JPS63190340A - Light treatment device - Google Patents

Abstract

PURPOSE:To contrive improvement in treatment efficiency of a lamp treatment by a method wherein a temperature sensor is buried in the prescrived part of the lamp, a cooling mechanism is controlled by a control part based on the signal sent from said temperature sensor, and the temperature control on the area in the vicinity of the prescrived section is performed. CONSTITUTION:The temperature sensor 7 such as a thermoelectric couple and the like is buried in a block member 6, and the sensor is arranged at the position contacting to the tube wall of a lamp. A cooling mechanism 8, with which said block member 6 is cooled, is conjointly provided in the vicinity of the block member 6. Any type of cooling means such as water-cooling and the like, for example, can be used as the above-mentioned cooling mechanism 8. This cooling mechanism 8 is constructed in such a manner that its operation is controlled by a control part 9, the temperature sensor 7 buried in the block member 6 is connected to the control part 9, and a temperature signal is transmitted to the control part 9. Accordingly, the temperature condition of a lamp can be controlled in such a manner that the prescrived intensity of light projected from the lamp is always maintained at an appropriate value. As a result, the improvement in efficiency of the lamp treatment can be achieved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a technique that is particularly effective when applied to a lamp processing apparatus that processes a workpiece with light of a predetermined wavelength. The present invention relates to a technique that is effective when used in a resist removal apparatus that removes photoresist material on a semiconductor wafer by irradiating ultraviolet rays.

[Conventional technology]

Regarding the removal technology of resist material deposited on semiconductor wafers, for example, see Maruzen Co., Ltd., November 25, 1960.
It is described in "Integrated Circuit Handbook JP267" published by Japan, and several types of resist removal methods are explained here.

The present inventor studied the resist removal technique as described above. Although the following is not a publicly known technique, it is a technique studied by the present inventor, and its outline is as follows.

That is, after forming a predetermined circuit pattern on a semiconductor wafer, a resist removal step is required to remove unnecessary resist material from the wafer surface. As a means of removing such resist, a semiconductor wafer coated with a resist material and heated to a predetermined state is irradiated with ultraviolet rays using a low-pressure mercury lamp, etc., and ozone and oxygen gas are applied to the surface of the semiconductor wafer. A technique for supplying a gas mixture with is known. In other words, chemically active oxygen radicals generated by the dissociation of oxygen and ozone excited by ultraviolet rays oxidize the resist material made of organic substances and convert it into carbon dioxide gas, water vapor, etc. It is removed from the surface.

By the way, in order to improve the efficiency of resist removal as described above, it is conceivable to increase the output of the low-pressure mercury lamp to increase the relative intensity of ultraviolet rays directed to the resist material.

[The li, 'JM point that the invention attempts to solve] However,
In reality, the output of this low-pressure mercury lamp is not proportional to the light intensity of ultraviolet rays; rather, the light intensity of ultraviolet rays emitted from a low-pressure mercury lamp peaks under the specified temperature conditions of the low-pressure mercury lamp. It has become clear from the experimental results by the present inventors that this value is shown.

Figure 2 is an explanatory diagram showing the relationship between the coldest point temperature and light intensity of a low-pressure mercury lamp.The vertical axis shows the light intensity P, expressed as relative intensity whose peak value is 100%. It is. Moreover, the horizontal axis represents the temperature T at the coldest point of the lamp. The coldest point is the lowest temperature point set in the low-pressure mercury lamp. That is, by measuring this coldest point temperature T, the temperature state of the low-pressure mercury lamp itself can be known. In addition, the curve indicated by 11 in the figure shows the light intensity-coldest point temperature characteristic of the ultraviolet wavelength of λ = 254 nm, for example, and the curve indicated by
For example, it shows the light intensity-coldest point temperature characteristic of an ultraviolet wavelength of λ=185 nm.

This figure 2 also shows that the coldest spot temperature T and the light intensity P are not proportional, and the coldest spot temperature value corresponding to each wavelength is −3= constant, that is, 'r,..., TP2. It can be understood that the light intensity P has a characteristic of being a peak value.

The present invention has been made focusing on the above problems,
The purpose is to provide a lamp processing technology with high processing efficiency.

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

Kinuta's Means for Solving Problem C] A brief summary of typical inventions disclosed in this application is as follows.

That is, a temperature sensor is embedded in a predetermined portion of the lamp, and a cooling mechanism is controlled by a control section based on a signal from the temperature sensor, thereby controlling the temperature in the vicinity of the predetermined portion.

[Effect]

According to the above means, the temperature condition of the lamp can be controlled so that the intensity of the predetermined light irradiated from the lamp always maintains an appropriate value, so that the processing efficiency in lamp processing can be improved. becomes possible.

〔Example〕

FIG. 1 is an explanatory diagram showing a resist removing apparatus which is an embodiment of the present invention.

The resist removing apparatus 1 of this embodiment is for removing a resist material 3 applied to the surface of a semiconductor wafer 2. As shown in FIG.

The resist removing apparatus 1 of this embodiment has an interior partitioned by a transparent plate 4 made of synthetic quartz or the like, and has a light source chamber A in the upper part and a processing chamber B in the lower part. In FIG. 1, a low-pressure mercury lamp 5 for irradiating ultraviolet rays is arranged in the upper light source chamber A. This low-pressure mercury lamp 5 has its electrode portion covered with a block member 6 made of aluminum alloy or the like, and extends parallel to the plate member 4 with one end supported by the block member 6. The tube portion at the tip has a branched structure, for example, in a W-shape, in order to increase irradiation efficiency. The block member 6 is attached to the outside of the negative side wall of the light source chamber A, and is exposed to the outside.
A temperature sensor 7 such as a thermocouple is embedded inside the
This sensor 7 is placed in contact with the tube wall of the lamp.

A cooling mechanism 8 for cooling the block member 6 is provided in the vicinity of the block member 6, and the cooling mechanism 8 may be any cooling means such as air cooling or water cooling. Here, in this embodiment, the cooling mechanism 8 has a structure in which the operation is controlled by a control section 9, and a temperature sensor 7 embedded in the block member 6 is connected to the control section 9, and a temperature signal is sent to the control section 9. It is meant to be transmitted.

A processing fluid supply path 10 is formed in the light source chamber A, passing vertically through the center of the light source chamber A, that is, from above the light source chamber A toward the processing chamber B. A processing fluid supply port 11 is formed by opening at the side of the chamber. 'Inside the processing chamber, there is provided a processing stage 12 that can be rotated in a horizontal plane by a rotating means (not shown) such as a motor provided outside the processing chamber A, and the upper surface of this processing stage 12 is The structure is such that a semiconductor wafer 2, which is an object to be processed, is placed with a resist material 3 coated on its upper surface. Incidentally, a heater (not shown) is installed inside the processing stage 12, and the semiconductor wafer 2 placed on the soil surface of the processing stage 12 is heated to a predetermined temperature.

Further, an exhaust port 13 is provided at the bottom of the processing chamber B, so that the inside of the processing chamber B is forcibly evacuated.

Next, the operation of this embodiment will be explained.

When the semiconductor wafer 2 coated with the resist material 3 is placed on the processing stage 12 of the processing chamber B, the processing stage 12
The semiconductor wafer 2 is heated to a predetermined state by the action of a heater (not shown), and the processing stage 12 starts rotating.

Subsequently, the low-pressure mercury lamp 5 in the light source chamber A is turned on, and the semiconductor wafer 2 in the processing chamber B is irradiated with ultraviolet rays. At this time, the processing fluid 14 consisting of oxygen and ozone is started to be supplied to the surface of the semiconductor wafer 2 through the processing fluid supply path 10 and the processing fluid supply port 11.

When the processing fluid 14 thus supplied into the processing chamber B is excited by ultraviolet irradiation, chemically active oxygen radicals O0 are formed, which are applied to the surface of the semiconductor wafer 2. The resist material 3 is oxidized and turned into carbon dioxide gas and water vapor, which are removed from the semiconductor wafer 2 .

The chemical reaction formula of the processing fluid 14 caused by ultraviolet irradiation at this time is as follows.

03→ O, + 02 0 Formula 02→ O1+・0 ■Formula Among the above formulas, the reaction shown by Formula The reaction shown is the reaction caused by the wavelength of 221851 m. Here, in the generation of oxygen radicals ○ and ○, the reaction of formula (■) exclusively contributes, but it is recognized that the reaction of formula (2) also makes a small contribution.

By the way, as mentioned in the "Prior Art" section, it is necessary to control the temperature conditions of the low-pressure mercury lamp 5 to an appropriate temperature in order to make the above reaction most active by ultraviolet irradiation.

Regarding this point, in this embodiment, the coldest point is set in the block member 6, the temperature sensor 7 is embedded in this location, and the control unit 9
Through the control of the cooling mechanism, it is possible to precisely control this coldest point temperature. That is, by controlling the coldest point temperature, it is possible to indirectly control the temperature conditions of the low-pressure mercury lamp 5.

Specifically, the method of controlling the temperature of the low-pressure mercury lamp 5 by controlling the coldest point temperature is as follows.

First, the temperature at the coldest point set as described above and the actual light intensity on the semiconductor wafer 2 are measured, and the light intensity-coldest point temperature characteristic is plotted as shown in FIG. This plot shows, for example, that in this example, oxygen radicals are 0. The ultraviolet wavelength that contributes to the generation of
Two types, 4 nm and λ=1851 m, are performed respectively. The characteristics thus obtained are represented, for example, by the curves (1) and (2) shown in FIG. 2, respectively.

From the light intensity-coldest point temperature characteristic curve obtained in this way, it was found that oxygen radicals were 0. The coldest point temperature (set temperature) that can most efficiently obtain the temperature is stored in the control unit 9.

In this embodiment, the set temperature is, for example, λ-25,
It is desirable to set the temperature to the coldest point temperature Tp+ at which the light intensity P at a wavelength of 41 m has a peak value, or between this TPI and the coldest point temperature T,2 at which the peak value at a wavelength of λ=185 nm. However, this set temperature can be set to a different value depending on the required amount of oxygen radicals.

Further, the set temperature can be changed so that the respective processing efficiency becomes an optimum value depending on, for example, the type of resist material used, the mixing ratio of ozone and oxygen, or the type of processing fluid.

In this way, the temperature condition at the coldest point is determined by the control unit 9
By controlling the operation of the cooling mechanism 8, the set temperature is maintained. Therefore, in this example, it is possible to efficiently generate oxygen radicals ○ by irradiation with ultraviolet rays.

The resist material 3 on the semiconductor wafer 2 is removed by the oxygen radicals 0° generated as described above, and the outline of the reaction for removing the resist in this case is shown by the following equation.

CnHm+O0→nc, 02+%m H2O■ The formation formula is a reaction formula when the structure of the resist material 3 is mainly composed of methylstyrene units.

In this way, the resist material 3 is changed into carbon dioxide gas and water vapor, removed from the surface of the semiconductor wafer 2, and further discharged to the outside of the apparatus through the exhaust port 13.

As described above, according to this embodiment, the following effects can be obtained.

(1) A temperature sensor 7 is embedded in a block member 6 that supports a low-pressure mercury lamp 5, and this block member 6
By controlling the temperature by the cooling mechanism 8 through the control unit 9 based on the signal from the temperature sensor 7, it is possible to maintain the temperature condition of the low-pressure mercury lamp 5 that provides optimal ultraviolet intensity, and the reaction activity is extremely high. Since high oxygen radicals can be efficiently supplied onto the semiconductor wafer 2, the removal efficiency of the resist material 3 can be improved.

(2) By separating the light source chamber A and the processing chamber B with the plate material 4, the chemical reaction of the processing fluid 14 due to ultraviolet irradiation can be caused directly above the semiconductor wafer 2 in the processing chamber B. , it is possible to prevent insufficient supply of oxygen radicals to the resist material 3 on the semiconductor wafer 2.

(3) With the above (1) and (2), it is possible to improve the removal efficiency of the resist material 3, and ultimately improve the manufacturing efficiency of semiconductor devices.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, the processing fluid supply path 10 may be directly connected to the inside of the processing chamber B from the outside of the resist removing apparatus 1 without passing through the light source chamber A.

In the above explanation, the invention made by the present inventor is mainly applied to the field of application, which is a so-called resist removing device, but the present invention is not limited to this, for example, a photo etching device or a photo CVD device.
It can be widely applied to temperature control technology for the lamp itself of other light processing devices such as devices.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

That is, it is an optical processing apparatus that performs processing by irradiating a processing object located in a processing chamber with a predetermined light and supplying a processing fluid that is excited by the predetermined light. The lamp processing device has a structure that includes a temperature sensor embedded in a predetermined part of the lamp, a cooling mechanism that cools the predetermined part, and a control unit that maintains the predetermined part at a set temperature based on a signal from the temperature sensor. By doing this, the temperature conditions of the lamp can be controlled so that the intensity of the predetermined light irradiated from the lamp always maintains the peak value, so that the processing efficiency in lamp processing can be improved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a resist removing apparatus according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the relationship between the coldest point temperature of a low-pressure mercury lamp and the light intensity. 1... Resist removal device, 2... Semiconductor wafer, 3
...Resist material, 4...Plate material, 5...Low pressure mercury lamp, 6...Block member, 7...Temperature sensor, 8
...Cooling mechanism, 9...Control unit, 10...Processing fluid supply path, 11...Processing fluid supply port, 12...Processing stage, 13...Exhaust port, 14...Processing Fluid, A.
...Light source room, B...Processing room.

Claims (1)

[Claims] 1. An optical processing device that performs processing by irradiating a processing object located in a processing chamber with a predetermined light and supplying a processing fluid that is excited by the predetermined light. , a temperature sensor embedded in a predetermined portion of a lamp that irradiates predetermined light, a cooling mechanism that cools the predetermined portion, and a control unit that maintains the predetermined portion at a set temperature based on a signal from the temperature sensor. Light processing equipment. 2. The predetermined portion is the coldest point of the lamp, and the temperature is controlled by the control unit so that the coldest point becomes a temperature condition where the peak intensity of the predetermined light is obtained. The optical processing device according to scope 1. 3. The first aspect of the present invention is characterized in that the lamp and the object to be treated are a low-pressure mercury lamp and a semiconductor wafer whose surface is coated with photoresist, respectively, and the processing fluid is a mixed gas of oxygen and ozone. The optical processing device described in Section 1.