JPH07130608A - Aligner - Google Patents

Abstract

PURPOSE:To uniform integrated exposure quantity by satisfying, during exposure, a specified equation with respect to the irradiation time of pulse light, the scanning speed of a first object, and exposure distance of the pulse light on the first object. CONSTITUTION:An aligner irradiates a first object (mask) which is scanned in one direction with a plurality of pulse lights, and projects the first object on a second object (wafer) which is scanned together with the first object. When the irradiation period of the pulse light is T, the scanning speed of the first object in the direction is V, and the width (exposure distance) of the pulse light concerning the direction on the object is L, the aligner is so constituted as to satisfy L=NXVXT (N is an integer) during exposure. Thereby the variation of integrated exposure quantity at any position can be eliminated, and a semiconductor device of high integration level can be manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus, and more particularly to I
C, semiconductor devices such as LSI, liquid crystal panel, CCD,
The present invention relates to a scanning type exposure apparatus used for manufacturing various devices such as a magnetic head.

[0002]

2. Description of the Related Art Conventionally, a mask and a wafer are scanned in a certain direction with a projection optical system sandwiched by an ultraviolet beam continuously emitted by an ultra-high pressure mercury lamp or the like, and each pattern of the mask is scanned. 2. Description of the Related Art A scanning type exposure apparatus is known in which portions are sequentially projected onto a wafer.

[0003]

When a pulsed light radiation source such as an excimer laser is used instead of a lamp in this scanning type exposure apparatus, as shown in FIG. 2, each pulsed light is integrated with a certain width. As a result, the exposure amount on the mask or wafer cannot be made uniform in the scanning direction.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure apparatus capable of making the integrated exposure amount uniform.

In order to achieve this object, the exposure apparatus of the present invention irradiates a first object (mask) which is scanning in a certain direction with a plurality of pulsed lights, and a second object which is scanning together with the first object.
An object (wafer) is projected, and the irradiation period of the pulsed light is T, the scanning speed of the first object in the direction is V, and the pulsed light is directed on the first object. When the width (exposure distance) is L, L = N × V × T (N is an integer) is satisfied during exposure.

In particular, the exposure apparatus of the present invention starts irradiation with the pulsed light from a position at least a distance L before the pattern of the first object, and moves the pattern of the first object at least a distance L away. Therefore, the irradiation of the pulsed light is stopped.

In order to satisfy the above conditions, the width of the opening in the scanning direction of the masking blade for limiting the illumination area by the pulsed light on the first object is changed, or the first and second
Change the scanning speed of the object.

By using the exposure apparatus of the present invention, I
C, semiconductor devices such as LSI, liquid crystal panel, CCD,
Various devices such as a magnetic head can be manufactured accurately.

[0009]

1 is a schematic view showing a first embodiment of the present invention, showing a scanning type exposure apparatus for manufacturing devices such as semiconductor devices, liquid crystal panels, CCDs and magnetic heads.

In FIG. 1, 1 is a laser light source that oscillates pulsed light, 3 is an optical integrator, and a lens 2 is used to provide a light source 1 and an optical integrator 3.
The light incident surface 3a has a relationship between the image and the pupil. A masking blade 5 limits the irradiation range of the pulsed light on the reticle 21, and is movable in a single axis direction. The lens 6 forms an image of the slit-shaped opening of the masking blade 5 on the exposed surface 7. Reference numeral 8 denotes a projection optical system, which reduces and projects the image of the pattern arranged on the exposed surface 7 onto the exposed surface 9. Reference numeral 10 is a folding mirror.

The device pattern of the reticle 21 is arranged on the surface 7 to be exposed, and the reticle 21 is held by an XY stage which can move in two directions perpendicular to the optical axis of the system. Two
A wafer 2 is arranged so that its upper surface is aligned with the surface 9 to be exposed, and is held by an XY stage which can be moved in two directions perpendicular to the optical axis of the system. During exposure, the reticle 21 and the wafer 22 are scanned by the XY stages in the left-right direction in the drawing.

The light passing through the opening of the masking blade 5 reflects the opening shape of the masking blade on the surface 7 to be exposed to form a rectangular illumination area. FIG. 2 shows how the reticle 21 and the wafer 22 are sequentially exposed to pulsed light in accordance with the pulse oscillation of the light source 1 while the reticle 21 and the wafer 22 are moving in the short side direction of the rectangle in this region. At this time, the wafer 22 moves in the direction opposite to the moving direction of the reticle 21 (if the reticle on the paper surface of FIG. 1 is in the right direction (X direction), the wafer moves in the left direction (−X direction), and the speed is m times ( The magnification of the projection lens 8 is m.).

When the reticle 21 is continuously moved and intermittently irradiated with pulsed light for exposure,
As shown in FIG. 2, the exposure area is shifted by the shift amount ΔX. When the cycle of the pulsed light is T and the moving speed of the reticle is V, ΔX = V × T ... (1), and the exposure of the pulsed light is integrated while being shifted by ΔX.

FIG. 3 shows the relationship between the integrated exposure amount and the scan in the X direction. The horizontal axis of FIG. 3 indicates the X coordinate of the reticle 21. FIG. 6 is a diagram showing an integrated exposure amount at the time t = 0 when the exposure of the first pulse starts, and thereafter, as time passes by the pulse period T.

In FIG. 3, between the exposure distances L'and .DELTA.X limited by the masking blade, L '= N.times..DELTA.X (N is an integer) ... (2) = N.times.V.times.T. There is.

Now, it is assumed that the scan speed and the oscillation cycle of the pulsed light are fixed. When the width of the masking blade is adjusted to control the exposure distance L ′ which is an integral multiple of (V × T), the exposure field exposed by one pulse becomes
Assuming that the illuminance distribution is always uniform, the integrated exposure amount becomes uniform near the center of the reticle 21, but it is clear from FIG. 3 that illuminance unevenness occurs at the start and end of exposure, but this range is the exposure distance L ′. Therefore, if the exposure is started from the front by L ′ and the end is delayed by L ′, the reticle 21 and the wafer 2 can be used even if a pulsed light emission type illumination source is used.
The entire pattern surface of No. 2 can be exposed evenly in the integrated exposure amount.

On the other hand, assuming that the equation (2) does not hold, as shown in FIG. 4, at the time of the exposure of the last pulsed light in the exposure field, one block that was uniformly exposed until then is the field. Since it is divided into an inner part and a part outside the field, unevenness of the integrated exposure amount for one pulse exposure occurs.

The projection optical system 9 may be either a refraction system or a reflection system.

In the above-mentioned embodiment, the exposure distance is changed by the masking blade to satisfy the equation (2), but the scanning speed may be controlled instead of the exposure distance. This corresponds to controlling the moving speed of the reticle 21 and the wafer 22 in the apparatus of FIG. The distribution of the integrated exposure amount at this time is shown in FIG. Change the amount of movement for each pulse,
By controlling the moving speeds of the reticle 21 and the wafer 22 so as to satisfy the expression (1), unevenness of the integrated exposure amount for one pulse can be suppressed.

Instead of controlling the scan speed, the pulse period may be changed to satisfy the formula (1).

Next, an embodiment of a method of manufacturing a semiconductor device using the above exposure apparatus will be described. FIG. 6 shows a flow of manufacturing a semiconductor device (semiconductor chip such as IC or LSI, or liquid crystal panel, CCD or the like). In step 1 (circuit design), the circuit of the semiconductor device is designed. In step 2 (mask manufacturing), a mask having the designed circuit pattern is manufactured. On the other hand, step 3 (wafer manufacture)
Then, a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by the lithography technique using the mask and the wafer prepared above. Next step 5
(Assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer manufactured in Step 4, and an assembly process (dicing, bonding),
It includes steps such as packaging (chip encapsulation). In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 7).

FIG. 7 shows a detailed flow of the wafer process. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), electrodes are formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted in the wafer. Step 15
In (resist processing), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is printed and exposed on the wafer by the exposure apparatus described above. In step 17 (development), the exposed wafer is developed. In step 18 (etching), parts other than the developed resist image are removed. In step 19 (resist stripping), the resist that is no longer needed after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

By using the manufacturing method of this embodiment, it is possible to manufacture a highly integrated semiconductor device which has been difficult to manufacture in the past.

[0024]

As described above, according to the present invention, even if pulsed light is used as the illumination light of the scanning type exposure apparatus, it is possible to eliminate the unevenness of the integrated exposure amount depending on the location.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

FIG. 2 is a schematic view showing a device for limiting illumination light and an exposure area on a surface to be exposed.

FIG. 3 is an explanatory diagram showing a case where the integrated exposure amount is uneven.

FIG. 4 is an explanatory diagram showing a case where an integrated exposure amount is uniform.

FIG. 5 is an explanatory diagram showing a case where an integrated exposure amount is uniform.

FIG. 6 is a diagram showing a manufacturing flow of a semiconductor device.

FIG. 7 is a diagram showing the wafer process of FIG. 6;

[Explanation of symbols]

 1 light source 2 lens 3 optical integrator 4 lens 5 masking blade 6 lens 7 exposed surface 8 projection optical system 9 exposure surface 10 folding mirror 21 reticle 22 wafer

Claims (2)

[Claims] 1. A first object, which is scanning in a certain direction, is irradiated with a plurality of pulsed light, and the first object is scanned by the plurality of pulsed light onto a second object, which is scanning in the direction.
In an exposure apparatus that projects a pattern of an object, the irradiation period of the pulsed light is T, the scanning speed of the first object in the direction is V, and the width of the pulsed light on the first object in the direction is L. Then, during the exposure, the exposure apparatus is set to satisfy L = N × V × T (N is an integer). 2. The irradiation with the pulsed light is started from the front of the pattern of the first object by at least the distance L, and the irradiation of the pulsed light is stopped at the position at least the distance L of the pattern of the first object. The exposure apparatus according to claim 1, wherein: