JPH0356045Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultraviolet irradiation device, and more particularly to an ultraviolet irradiation device that can maintain the lamp temperature at an appropriate temperature.

In the semiconductor manufacturing process, ultraviolet irradiation is used to deposit oxide films on substrates using photochemical vapor deposition, and to decompose and clean organic dirt adhering to the surface as a preliminary cleaning process. is attracting attention for its use in baking processes. This baking process is a photosensitive process in which, for example, a semiconductor wafer on which an oxide film or the like is deposited and a photosensitizer coated thereon is exposed to light to partially remove the photosensitizer, and the area from which the photosensitizer has been removed. A heating process that is inserted between the etching process that removes the oxide film and forms a pattern, and bakes at a temperature of about 120 to 200 degrees Celsius for the purpose of improving the adhesive strength of the oxide film, etc. Regarding the process, it is preferable that the temperature is higher as this improves the adhesive strength. However, if this temperature is set to 140° C. or higher, the surface and vertical planes of the photosensitive agent become distorted, resulting in poor patterns and poor performance. Therefore, by irradiating the semiconductor wafer with ultraviolet light before the baking process, the baking temperature can be lowered.
It is known that the adhesive strength can be improved even at temperatures above 140°C without deteriorating the pattern. However, it has become clear that the effective wavelength range for ultraviolet light is 200 to 300 nm.

By the way, recently, semiconductor wafers have become larger,
Ultraviolet lamps with a diameter of 4 inches (approximately 102 mm) or more are now being manufactured, and with this trend, the ultraviolet lamps used also tend to have larger capacities.
Furthermore, as the size of the UV lamp increases, the demand for increasing the amount of UV light generated relative to the input power increases. In order to improve the efficiency of UV irradiation, it is necessary to control the temperature of the lamp's coldest point to an appropriate temperature, but it is also important that the light emitting part is not overcooled by means of cooling the coldest point. It is.

Therefore, the purpose of the present invention is to provide an ultraviolet irradiation device with a simple structure that can control the coldest spot position and the light emitting part of the ultraviolet lamp to an appropriate temperature, and has high ultraviolet irradiation efficiency. , the light emitting part of the ultraviolet lamp is protruded from the front of the mirror, and a cooling means is provided that can air-cool the bulb part that surrounds the electrode part of the lamp located at the back of the mirror and the back of the mirror, so that the bulb part surrounding the electrode part is The temperature difference between the temperature at the cold spot position and the light emitting part is set to be 10°C or more, and the temperature at the coldest spot position is maintained at 20 to 30°C.

The present invention will be specifically described below based on embodiments shown in the drawings.

A mirror 2 is arranged horizontally in the substantially center of the device box 1, and a vertical sub-mirror 3 is arranged below the periphery to form a box shape. The ultraviolet lamp 4 is arranged such that its light emitting part 4a is in a space surrounded by the mirror 2 and the sub-mirror 3, and the bulb part 4b surrounding the electrode part is located above the back of the mirror 2. This ultraviolet lamp 4 has an arc length of
Although it is a low-pressure mercury lamp that is over 100 cm long and mainly emits ultraviolet light with a wavelength of 254 nm, the bulb part 4b surrounding the electrode part is arranged in a vertical position, and the light emitting part 4a
is bent in a meandering substantially W-shape to form a horizontal surface light source. A front glass 5 made of quartz glass is provided below the light emitting section 4a, and ultraviolet rays from the ultraviolet lamp 4 are transmitted through the front glass 5 and irradiated downward. The semiconductor wafer which is the object 6 to be irradiated is a large one with a diameter of 6 inches (approximately 153 mm), and is supported by a support 9 approximately 2.5 cm below the light emitting section 4a.

Next, a cooling fan 7 is provided on the top surface of the device box 1, and the cooling air is guided by a duct 8 to the valve part 4b surrounding the electrode part through the back surface of the mirror 2, and the temperature at the coldest point position is control. Since the light emitting part 4a protrudes downward from the surface of the mirror 2, the cooling air is not directly directed to the light emitting part 4a.
does not apply.

When the semiconductor wafer that has undergone the exposure process is supported in the above position, the cooling fan 7 is operated, and the ultraviolet lamp 4 is turned on, the wavelength of 254 nm is mainly detected.
UV rays are irradiated onto the semiconductor wafer. At this time, since the cooling air is guided to the valve part 4b surrounding the electrode part, the temperature at the coldest point position in this vicinity is controlled to 20 to 30°C. Since the light emitting section 4a is not directly exposed to the cooling air, the temperature is increased to 40 to 60 degrees Celsius. Therefore, the ultraviolet lamp 4 most efficiently generates ultraviolet light with a wavelength of 254 nm. Next, the semiconductor wafer that has undergone this irradiation process is baked at a temperature of 180°C, and even though the baking temperature was as high as 180°C, the entire surface and vertical planes were not distorted over a wide area. I was able to obtain a good pattern.

As explained above, the present invention provides an ultraviolet irradiation device that can efficiently generate ultraviolet light with a wavelength of 254 nm by controlling the temperature of the coldest point of the ultraviolet lamp and the temperature of the light emitting part to the optimum temperature. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of an embodiment of the present invention, and FIG. 2 is a side sectional view thereof. 1... Equipment box, 2... Mirror, 3... Secondary mirror, 4... Ultraviolet lamp, 4a... Light emitting part, 4b
...Bulb part surrounding the electrode part, 5...Front glass, 6...Irradiated object (semiconductor wafer), 7...
Cooling fan, 8... duct.

Claims (1)

[Scope of utility model registration request] The light emitting part of the ultraviolet lamp is protruded from the front of the mirror, and a cooling means is provided that can air-cool the bulb part that surrounds the electrode part of the lamp located at the back of the mirror and the back of the mirror. Make sure that the temperature difference between the cold spot position and the light emitting part is 10℃ or more, and also keep the temperature at the coldest spot position
An ultraviolet irradiation device that is maintained at a temperature of 20 to 30°C.