Wet-etching facility for manufacturing semiconductor devices

Details Wet-etching facility for manufacturing semiconductor devices Wet-etching facility for manufacturing semiconductor devices

1999-09-28

2001-05-22

Lund, Jeffrie R. (Department: 1763)

Adhesive bonding and miscellaneous chemical manufacture

Differential fluid etching apparatus

With microwave gas energizing means

C134S001300, C216S088000, C216S085000, C216S089000

Reexamination Certificate

active

06235147

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wet-etching facility for manufacturing semiconductor devices, and more particularly, to a wet-etching facility for manufacturing semiconductor devices for easily removing the impurities with the used surface of the wafer faced down.
2. Description of the Related Art
Generally, the etching process in the semiconductor devices fabrication processes is a process to selectively remove the most upper layer of the wafer through a photo resist layer having a certain pattern after exposure and development, etc. Normally, a wet-etching or dry-etching method can be used.
The wet-etching process is performed by immersing the wafer into a bath having a certain amount of chemical disposed therein, and causing a chemical reaction with a contacted surface of the wafer so that the unnecessary portion of the wafer is etched by the chemical.
FIG. 1
shows a conventional wet-etching facility to perform the wet-etching process in the semiconductor devices fabrication process.
As shown in
FIG. 1
, the conventional wet-etching facility comprises a box-shaped bath
110
storing a chemical
3
therein, a chemical supply part (not shown) to supply the chemical
3
to the bath
110
through a chemical opening
110
a
formed on the bottom of the bath
110
, a chemical container
120
to collect the chemical
3
overflowing over the bath
110
, a chemical discharge part (not shown) to discharge the chemical
3
collected in the chemical container
120
to the outside through a discharge opening
120
a
formed on the bottom of the chemical container
120
, and a wafer guide
130
to fix the wafer
1
to the slots
130
a
having a plurality of wafers
1
vertically fit thereinto, the slot
130
a
aligned with a constant interval, and to place them the wafers
1
into the chemical
3
using a suitable device, such as a robot arm
136
.
In the conventional wet-etching facility having a construction as above, the chemical supply part supplies the chemical
3
such that the chemical
3
overflows out of the bath
110
via the chemical opening
110
a
formed on the bottom of the bath
110
, and the flow of the chemical
3
is formed on the surface of the wafer
1
so as to facilitate the chemical reaction between the chemical and the wafer
1
.
However, as shown in
FIG. 2
, since the used surface of the wafer
1
is placed vertically, and the etched impurities
2
of the wafer
1
by the chemical cannot be completely removed therefrom resulting in an amount of etched impurities
2
accumulating on the bottom of the etch groove by gravity. This accumulation of etched impurities
2
is one of the main reasons why a malfunction may occur in the following process and also results in inferior wafers being generated due to the impurities being attached on the used surface of another wafer.
In addition, since the plurality of wafers
1
are vertically aligned inside the slots, there is a possibility that on occasion the upper end of one wafer
1
touches the other wafers, and they are broken since the wafers are shaken during the transfer.
In addition, since a plurality of wafers
1
are horizontally loaded during a transfer, there is required an extra wafer vertical-aligning apparatus to vertically rotate the wafers when the wafers are converted to be into a vertical state. Therefore, the facility is complicated, and productivity is decreased because of the time waste by the wafer vertical-aligning.
In addition, since the bath is box-shaped, and the flow of the chemical is directed from the lower side to the upper side, as anti-gravity direction, particle vortex occurs inside the bath, particularly, on the corners therein or maintenance of chemical thereby resulting in difficulty of the uniform process for wafers.
SUMMARY OF THE INVENTION
The present invention is directed to provide a wet-etching facility for manufacturing semiconductor devices, which obviates one or more of the problems due to the limitation and the disadvantages of the related art.
One object of the present invention is to provide a wet-etching facility for manufacturing semiconductor devices, wherein the etching process is performed for a wafer with its used surface faced down so that the by-products from the etching process are completely removed from the etching groove of the wafer by gravity, and the impurities on the back side of the wafer sink down, and do not touch the used surface of the other wafer thereby producing good quality of wafers.
Another object of the present invention is to provide a wet-etching facility for manufacturing semiconductor devices, wherein the loading/unloading of the wafers can be done with horizontally laid wafers, the wafers are stably stayed during their transfer, and an extra facility is not necessary for vertically aligning the wafers thereby resulting in increased the productivity.
The other object of the present invention is to provide a wet-ething facility for manufacturing semiconductor devices, wherein the shape of the bath is cylindrical, and the flow of the chemical is directed from the upper side to the lower side to be matched with the direction of gravity, so as to prevent the appearance from occurring partial vortex inside the bath or forming a stagnation area of chemical thereby resulting in the uniform process for wafers.
To achieve these and other advantages and in accordance with the purpose of the present invention, the wet-etching facility for manufacturing semiconductor devices comprises a bath containing an amount of chemical; a chemical supply part for supplying an amount of chemical to the bath; a chemical discharge part for discharging the chemical inside the bath to the outside; a wafer guide for holding and fixing a wafer with its used surface facing down, and placing the wafer into a chemical; a transfer robot for loading and unloading the wafer into the wafer guide; and a chemical spray part for spraying the chemical with a high pressure such that the chemical flows along the surface of the wafer.
The chemical supply part and the chemical discharge part are connected via a circulation line including a filter, a pump, and a heater such that some of the chemical discharged from the chemical discharge part, passes through according to the open/close of the valve, and is collected and circulated into the chemical supply part.
The wafer guide comprises left and right moving members having a plurality of slots contacted with the edge of each of the plurality of wafers horizontally held between the slots; and a cylinder installed between the left and right moving members, and extending/contracting the pistons connected with the left/right moving members to control the distance between the left moving member and the right moving member.
The chemical spray part comprises a plurality of nozzles installed on each of the wafers to spray chemical horizontally to the wafers with a high pressure; and a chemical spray line having a plurality of nozzles on its end, and being connected with the chemical supply part to supply chemical to the nozzles.
In addition, the wet-etching facility further comprises a wafer guide rotation apparatus for rotating the wafer guide to rotate the wafer by transmitting the rotation force of the motor to the wafer guide by a driving force transfer apparatus, and further comprises a cleaning solution supply part for supplying the cleaning solution in the bath or the chemical spray part to clean the wafer and the bath, or the chemical dicharge part and the chemical spray part.
In addition, the wet-etching facility for manufacturing semiconductor devices further comprises a cassette stage having a cassette mounted thereon, a plurality of wafers loaded on the cassette; and a wafer aligning apparatus for aligning the plurality of wafers loaded on the cassette on a buffer part so as to face down the used surface of the wafer and align them in a constant interval.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and ex

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