurement result, the overall control section 22 controls the amount of microwave output generated from the microwave generation section 7, and also controls the position of the electric field control jig 14, 15, and irradiates the microwave 12.
The resist film 3 is baked on the wafer 4 by uniformly and precisely heating it at a predetermined temperature profile while controlling the microwave intensity of the resist film 13 . When the baking process for the wafer 4 for a predetermined period of time is completed, the microwave from the microwave generator 7 is cut off, and the photoresist baking process is completed.

[Example 2] FIG. 3 is a schematic diagram showing another example of the present invention. This example shows an example in which the present invention is applied to a technique for forming a protective film on a wafer surface.

The difference between this apparatus and the first embodiment is that the inside of the furnace is kept in a vacuum state, a strong magnetic field and microwaves are applied thereto, and the wafer is set in that area, and at the same time the reaction gas necessary for forming the protective film is supplied. , a reactive gas is turned into plasma by the action of a magnetic field and microwaves, and a protective film is formed on the wafer surface by this plasma reaction.

In this Example 2, as a means of controlling the irradiated microwave intensity, the thickness of the protective film formed on the wafer is monitored;
The irradiated microwave intensity is controlled according to the measurement results based on the same principle as in the above-mentioned embodiment. The configuration of the device will be explained below. Note that the explanation of the same parts as in the above embodiment will be omitted, and the same parts will be given the same reference numbers.

In the microwave processing apparatus of this embodiment, a wafer 4 is set on a wafer stage 31 within the furnace body 1.

On the other hand, a ring-shaped waveguide is disposed around the outer periphery of the furnace body 1, as in the first embodiment. However, this ring waveguide 6
A shield body 32 made of quartz or the like that transmits the microwave 9 and is capable of vacuum shielding is attached to the microwave irradiation 10.11. Further, magnets 33 are set so as to surround the furnace body 1, so that a strong magnetic field acts within the furnace body 1. Further, the inside of the furnace body 1 is evacuated by a vacuum evacuation section 34 to maintain a high vacuum.

On the other hand, a reaction gas 37 necessary for forming a protective film 36 is supplied into the furnace body 1 from a reaction gas supply section 35 . . Further, the thickness of the formed protective film 36 is measured by measuring the thickness of the protective film 36 at points A 18 and 8 20 on the wafer 4 using film thickness monitors 38 and 39. Further, a vacuum shield body 40 made of a material that does not interfere with the film thickness monitor is attached to the monitor window portion of the film thickness monitor 38, 39, and the vacuum shield of the furnace body 1 is maintained.

In this device, the electric field control jigs 14 and 15 are rotationally controlled according to the protective film thickness information measured by the film thickness monitors 38 and 39 based on the same principle as in Example 1, and the microwave irradiation intensity applied to the wafer 4 is controlled. is controlled by the control section.

Note that, unlike the first embodiment, protective film formation processing condition information 41 is set in the overall control unit 22 as processing condition setting information. As this information, information such as the degree of vacuum in the furnace body 1, magnetic field strength, microwave strength 2, reaction gas supply amount, and protective film thickness is set.

The overall control section 22 compares the film thickness measurement information 42, 43 of the protective film from the film thickness monitors 38, 39 based on the above-mentioned cent information, and compares the film thickness measurement information 42, 43 of the film thickness monitor 38, 39 with the evacuation section 34. Magnet 33° Microwave generator 7
．． Electric field control jigs 14, 15 (motors 16, 17) and reaction gas supply section 35 each have a displacement of 44. Electromagnetization amount 45. Each part is controlled by specifying the output control amount 26° and the gas supply amount 46. As a result, a homogeneous film with a uniform thickness is formed on the main surface of the wafer 4 with high precision.

〔effect〕

(1) When the microwave processing apparatus of the present invention performs heat treatment on the object to be processed or causes a reactant to act on the object, the microwave processing apparatus directly heats the object or reacts with the material using microwaves. Direct action provides the effect of efficient processing.

(2) According to (1) above, the microwave processing apparatus of the present invention has a structure in which microwaves are applied directly to the object to be processed, so that the heating energy capacity or reaction energy capacity is minimized. Therefore, it is possible to achieve the effect that reduction of the microwave output, that is, miniaturization of the microwave generation section, can be sufficiently achieved even in an apparatus having a microwave generation section.

(3) According to (1) above, the microwave processing apparatus of the present invention can efficiently heat the object to be processed, thereby shortening the processing time and improving productivity. .

(4) In addition to the above (11), the microwave processing apparatus of the present invention monitors the processing state of a desired position of the object to be processed, and uses microwaves (irradiation microwaves) that act on the object to be processed based on this monitor information. ), it is possible to perform uniform and highly accurate processing, resulting in the effect that quality can be improved.

(5) According to (1) and (4) above, the microwave processing device of the present invention has a small heating capacity and is capable of high-speed heating control, so heating rise time, heating temperature profile, etc. can be freely controlled. As a result, it is possible to provide a highly flexible heat treatment apparatus that can accommodate various process specification variations.

(6) When the microwave treatment apparatus of the present invention performs microwave reaction treatment on the object to be treated using a reactive substance, only the substance that requires reaction can be subjected to the reaction treatment, so that unnecessary products are not generated as in the conventional method. This reduces the amount of waste material that adheres to the inner walls of the processing chamber, thereby preventing contamination of the objects to be processed with these filthy substances, resulting in the production of products of excellent quality at a high yield.

(7) Since the microwave processing apparatus of the present invention has a structure in which microwaves are applied directly to the object to be processed,
Since the microwave processing efficiency is increased and it is possible to perform single-wafer (individual) processing of the objects to be processed, it is possible to achieve the effect that the device structure can be simplified and miniaturized.

(8) Due to the above (7), the microwave processing apparatus of the present invention can be easily incorporated into a production line, so that automatic continuous processing is possible.

(9) According to (1) to (8) above, according to the present invention, uniform and highly accurate heating or reaction treatment can be stably performed in a highly pure state with little contamination, resulting in excellent quality and A synergistic effect can be obtained in that it becomes possible to perform processing with high reliability and improve yield, which also makes it possible to reduce product costs.

Although the invention made by the present inventor has been specifically explained based on Examples above, the present invention is not limited to the above Examples, and various modifications can be made without departing from the gist thereof. Needless to say, for example, the present invention enables the above-mentioned treatment in a high-pressure atmosphere, a normal-pressure atmosphere, a low-pressure atmosphere, a vacuum, a substance that transmits microwaves, etc. effect can be obtained.

[Application field]

The above explanation has mainly been about an example in which the invention made by the present inventor is applied to semiconductor device manufacturing equipment, which is the background field of application, but is not limited thereto. For all substances that have a magnetic loss effect, apply to crystal growth methods, impurity diffusion methods, crystal annealing methods, plasma processing methods, film formation processing methods, microwave heat treatment technology, microwave reaction treatment technology, etc. be able to.

The present invention is applicable to at least technology using microwaves.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the outline of a microwave heat treatment apparatus according to an embodiment of the present invention, FIG. 2 is a schematic plan view as well, and FIG. 3 is a microwave heat treatment according to another embodiment of the present invention. FIG. 1 is a schematic diagram showing an outline of the device. DESCRIPTION OF SYMBOLS 1... Furnace body, 2... Adsorption bin stage, 3... Resist film, 4... Wafer, 5... Stage control unit,
6... Ring waveguide, 7... Microwave generator, 8
...Supply waveguide, 9...Microwave, 10.11.
...Microwave irradiation, 12.13...Microwave irradiation, 14.15...Electric field control jig, 16.17...Motor, 18...Point A, 19...Temperature monitor, 2o・
... Point B, 21... Temperature monitor, 22... Overall control unit, 23... Processing condition information, 24... Measured temperature information, 25... Measured temperature information, 26... Output control amount, 2
7.28... Position control amount 29... Stage rotation control amount, 3o... Bellows, 31... Wafer stage,
32... Shield body, 33;... Magnet, 34... Vacuum exhaust section, 35... Reactive gas supply section, 36... Protective film, 37... Reactive gas, 38.39... Film thickness monitor, 40... Shield body, 41... Protective film formation processing condition information, 42. 43... Film thickness measurement information, 44... Exhaust volume, 45... Electromagnetization amount, 46. ...Gas supply amount.

Claims (1)

[Scope of Claims] 1. An apparatus for performing microwave treatment by irradiating a workpiece with microwaves, comprising: a microwave irradiation section disposed so as to surround the workpiece; and the microwave irradiation section. and an electric field control jig for controlling the amount of microwaves irradiated from the microwave irradiation port to the object to be processed. 2. Claim 1, characterized in that the electric field control jig is controlled based on information obtained by monitoring the processing status of a plurality of points on the object to be processed and processing information set in advance. The microwave processing device described.