JP2001332712A - Ultraviolet ray irradiation equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize ultraviolet ray irradiation equipment wherein irradiation illuminance can be maintained at a constant level and deterioration of quality and yield of a color filter film and a microlens film which are to be caused by shortage of illuminance can be prevented. SOLUTION: This ultraviolet ray irradiation equipment is provided with a UV lamp 13 which irradiates a resin film arranged on a wafer 15 with ultraviolet ray, a variable voltage power source 17 for supplying a power to the UV lamp 13, and a wafer stage 16 having mechanism for raising and reducing a temperature which holds the wafer. An illuminance monitor 19 for detecting illuminance of irradiation on the wafer 15 and a controller 18 for controlling a power source voltage which is supplied from the variable voltage power source 17 in accordance with the illuminance detected by the illuminance monitor 19 are installed. The controller 18 operates so as to keep illuminance of irradiation from the UV lamp 13 to the wafer 15 at a constant value by controlling a power source voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultraviolet irradiation apparatus, and more particularly to an ultraviolet irradiation apparatus used for curing a color filter film and a microlens film for a solid-state image sensor.

[0002]

2. Description of the Related Art In manufacturing a color filter film and a microlens film of a CCD solid-state imaging device, an ultraviolet irradiation device (UV) is applied to an embossed ultraviolet curable resin or thermosetting resin.
A method of irradiating ultraviolet rays from a curing device to cure the resin and form the resin is used.

FIG. 4 shows a schematic structure of a conventional ultraviolet irradiation apparatus. In FIG. 4, reference numeral 13 denotes a UV lamp, reference numeral 14 denotes a constant voltage power supply, reference numeral 15 denotes a wafer, and reference numeral 16 denotes a wafer stage with a temperature raising / lowering mechanism. The operation of this ultraviolet irradiation device will be described. A wafer 15 placed close to a wafer stage 16 with a temperature raising / lowering mechanism is irradiated with UV light (ultraviolet light) from a UV lamp 13 to which a constant voltage is applied from a constant voltage power supply 14. U
Since the luminous flux of a V lamp or the like changes in proportion to the applied voltage to the power of 3.4 to 3.5, the constant voltage power supply 14 is used as a power supply to suppress the fluctuation of the applied voltage. However, since the UV lamp is a load composed of a lamp exhibiting negative resistance and an inductance, as shown in FIG. 5, the illuminance decreases as the elapsed time after turning on the UV lamp becomes longer. further,
The emission intensity of the UV lamp drops to 80% of the initial value after 1500 hours of use due to a change with time. As described above, there is a change in illuminance and a change with time in the illuminance for each lighting cycle, and the illuminance does not become constant even when the power supply voltage is fixed. Also,
When the UV lamp is used for a long time, there is a problem that the energy applied to the wafer 15 is reduced even if the irradiation time is controlled to be constant.

[0004] When the illuminance of the UV lamp is reduced, curing failure of the ultraviolet curable resin forming the color filter film and the microlens film occurs. If resin curing failure occurs, quality degradation such as molding failure occurs in the microlens film, and in the color filter film, the filter film thickness is poor or curing is not completed sufficiently in the filter dyeing process. The effect appears, causing problems such as color mixing. Therefore, there is a problem in that the quality of the color filter and the microlens and the yield are reduced due to the illuminance of the UV lamp. For example, the deterioration in quality may be caused by a low temperature (-40 ° C to -60 ° C) and a high temperature (+ 100 ° C to +
130 ° C.) can be verified by repeated heat cycle life acceleration tests. In the case of poor quality, cracks 11 in the color filter film, changes in the shape of the microlenses, cracks 12 and the like occur as shown in FIG.

[0005]

As described above, in the conventional ultraviolet irradiating apparatus, curing failure of the ultraviolet curable resin occurs due to a decrease in the illuminance of the UV lamp. There is a problem that the quality of the lens film and the yield are reduced. The present invention solves this problem with a relatively simple configuration, and maintains the illuminance at a constant level, and can prevent the color filter film and the microlens film from deteriorating in quality and yield due to insufficient illuminance. It is an object to realize an irradiation device.

[0006]

In order to achieve the above object, the present invention provides an ultraviolet light source for irradiating a resin film provided on a wafer with ultraviolet light, and a power supply means for supplying power to the ultraviolet light source. And, in an ultraviolet irradiation apparatus having a wafer holding means for holding the wafer,
An illuminance monitor for detecting the illuminance irradiated on the wafer from the ultraviolet irradiation light source, and controlling a power supply voltage supplied by the power supply unit in accordance with the illuminance detected by the illuminance monitor, and Illuminance control means for maintaining the illuminance applied to the wafer at a predetermined value. As a result, it is possible to maintain a constant illuminance applied to the wafer from the ultraviolet irradiating light source, and to realize an ultraviolet irradiating apparatus capable of preventing quality deterioration and a reduction in yield of the color filter film and the microlens film due to insufficient illuminance. can do.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ultraviolet irradiation apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

[0008] The present invention relates to an ultraviolet irradiation apparatus,
In order to prevent a decrease in the quality and yield of the color filter film and the microlens film for the solid-state imaging device caused by a decrease in the illuminance of the lamp, a mechanism for keeping the illuminance constant is provided. In conventional UV irradiators, the power of the UV lamp is a constant voltage system, so the illuminance decreases as the irradiation time elapses after the lamp is turned on, which causes insufficient curing of the color filters and microlenses, resulting in lower quality and yield. Was causing the decline. The present invention relates to an ultraviolet irradiation device for curing a color filter film and a microlens film for a solid-state imaging device, in which color mixing and insufficient curing of a color filter caused by a decrease in illuminance, or quality and yield are reduced due to insufficient curing of a microlens. It was designed to solve the problem.

First, FIG. 1 shows a schematic structural diagram of a solid-state imaging device using a color filter and a microlens. In FIG. 1, reference numeral 1 is a flattening layer, and reference numeral 2
Is a passivation film, 3 is an interlayer insulating film, 4 is a gate insulating film, 5 is a transfer electrode, 6 is a semiconductor substrate, 7 is a color filter (A), 8 is a color filter (B), 9 Is a color filter (C), reference numeral 1
0 is a micro lens.

After forming the flattening layer 1 on the passivation film 2, a color filter (A) is formed by lithography.
7 is formed. Further formed color filter (A)
7 is subjected to an ultraviolet irradiation treatment for curing. The color filter (B) 8 and the color filter (C) 9 are formed in the same manner. After the microlens 10 is also formed by the lithographic method, it is similarly cured by ultraviolet irradiation.

Next, an outline of a constant illuminance type ultraviolet irradiation apparatus of the present invention will be described. FIG. 2 shows a schematic configuration diagram of an embodiment of the constant illuminance type ultraviolet irradiation apparatus of the present invention. In FIG. 2, reference numeral 13 denotes a UV lamp, and reference numeral 15
Reference numeral 16 denotes a wafer stage with a temperature raising / lowering mechanism, reference numeral 17 denotes a variable voltage power supply, reference numeral 18 denotes a controller (voltage control device), and reference numeral 19 denotes an illuminance monitor. For convenience, elements having the same functions as those in FIG. 4 are denoted by the same reference numerals.

A wafer 15 is mounted close to a wafer stage 16 provided with a temperature raising / lowering mechanism for controlling the temperature of the wafer. An illuminance monitor 19 is arranged on the wafer stage 16 with a temperature raising / lowering mechanism. Then, ultraviolet rays (UV light) are emitted from the UV lamp 13 to the wafer 15. At this time, the illuminance of the ultraviolet light is detected by the illuminance monitor 19, and an output signal from the illuminance monitor 19 is taken into the controller 18. The controller 18 adjusts the voltage of the voltage variable power supply 17 so that the illuminance received by the illuminance monitor 19 becomes constant. As a result, as shown in FIG. 3, the illuminance of the UV lamp is kept constant regardless of the elapsed time.

[0013]

As described above, the present invention provides an ultraviolet light source for irradiating a resin film provided on a wafer with ultraviolet light, a power supply for supplying power to the ultraviolet light source, and holding the wafer. In an ultraviolet irradiation apparatus having a wafer holding unit, an illuminance monitor for detecting illuminance irradiated on a wafer from an ultraviolet irradiation light source, and a power supply voltage supplied by a power supply according to the illuminance detected by the illuminance monitor are controlled. And illuminance control means for maintaining the illuminance irradiated on the wafer from the ultraviolet irradiation light source at a predetermined value. According to the present invention, the illuminance of ultraviolet rays emitted from an ultraviolet irradiation (UV cure) device can be kept constant. Therefore, it is possible to prevent a decrease in quality and a decrease in yield due to insufficient curing of the color filter for the solid-state imaging device. Furthermore, color mixing due to insufficient curing can be prevented, and quality deterioration and yield reduction due to color mixing can be prevented. Similarly, it is possible to prevent a decrease in quality and a decrease in yield due to insufficient curing of the microlens for the solid-state imaging device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the structure of a solid-state imaging device to which the present invention is applied.

FIG. 2 is a schematic configuration diagram of a constant illuminance type ultraviolet irradiation apparatus of the present invention.

FIG. 3 is an explanatory diagram showing variations of the illuminance of the UV lamp and the power supply voltage with respect to the elapsed time in the present invention.

FIG. 4 is a schematic configuration diagram of a conventional ultraviolet irradiation device.

FIG. 5 is an explanatory diagram showing variations in illuminance and power supply voltage of a UV lamp in a conventional ultraviolet irradiation device with respect to elapsed time.

FIG. 6 is a cross-sectional view of a solid-state imaging device in which a crack has occurred due to insufficient ultraviolet irradiation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flattening layer, 2 ... Passivation film, 3 ... Interlayer insulating film, 4 ... Gate insulating film, 5 ... Transfer electrode, 6 ... Semiconductor substrate, 7 ... Color filter (A), 8 ... Color filter (B), 9 ... color filter (C), 10 ... micro lens, 11, 12 ... crack, 13 ... UV lamp, 14
... constant voltage power supply, 15 ... wafer, 16 ... wafer stage with temperature raising / lowering mechanism, 17 ... variable voltage power supply, 18 ... controller (voltage control device), 19 ... illuminance monitor.

Claims (1)

[Claims] An ultraviolet irradiation light source for irradiating a resin film provided on a wafer with ultraviolet light; a power supply unit for supplying power to the ultraviolet irradiation light source; and a wafer holding unit for holding the wafer. In the apparatus, illuminance monitoring means for detecting the illuminance irradiated on the wafer from the ultraviolet irradiation light source, and controlling the power supply voltage supplied by the power supply means according to the illuminance detected by the illuminance monitoring means, the ultraviolet irradiation An ultraviolet irradiation apparatus, comprising: illuminance control means for maintaining illuminance irradiated from the light source onto the wafer at a predetermined value.