JP2785696B2 - High-power low-pressure mercury lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short wavelength ultraviolet light source for photochemical reactions such as light ashing and light cleaning.

[0002]

2. Description of the Related Art As a short wavelength ultraviolet lamp, a pair of electrodes is provided at both ends of a discharge tube made of fused silica glass or synthetic quartz glass that transmits short wavelength ultraviolet light, and mercury and a starting gas are contained in the discharge tube. And the mercury vapor pressure is discharged at a low pressure to reduce the mercury vapor pressure to 185 nm and 25%.
Low-pressure mercury lamps that emit 4 nm resonance lines are often used. These lamps have recently been ashing, light cleaning,
It is used in the fields of semiconductors, liquid crystal panels, etc. for surface modification.

In these fields, a high-output low-pressure mercury lamp is required to increase the processing speed. A low-pressure mercury lamp is used because the mercury vapor discharge becomes 185 nm at high pressure,
This is because the resonance line of 54 nm self-absorbs, and therefore, it is necessary to keep the mercury vapor pressure at a low pressure in order to efficiently emit the resonance line.

Therefore, the output of the resonance line is increased by increasing the electric input to the lamp to increase the output, and forcibly cooling part of the lamp wall to control the mercury vapor pressure in the tube to a low pressure. A high-power low-pressure mercury lamp, which is dramatically improved compared to conventional lamps, can be realized. Such high-output low-pressure mercury lamps have been put into practical use in various systems, for example, a system in which a metal block is mounted near an electrode and cooled directly or indirectly is known.

[0005] Lamps used for the purpose of light cleaning and light ashing are often turned on in a closed container whose atmosphere in a clean room is controlled. The conventional high-power low-pressure mercury lamp has a shape in which the discharge part and the electrode part are flush with each other, so that an area larger than the sum of the discharge part and the electrode part of the lamp is required, and the floor area of the apparatus becomes large. There was a problem. In particular, it is not preferable to install the apparatus in a vacuum chamber or in an apparatus in which a vacuum state is temporarily established at the time of gas replacement because the apparatus becomes extremely large.

SUMMARY OF THE INVENTION The present invention has been made in view of such a background, and has as its object to provide a high-power type lamp having a devised lamp shape and configuration in order to provide an irradiation apparatus having stable performance and a reduced floor area. It is to provide a low-pressure mercury lamp.

[0007]

A high-power low-pressure mercury lamp according to the present invention has a shape in which a discharge portion approximated to a surface light source and an electrode portion containing a pair of electrodes are arranged on a plane parallel to each other. A structure is provided in which a heat insulating member or a heat / ultraviolet reflecting member is mounted in the space between the discharge part and the electrode part, and a part of the electrode part is forcibly cooled.

[0008]

By arranging the electrode section on the upper side of the discharge section and arranging it in parallel, the floor area of the irradiating device is reduced, and radiation is provided by mounting a heat insulating member or a heat reflecting member in the space between the electrode section and the discharge section. Efficiency and life performance are stable.

[0009] By directly or indirectly water-cooling a part of the tube wall of the electrode portion, it is possible to increase the output of the low-pressure mercury lamp. As a result, the conventional low-pressure mercury lamp is 1 W / cm
Although it was possible to light only at a low output level of less than 1, a high output of 1 W / cm or more can be achieved in the present invention.

[0010]

FIG. 1 is a front view and a plan view of a lamp used in an embodiment of the present invention. The discharge part 1 of the lamp was made of synthetic quartz glass, and a discharge tube having a tube diameter of 20 mm and a length of 2000 mm was bent to form a 240 mm × 240 mm square planar shape. An appropriate amount of mercury and argon as a starting gas are sealed in the discharge tube.

At both ends of the discharge section 1, there are electrode sections 2 accommodating a pair of electrodes 3 for discharge. The electrode part 2 and the discharge part 1 are connected by a connection part 4. In the lamp of the present invention, the connecting portion 4 has a bent shape so that the discharge portion 1 and the electrode portion 2 are in a parallel position.

The cooling section comprises a metal block 5 made of aluminum, a metal plate 6, a water cooling block 7 made of stainless steel, and the like. A metal block 5 is provided on a part of the tube wall of the electrode unit 2.
And a metal member structured to be sandwiched and fixed by the metal plate 6. The metal block 5 is in contact with the water cooling block 7 to indirectly cool a part of the tube wall of the electrode unit. Such a lamp is turned on with a power of 670 W, but is controlled by the cooled metal block 5 so that the temperature of the mercury condensing section in the discharge tube becomes an optimum value, thereby realizing a high-output low-pressure mercury lamp.

When the electrode portion 2 is bent and disposed above the discharge portion 1, the metal block portion is heated by the heat generated from the discharge portion 1. It is considered that the mercury vapor pressure in the tube becomes higher than the optimum value due to the influence, and the radiation efficiency of the mercury resonance line radiated from the discharge unit 1 decreases. Therefore, in the present invention, by arranging a heat reflecting plate 8 made of aluminum or the like between the electrode unit 2 and the discharge unit 1, an adverse effect due to heat generated in the discharge unit 1 is effectively prevented. Table 1 shows comparison data on the intensity of the ultraviolet light of 254 nm and the temperature of the mercury condensing part in the presence or absence of the heat reflection plate.

[0014]

[Table 1] In the configuration of the present invention in which the heat reflecting plate is mounted, the temperature of the mercury condensing section is reduced by 20 degrees and the ultraviolet intensity is increased about twice as compared with the case without the heat reflecting plate.

The same applies when a heat insulating member such as glass wool or gypsum is interposed in the space between the electrode portion 2 and the discharge portion 1 in place of the heat reflecting plate 8 to prevent the transfer of heat. Has the effect of

[0016]

As described above, according to the present invention, a compact high-output low-pressure mercury lamp can be obtained, and an economical apparatus having a high processing speed and a small floor area of an irradiation apparatus can be realized in the field of light cleaning and light ashing. it can.

[Brief description of the drawings]

FIG. 1 is a schematic view (a front view and a plan view) showing an embodiment of the lamp of the present invention.

[Description of Signs] 1 Discharge part 2 Electrode part 3 Electrode 4 Connecting part 5 Metal block 6 Metal plate 7 Water cooling block 8 Heat reflection plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 61/067 H01J 61/32

Claims (1)

(57) [Claims] 1. A high-power low-pressure mercury lamp that lights at 1 Watt of power per emission length 1 cm, the discharge portion on the pseudo plan light source and so as to flush the discharge tube straight tube An electrode part in which a pair of electrodes are accommodated is disposed in a position parallel to the discharge part; and a heat insulating member or a heat and ultraviolet reflection member is provided between the discharge part and the electrode part. A high-output low-pressure mercury lamp comprising a cooling unit for directly or indirectly water-cooling a part of an electrode unit.