Optics: measuring and testing – Inspection of flaws or impurities – Surface condition
Reexamination Certificate
2002-12-30
2004-12-28
Toatley, Jr., Gregory J. (Department: 2877)
Optics: measuring and testing
Inspection of flaws or impurities
Surface condition
C356S237100, C356S244000, C250S372000
Reexamination Certificate
active
06836322
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a particle inspection device and an inspection method using the same, and more particularly, to a particle inspection device and an inspection method using the same which can inspect both a wafer and a photomask using a scattering type inspection device since the scattering of a laser light irradiated from a light source can be avoided by fabricating a multi-use holder in a wafer shape, providing a second mounting portion and a first mounting portion on the upper surface thereof and forming a coating portion on the upper surface of the multi-use holder thereon when disposing the multi-use holder on a chuck fixed to a supporter by a vacuum generator, thereby reducing costs and improving productivity.
2. Description of the Related Art
Defects generated in a semiconductor device during manufacturing must be inspected and removed before product is shipped so as to increase the quality and yield of the product. Currently, process induced defect inspection devices are classified into (1) wafer process inspection devices and (2) photo mask process inspection devices and LCD inspection devices.
Additionally, inspection devices adapted to an algorithm, which are mainly used for a wafer, include a defect inspection device using a pattern-to-pattern comparison method and a database inspection device commonly adapted to photomasks, LCD's, and the like. Besides, a die-to-die inspection device adapted to a wafer and a photomask is included. Typically, the database inspection takes much longer than the pattern-to-pattern inspection and the die-to-die inspection. In the database inspection of a photomask with a design rule of 0.15 &mgr;m level, it takes about two hours.
Generally, the photomask is a light transmitting quartz. Thus a technical method of inspecting defects on the photomask provides that the defects on the photomask are discriminated from normal chrome patterns or phase shift materials by analyzing information of reflectance light and transmittance light on the upper surface of the photomask.
On the contrary, since a method of inspecting defects on a wafer uses a non-transparent silicon substrate, it inspects defects only with reflectance light (reflectance method).
A method of inspecting a wafer mainly inspects defects using a laser light incident at an inclination. In some cases, the wafer is disposed on a chuck with a stage and is adsorbed and fixed by a vacuum. Then, a laser light is irradiated at an inclination from the side surface and then light scattered on a defective portion is detected. Next, whether a defect exits or not is determined by comparison with adjacent patterns (scattering method)
FIG. 1
is a schematic view showing the construction of a conventional particle inspection device. The construction of the particle inspection device for inspecting particles of a wafer will now be described. The particle inspection device includes: a wafer
5
with a chrome pattern
4
on an upper surface; a chuck
6
supporting the bottom of the wafer
5
; a vacuum conduit
7
for supplying a vacuum pressure into the chuck
6
to adsorb and fix the wafer
5
thereon; a stage
8
supporting the bottom of the chuck
6
via a supporter; a light source
2
irradiating a laser light on the wafer
5
at an inclinational angle; and a CCD camera
1
receiving and analyzing the laser light irradiated from the light source
2
when it is reflected from a defective portion
3
.
The operational state of the particle inspection device will be described. The wafer formed with a chrome pattern is mounted on the chuck
6
and is fixed by applying a vacuum pressure via the vacuum conduit
7
.
In this state, a laser light is irradiated from the light source
2
and is reflected onto the defective portion
3
. Then, the light incidents on the CCD camera
1
and detects a defect by analysis and by comparison with other patterns.
However, the above-described scattering method is only used for inspection of a non-light transmitting wafer. This scattering method is advantageous in that it takes much shorter time than the reflectance method.
In contrast, the reflectance method is mainly adapted to materials causing scattering with clear fields such as a photomask. But, it takes much more time for analysis, and this causes lower productivity.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a particle inspection device and an inspection method using the same which can inspect both a wafer and a photomask using a scattering type inspection device since the scattering of laser light irradiated from a light source can be avoided by fabricating the multi-use holder in a wafer shape, providing a second mounting portion and a first mounting portion on the upper surface thereof and forming a coating portion on the upper surface of the multi-use holder thereon when disposing the multi-use holder on a chuck fixed to a supporter by a vacuum generator, thereby reducing the cost and improving productivity.
In accordance with an aspect of the present invention, there is provided a particle inspection device, comprising: a multi-use holder being provided with a first mounting portion and a second mounting portion on which the wafer and the photomask each having a chrome pattern on the upper surface are selectively mounted; a tray supporting the bottom surface of the multi-use holder; a chuck adsorbing and fixing the tray by vacuum; a supporter provided with a vacuum conduit and supporting the chuck; a vacuum generator supplying a vacuum pressure to the chuck via the vacuum conduit; a stage having the vacuum generator disposed thereon and horizontally moving the tray by means of the supporter; and a CCD camera receiving and analyzing a laser light irradiated from a light source disposed on the wafer at an inclination and reflected from a defective portion.
In accordance with another aspect of the present invention, there is provided a particle inspection device for inspecting particles of a wafer and a photomask, having: a chuck adsorbing and fixing an object mounted on the upper surface by vacuum; a supporter being provided with a vacuum conduit and supporting the chuck; a vacuum generator supplying a vacuum pressure to the chuck via the vacuum conduit; a stage having the vacuum generator disposed thereon and horizontally moving the tray by means of the supporter; and a CCD camera receiving and analyzing a laser light irradiated from a light source disposed on the wafer at an inclination and reflected from a defective portion, wherein the particle inspection device comprises a multi-use holder provided with a first mounting portion and a second mounting portion on which the wafer and the photomask each having a chrome pattern on the upper surface are selectively mounted and fixed by the chuck.
In accordance with yet another aspect of the present invention, there is provided an inspection method using a multi-use holder of a particle inspection device of a scattering type, comprising the steps of: mounting a photomask onto the multi-use holder provided with a first mounting portion for mounting a wafer and a second mounting portion for mounting a photomask; inserting a fixing material made of rubber into an insertion hole formed at a corner and forcedly fixing the same so as to prevent the photomask from being movable; mounting the multi-use holder having the photomask mounted thereon on a tray and adsorbing and fixing the same by applying vacuum to a chuck via a vacuum conduit from a vacuum generator; and analyzing a defect by a CCD camera after receiving the light scattered on a defective portion of the photomask, that is, the laser light irradiated from a light source.
In accordance with still another aspect of the present invention, there is provided an inspection method using a multi-use holder of a particle inspection device of a scattering type, comprising the steps of: mounting a wafer onto the multi-use holder provided with a first mounting portion for mounting a wafer and a sec
Hynix / Semiconductor Inc.
Marshall, Gerstein and Borun LLP
Nguyen Sang H.
Toatley , Jr. Gregory J.
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