Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2002-05-02
2004-08-17
Webb, Gregory (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C134S902000, C134S030000, C134S002000, C134S025300, C134S026000
Reexamination Certificate
active
06777379
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cleaning solution and a method of cleaning an anti-reflective coating (ARC) composition using the same and, more particularly, to a method of cleaning accumulated and cured ARC compositions remaining on semiconductor manufacturing equipment.
2. Description of the Related Arts
Recently, as digital information has become more widely adopted, the use of computers has become widely spread. With increasing amounts of digital information becoming available and with the growing need to process greater amounts of digital information, there is an ever-growing demand and requirement placed on semiconductor devices for faster operating speeds as well as for handing and processing greater amounts of digital data. In order to satisfy these requirements, manufacturing methods for semiconductor devices have been developed to increase the degree of integration, increase reliability and increase processing and response time. In order to increase the degree of integration in semiconductor devices, efforts have been and are being made towards reducing the cell size and margin of all of the patterns formed on a semiconductor substrate. On the other hand, a vertical size of semiconductor devices, that is, an aspect ratio of each element making up the semiconductor device, has increased.
Current day semiconductor devices generally include a transistor structure with appropriate doping regions, a capacitor, and an electrical interconnection pattern to connect these various components. The manufacture of current day semiconductor devices requires a multitude of process steps, including photolithography, doping, etching and thin film deposition. Among these process steps, one of the most important areas of semiconductor manufacturing process that has enabled high levels of semiconductor device integration is photolithography.
Photolithography is a basic process that is essential to current day semiconductor fabrication. Every semiconductor device requires at least several photolithography processes to form desired circuit patterns as mandated by its design. As the design of semiconductor devices dictate higher levels of integration, the role of photolithography becomes more important.
Photolithography may be used for patterning a semiconductor substrate, a metal layer, an insulating layer, etc. in the manufacture of an integrated circuit of a semiconductor device. Although the technical details of how photolithography is carried out are complex, the theory of photolithography is relatively easy to describe.
In order to form a pattern using photolithography, a photoresist film or layer is formed on a device wafer surface to be patterned, such as on an insulating layer or a conductive layer on a substrate. The photoresist film or layer may be made of an organic compound, the solubility of which to an alkaline solution changes after exposure to a light source, e.g., ultraviolet (UV) light or an X-ray. The photoresist film or layer is exposed by a light source through a photomask having a pattern to be transferred onto the device wafer surface. The photoresist film is then developed to remove those portions of the photoresist film having a high solubility (i.e., exposed portions for a positive type photoresist), while remaining portions having a low solubility (i.e., unexposed portions for a positive type photoresist) form a photoresist pattern. Layers underlying the photoresist pattern are then etched using the photoresist pattern as an etching mask, and thereafter the photoresist pattern may be removed to obtain a pattern used in forming conductive patterns, wiring, electrodes, as well as other components of a semiconductor device. However, as the level of integration increases and the size of devices become smaller, the photoresist compound used for the photolithography process poses various problems. One of these problems relates to diffused reflection during exposure of a photoresist layer. To address this problem, an organic anti-reflecting coating (“AR”) process has been employed to minimize diffused reflection.
As described above, photolithography is used to form a pattern of an underlying layer using a photoresist onto which an optical phase can be formed. The optical phase corresponds to a transferring pattern to be formed on the underlying layer. After exposure and development of the photoresist film, the photoresist pattern is formed. However, as the size of semiconductor devices become smaller, e.g., to the degree of 0.35 microns or less, the wavelength of the light used for the exposure becomes shorter. Accordingly, the degree of reflection and scattering of light at the underlying layer increases with undesired exposure characteristics. For example, the undesired exposure might change the channel depth (CD) of small size devices.
In order to address the above-described problem, an ARC layer is formed between the photoresist film and the underlying layer. The thickness of the ARC layer is formed to be about 1000 Å or less. Accordingly, the ARC layer is very thin when compared with that of the photoresist film. In order to pattern the underlying layer after developing the photoresist film, the exposed ARC layer also should be removed.
The ARC layer is generally formed from a composition including a polyimide-based compound, a polyacrylate-based compound, and other like compounds. The thickness of the ARC layer is a function of its refractive index; however, the ARC layer is generally formed to a thickness between about 400-600 Å. The function of the ARC layer is to reduce a refractive coefficient of the exposure light during photolithography to reduce undesired exposure characteristics at the underlying layer due to reflection of the exposure light.
FIG. 1
is a cross-sectional, schematic view of an equipment for coating a photoresist or an organic ARC composition on a semiconductor wafer.
The equipment includes an outer container
10
having a cover at the upper portion thereof, and an inner container
60
containing a spin chuck
20
for supporting a wafer W. The spin chuck
20
is operatively coupled to a drive
30
through a bottom portion of the outer container
10
to rotate the wafer W which is fixed at the upper portion of the spin chuck
20
.
The outer container
10
may have the same configuration as the inner container
60
. The upper portion of the outer container
10
is maintained at a predetermined distance from the spin chuck
20
in order to prevent spattering of an organic material such as a photoresist material to the outer portion of the outer container
10
during a coating process of the organic material. A nozzle
40
for coating an organic material and a side rinse nozzle
50
are provided at the upper portion of the outer container
10
. The nozzles
40
and
50
are movable towards and away from the plane of the wafer W.
The inner container
60
is installed at the inner portion of the outer container
10
to prevent spattering of organic materials such as photoresist compounds to the outer container
10
. The inner container
60
is manufactured using a material having heat-resistance, scratch-resistance and low viscous properties. That is, the inner container
60
is comprised of TEFLON, PP (polypropylene), etc. The inner container
60
is periodically detached for a cleaning.
The wafer W positioned on the spin chuck
20
is fixed by vacuum through the spin chuck
20
. The nozzle for coating organic material
40
moves downwardly and closer to the wafer W, and then the organic material is coated on the wafer W. At the same time, the spin chuck
20
driven by a driver
30
rotates at a constant velocity and the organic material coated on the surface of the wafer spreads out uniformly by a centrifugal force.
A rinsing solution supplied from the side rinse nozzle
50
removes organic material fixed at the edge portion of the wafer. After completing the rinsing operation, the rinsing solution is exhausted out through an exhausting pipe
70
provided through a bottom po
Chung Hoi-Sik
Jun Pil-Kwon
Kim Kyung-Dae
Kim Young-Ho
Park Dong-Jin
Lee & Sterba, P.C.
Samsung Electronics Co,. Ltd.
Webb Gregory
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