Adhesive bonding and miscellaneous chemical manufacture – Differential fluid etching apparatus – With radio frequency antenna or inductive coil gas...
Reexamination Certificate
2001-12-06
2004-12-21
Hassanzadeh, Parviz (Department: 1763)
Adhesive bonding and miscellaneous chemical manufacture
Differential fluid etching apparatus
With radio frequency antenna or inductive coil gas...
C156S345300, C118S7230IR, C118S715000
Reexamination Certificate
active
06833050
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for manufacturing a semiconductor device, and more particularly, to an apparatus for manufacturing a semiconductor device with improved uniformity of plasma density.
2. Description of the Related Art
Apparatuses for manufacturing semiconductor devices can be classified as an apparatus for forming a thin film on a semiconductor substrate, an apparatus for performing a photolithography process to form a mask pattern on the thin film to form fine patterns, an apparatus for etching the thin film using the mask pattern as an etching mask to form fine patterns, and an apparatus for implanting impurity ions into the semiconductor substrate. As the line width of patterns is reduced due to increased integration density of semiconductor devices, the quality and capabilities of etching apparatuses and deposition apparatuses used for forming fine patterns become more important. Etching apparatuses are typically classified as either dry etching apparatuses, such as plasma etching apparatuses, and wet etching apparatuses. As the integration density of semiconductor devices increases, dry etching apparatuses, which enable anisotropic etching to be performed, are typically used, and apparatuses adopting a chemical vapor deposition method using plasma, e.g., plasma-enhanced chemical vapor deposition (PE-CVD), are used as deposition apparatuses.
FIGS. 1A and 1B
show two-dimensional views of apparatuses for manufacturing a semiconductor device according to the prior art.
FIG. 1A
shows an induced coupled plasma etching apparatus
10
having a dielectric plane structure, and
FIG. 1B
shows an induced coupled plasma etching apparatus
40
having a dielectric dome structure. For illustrative convenience, it is considered that chambers
12
and
42
are cylindrical, lower electrodes
26
and
56
are circular plates, an insulating plate
20
shown in
FIG. 1A
is circular, and an insulating plate
50
shown in
FIG. 1B
is dome-shaped. A plurality of induction coils
14
shown in
FIG. 1A
for generating a plasma source span a distance that is substantially equal to the diameter L1 of the insulating plate
20
. Similarly, a plurality of induction coils
44
shown in
FIG. 1B
span a distance that is substantially equal to the length of curved surface of the insulating plate
50
. The insulating plate
20
and the lower electrode
26
shown in
FIG. 1A
have almost the same diameters L1 and L2, and the projected diameter L4 of the curved surface of the insulting plate
50
shown in
FIG. 1B
is designed to be substantially equal to the diameter L5 of the lower electrode
56
. The diameters of wafers
30
and
60
supported by static chucks
28
and
58
that are mounted on the lower electrodes
26
and
56
are designed to be smaller than the diameters of the lower electrodes
26
and
56
. Confinement layers
22
and
52
, which confine plasma regions
24
,
54
a
, and
54
b
, are designed to contact the edges of the insulating plates
20
and
50
and extend in a direction that is perpendicular to the lower electrodes
26
and
56
.
Referring to
FIGS. 1A and 1B
, insulating layers or conductive layers are deposited on the wafers
30
and
60
and then etched to obtain desired patterns.
A low-frequency power supplied from first power supplies
16
and
46
is applied to a plurality of induction coils
14
and
44
to generate a magnetic flux. Inductance of coils
14
and
44
creates an electric field and a magnetic field in a plasma region
24
,
54
a
, and
54
b
via the insulating plates
20
and
50
included in the chambers
12
and
42
. Here, a high-frequency external power is supplied to the lower electrodes
26
and
56
via second power supplies
18
and
48
. Electrons move due to the magnetic field and the electric field in the plasma regions
24
,
54
a
, and
54
b
and are accelerated to bombard a reactive gas to generate reactive ions of plasma. The reactive ions are diffused/absorbed into objects to be etched on the wafers
30
and
60
.
Since plasma (or reactive ions) is incident to the center of the wafers
30
and
60
and diffused into the sides of the wafers
30
and
60
, plasma density at the center of the wafers
30
and
60
is higher than plasma density at the edge of the wafers
30
and
60
. Thus, since a large amount of plasma is incident to the center of wafers
30
and
60
, patterns positioned at the center of the wafers
30
and
60
are over-etched. Since a small amount of reactive ions is diffused/absorbed at the edge of the wafers
30
and
60
, patterns positioned at the edge of the wafers
30
and
60
are under-etched. Since the under-etched or over-etched patterns can greatly affect a subsequent process and/or the characteristics of the semiconductor device, it is important to maintain uniformity of etching throughout a wafer.
The above-described non-uniformity of plasma density occurs in deposition apparatuses as well as etching apparatuses. The thickness of a pattern formed at the edge of a wafer is thinner than the thickness of a pattern formed at the center of the wafer, and thus uniformity of the patterns is not ensured.
In order to meet semiconductor users' demand for high added value as well as low price, the price of semiconductor devices is typically lowered by manufacturing a large number of chips in a single process, i.e., using large diameter of wafers. Wafers having a diameter of 200 mm are typically used for producing most advanced semiconductor devices, such as memories and logics. However, it is expected that semiconductor devices will soon be mass-produced using wafers having diameters of 300 mm.
The differences in plasma density at different locations on a wafer becomes more pronounced for such larger-diameter wafers. A variety of techniques for correcting non-uniformity of plasma density have been proposed for wafers having a diameter of 200 mm, but these fail to adequately ensure etching uniformity and deposition uniformity when processing wafers having a diameter of 300 mm. Further, since plasma density is low at the edge of wafers, etch rate or deposition rate necessary for forming patterns at the edge of the wafers according to a design is not typically attained.
Accordingly, the semiconductor industry requires a technique by which a high plasma density region is formed on a wafer having a large diameter (i.e. over 200 mm and 300 mm) in order to obtain uniform etching and/or deposition throughout the wafer.
SUMMARY OF THE INVENTION
To solve the above-described problems, it is a feature of the present invention to provide an apparatus for manufacturing a semiconductor device with improved uniformity of plasma density throughout.
It is another feature of the present invention to provide an apparatus for manufacturing a semiconductor device having improved effective plasma density.
Accordingly, there is provided an apparatus for manufacturing a semiconductor device using plasma. The apparatus includes a chamber for performing a manufacturing process on the semiconductor device under a plasma atmosphere and a device installed in the chamber for concentrating the plasma. The device reduces the size of a plasma region near an object to be processed as compared to the size of a plasma region near a part of the chamber where the plasma is generated. The device for concentrating the plasma includes: a lower electrode having a first length on which the object to be processed is positioned; an insulating plate having a second length that is longer than the first length and that is separated from and facing the lower electrode; and a confinement layer contacting the edge of the insulating plate, forming an acute angle to a virtual plane connecting opposing ends of the insulating plate, and extending toward the edge of the lower electrode. The diameter of the circular plate is the first length if the lower electrode is a circular plate. Here, the acute angle is preferably 45-89 degrees.
In more detail, the insulating plate includes a first pa
Hong Jin
Jeon Jeong-sic
LandOfFree
Apparatus for manufacturing semiconductor device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for manufacturing semiconductor device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for manufacturing semiconductor device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3331337