Coating apparatus – Gas or vapor deposition – With treating means
Reexamination Certificate
1999-11-15
2001-10-16
Mills, Gregory (Department: 1763)
Coating apparatus
Gas or vapor deposition
With treating means
C118S712000, C118S715000, C118S719000
Reexamination Certificate
active
06302966
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to fabrication of semiconductor integrated circuits and, more particularly, to temperature control of plasma processing systems.
2. Description of the Related Art
In the fabrication of semiconductor-based devices, e.g., integrated circuits or flat panel displays, layers of materials may alternately be deposited onto and etched from a substrate surface. During the fabrication process, various layers of material, e.g., borophosphosilicate glass (BPSG), polysilicon, metal, etc. are deposited on the substrate. The deposited layers may be patterned with known techniques, e.g., a photoresist process. Thereafter, portions of the deposited layers can be etched away to form various features, e.g., interconnect lines, vias, trenches, and etc.
The process of etching may be accomplished by a variety of known techniques, including plasma-enhanced etching. In plasma-enhanced etching, the actual etching typically takes place inside a plasma processing chamber. To form the desired pattern on the substrate wafer surface, an appropriate mask (e.g., a photoresist mask) is typically provided. With the substrate wafer in the plasma processing chamber, a plasma is then formed from suitable etchant source gas (or gases). The plasma is used to etch areas that are left unprotected by the mask, thereby forming the desired pattern. In this manner, portions of deposited layers are etched away to form interconnect lines, vias, trenches, and other features. The deposition and etching processes may be repeated until the desired circuit is obtained.
To facilitate discussion,
FIG. 1
depicts a simplified plasma processing apparatus
100
suitable for fabrication of semiconductor-based devices. The simplified plasma processing apparatus
100
includes a plasma processing chamber
102
having an electrostatic chuck (ESC) or other wafer support
104
. The chuck
104
acts as an electrode and supports a wafer
106
(i.e., substrate) during fabrication. The surface of the wafer
106
is etched by an appropriate etchant source gas that is released into the wafer processing chamber
102
. The etchant source gas can be released through a showerhead
108
. The plasma processing source gas may also be released by other mechanisms such as through holes in a gas distribution plate. A vacuum plate
110
maintains a sealed contact with walls
112
of the wafer processing chamber
102
. Coils
114
provided on the vacuum plate
110
are coupled to a radio frequency (RF) power source (not shown) and used to strike (ignite) a plasma from the plasma processing source gas released through the showerhead
108
. The chuck
104
is also typically RF powered during the etch processes using a RF power supply (not shown). A pump
116
is also included to draw the process gases and gaseous products from the plasma processing chamber
102
through a duct
118
.
As is known by those skilled in the art, in the case of semiconductor processing, such as etch processes, a number of parameters within the wafer processing chamber need to be tightly controlled to maintain high tolerance results. The temperature of the wafer processing chamber is one such parameter. Since the etch tolerance (and resulting semiconductor-based device performance) can be highly sensitive to temperature fluctuations of components in the system, accurate control therefore is required. To further elaborate, the chamber temperature at which etching processes are performed needs to be tightly controlled to achieve desirable etch characteristics. Moreover, as feature sizes of modern integrated circuits continue to be reduced, it becomes increasingly more difficult to process the desired features using conventional plasma processing systems.
In plasma processing apparatus, plasma formed by excited process gasses is used to manufacture semiconductor devices, the excitation of the process gasses to produce the plasma is a high energy operation that causes heating of various components of the plasma processing apparatus. This heating effects the precision and repeatability of the processes performed by the plasma processing device. As feature sizes continue to get smaller, there is an ever increasing need to provide plasma processing apparatus with better temperature control in order to provide consistent and precise fabrication of semiconductor devices.
Conventionally, heating has been provided to plasma processing chambers by providing the plasma processing chambers with heated inner walls or by heating the plasma processing chamber using small heat lamps. Heating is typically used to pre-heat the plasma processing chamber before processing begins. Cooling was often not actively provided, thus cooling was simply passive through convection and radiation. Typically, these thermal solutions were designed for aluminum liners of plasma processing chambers and thus are not well suited for heating or cooling ceramic liners which is a more difficult task. Aluminum lines also lead to significant contamination which is why ceramic liners are considered.
In view of foregoing, there is a need for improved plasma processing systems that provide better temperature control over semiconductor processing equipment.
SUMMARY OF THE INVENTION
Broadly speaking, the invention pertains to a temperature management system and method that can achieve very accurate temperature control over a plasma processing apparatus. In one embodiment, the temperature management system and method operate to achieve tight temperature control over surfaces of a plasma processing apparatus which interact with the plasma during fabrication of semiconductor devices. The tight temperature control offered by the invention provides greater process control for the plasma processing apparatus which is becoming more and more important as feature sizes continue to get smaller.
The invention can be implemented in numerous ways, including as a system, apparatus, machine, or method. Several embodiments of the invention are discussed below.
As a plasma processing apparatus, one embodiment of the invention includes at least: a processing chamber having walls and a lid, the walls and the lid both have an internal surface and an exterior surface, the processing chamber being used to process a substrate using a plasma produced by process gases; and a thermal management system thermally coupled to an exterior surface of the processing chamber, the thermal management system including at least one combination heating and cooling block that is controlled to regulate a temperature internal to the processing chamber.
As a semiconductor manufacturing apparatus, one embodiment of the invention includes at least: a plasma processing chamber formed by walls and a bottom surface; a sealing lid removably coupled to a top portion of the walls of the plasma processing chamber; an RF powered electrode provided on an upper surface of the sealing lid; at least one temperature sensor coupled to the sealing lid or the plasma processing chamber; a first heating and cooling unit coupled to the upper surface of the sealing lid; and a second heating and cooling unit coupled to an outer surface of the walls of the plasma processing chamber.
As a method for providing temperature control to a plasma processing chamber of a plasma processing apparatus, the method includes at least the acts of: directly or indirectly measuring temperature internal to the plasma processing chamber; comparing the measured temperature to a target temperature; heating the plasma processing chamber by heating a thermal control block that is thermally coupled to the plasma processing chamber; and cooling the plasma processing chamber by actively cooling the thermal control block.
As a plasma processing apparatus, another embodiment of the invention includes at least: a processing chamber having walls and a lid, the walls and the lid both have an internal surface and an exterior surface, the processing chamber being used to process a substrate using a plasma produced by process gases; and means for
Bailey III Andrew D.
Kuthi Andras
Schoepp Alan M.
Smith Michael G. R.
Beyer Weaver & Thomas LLP
Lam Research Corporation
Mills Gregory
Zerrigon Rudy
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