Embodiments of the present invention relate in general to semiconductor processing systems and in particular to etch systems used to process semiconductor wafers.
With advances in electronic products, semiconductor technology has been widely applied in manufacturing memories, central processing units (CPUs), liquid crystal displays (LCDs), light emission diodes (LEDs), laser diodes and other devices or chip sets. In order to achieve high-integration and high-speed requirements, dimensions of semiconductor integrated circuits have been reduced, and various materials and techniques have been proposed to achieve these requirements and overcome obstacles during manufacturing. In addition to these requirements, manufacturers of semiconductor integrated circuits have imposed requirements of high throughput, high volumes and low down time on equipment used to manufacture their semiconductor integrated circuits.
For example, semiconductor manufacturers have increased wafer dimensions, such as 12-inch wafers, to increase the production of integrated circuits. Manufacturers of integrated circuits also increase the number of facilities or equipment to enhance the number of wafers or chips that are fabricated monthly or annually. In addition, chip manufacturers also modify manufacturing processes to achieve goals of wafer throughputs.
Generally, wafers are subjected to various semiconductor processes, such as thin film depositions, etches, photolithography and thermal treatments. For example, a material layer formed over a wafer is subjected to an etch process by using a photoresist layer as a hard mask. After the etch process, a removing process is carried out to remove the photoresist layer. Then, a cleaning process is performed to remove residues of the photoresist layer or particles over the wafer. The etch process, the photoresist removing process and the cleaning process have different processing times.
Although many, if not all of these different processes, are performed on a single wafer when making an integrated circuit, the processes are often carried out in different tools that have not been configured to operate efficiently between each other. Therefore, what is needed is a system and method for efficiently operating two or more of the processes used to manufacture an integrated circuit so that both processes can produce integrated circuits with high tolerances and still have high throughput and process a high volume of wafers.
According to embodiments of the present invention, a semiconductor processing system includes a factory interface, a central transfer chamber, a first number of etch chambers, and a second number of post-etch treatment chambers. The factory interface is coupled to the transfer chamber and the transfer chamber is coupled to the first number of etch chambers and the second number of post-etch treatment chambers. The first number of etch chambers are configured to etch a substrate at about a first processing time. The second number of post-etch treatment chambers are configured to process the substrate at about a second processing time. The ratio of the first number to the second number is substantially proportional to a ratio of the first processing time to the second processing time.
According to another embodiment of the present invention, the semiconductor processing system further includes at least one robot configured to transfer the substrate between the factory interface and the transfer chamber.
According to the other embodiment of the present invention, a vacuum level within the central transfer chamber is maintained at substantially the same vacuum level as either the etch chambers or the post-etch treatment chambers.
According to an alternative embodiment of the present invention, the first number of etch chambers is 3 and the second number of post-etch treatment chambers is 2.
According to an embodiment of the present invention, the first processing time is between about 75 seconds and about 225 seconds and the second processing time is between about 50 seconds and about 150 seconds.
According to another embodiment of the present invention, the etch chamber are metal etch chambers.
According to the other embodiment of the present invention, the post-etch treatments chambers are configured to remove at least one of photoresist, etch residues and etch by-product.
According to an alternative embodiment of the present invention, the etch chambers are configured to clean the substrate.
According to another embodiment of the present invention, a time for cleaning the substrate is between about 50 seconds and about 150 seconds.
According to other embodiments of the present invention, a semiconductor processing system includes a factory interface, a central transfer chamber, at least one robot, a first number of metal etch chambers, and a second number of post-etch treatment chambers. The factory interface is coupled to the transfer chamber and the transfer chamber is coupled to the first number of metal etch chambers and the second number of post-etch treatment chambers. The at least one robot is configured to transfer a substrate between the factory interface and the transfer chamber. The first number of metal etch chambers are configured to etch a substrate at about a first processing time. The second number of post-etch treatment chambers are configured to process the substrate at about a second processing time. The ratio of the first number of metal etch chambers to the second number post-etch treatment chambers is substantially proportional to a ratio of the first processing time to the second processing time.
According to other embodiments of the present invention, a semiconductor processing system includes a factory interface, a central transfer chamber, at least one robot, three metal etch chambers, and two post-etch treatment chambers. The factory interface is coupled to the transfer chamber and the transfer chamber is coupled to the three metal etch chambers and the two post-etch treatment chambers. The at least one robot is configured to transfer a substrate between the factory interface and the transfer chamber. The three metal etch chambers are configured to etch a substrate at about a first processing time. The two post-etch treatment chambers are configured to process the substrate at about a second processing time. The ratio of the first processing time to the second processing time is approximately 3 to 2.
Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the specification or may be learned by the practice of the invention. The features and advantages of the invention may be realized and attained by means of the instrumentalities, combinations, and methods described in the specification.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings wherein like reference numerals are used throughout the several drawings to refer to similar components. In some instances, a sub-label is associated with a reference numeral and follows a hyphen to denote one of multiple similar components. When reference is made to a reference numeral without specification to an existing sub-label, it is intended to refer to all such multiple similar components.
Semiconductor processing systems are described for achieving a desired process efficiency and/or substrate throughputs.
According to embodiments of the present invention, a semiconductor processing system includes a factory interface, a central transfer chamber, a first number of etch chambers, and a second number of post-etch treatment chambers. The factory interface is coupled to the transfer chamber and the transfer chamber is coupled to the first number of etch chambers and the second number of post-etch treatment chambers. The first number of etch chambers are configured to etch a substrate at about a first processing time. The second number of post-etch treatment chambers are configured to process the substrate at about a second processing time. The ratio of the first number to the second number is substantially proportional to a ratio of the first processing time to the second processing time.
The factory interface 110 is coupled to the central transfer chamber 120. The plurality of etch chambers 130 and the plurality of post-etch treatment chambers 140 are coupled to the central transfer chamber 120. In some embodiments, a vacuum pump (not shown) is coupled to each of the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140. In other embodiments, the temperatures of the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140 are separately controlled. Power to each of the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140 can be individually applied and controlled. A robot is configured to transfer substrates among the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140. In other embodiments, one gate is coupled to each of the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140. The gates are configured to provide access to the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140 by opening or closing. The gates can be individually operated to open and/or close the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140. In some embodiments, one pump is coupled to the central transfer chamber 120, the etch chambers 130 and/or the post-etch treatment chambers 140. However in other embodiments, one pump is coupled to each of the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140. Wafers are transferred between the different chambers where they are undergo several processes, as described in further detail below with reference to
In some embodiments, at least one robot (not shown) can be configured within the factory interface 110 to transfer the substrate 150 among the factory interface 110 and the ports 115. The robot within the factory interface 110 is referred to as a hand-off system.
The substrate 150, which is provided to the semiconductor processing system 100, can vary depending on the application of the invention. For example, if the semiconductor processing system 100 is configured to etch a gate for a transistor, then the substrate 150 maybe a silicon substrate having oxide layer that has undergone nitradation and has a polysilicon layer deposited on top of it. The etch chambers 130 can then be used to etch the gate patterns in the polysilicon layer and the post-etch treatment chambers 140 can then be used to clean the etch residue. Those skilled in the art will realize that there are other applications which include using different incoming substrates 150. For example, substrate 150 could be a silicon substrate, a III-V compound substrate, a silicon/germanium (SiGe) substrate, an epi-substrate, a silicon-on-insulator (SOI) substrate, a display substrate such as a liquid crystal display (LCD), a plasma display, an electro luminescence (EL) lamp display, or a light emitting diode (LED) substrate, for example. In some embodiments, the substrate 150 may be a semiconductor wafer of various sizes (e.g., a 200 mm, 300 mm, 400 mm, etc. silicon wafer).
The central transfer chamber 120, which is coupled to the factory interface 110, is configured so that the substrate 150 can be transferred from the factory interface 110 to the etch chambers 130 or the post-etch treatment chambers 140, or from the etch chambers 130 or the post-etch treatment chambers 140 to the factory interface 110, or from the etch chambers 130 to the post-etch treatment chambers 140, or from the post-etch treatment chambers 140 to the etch chambers 130. Although not shown in
The Etch chambers 130 can be used to etch various materials including metals or dielectrics. If the etch chambers 130 are configured to etch metallic structure formed over the substrate 150, then the etch chamber will be configured to etch materials including, for example, aluminum-containing material such as aluminum, aluminum copper, aluminum silicon copper, other aluminum-containing material or various combinations thereof, tungsten, titanium, titanium nitride; tantalum, tantalum nitride, copper-containing material or other metallic material. The etch chambers 130 can also be configured to etch aluminum-containing metallic layers formed over flash memories, DRAM memories and/or logic circuits. Etching of aluminum-containing materials can be done using halogen-containing etch gasses, such as chlorine. Some examples of etch chambers 130 include AdvantEdge™ etch chambers, decoupled plasma source (DPS™) etch chambers and DPS II™ etch chambers, all of which are commercially available from Applied Materials, Inc., Santa Clara, Calif.
In some embodiments, the post-etch treatment chambers 140 are configured to remove etch residues, etch byproducts and/or photoresist formed for patterning the metallic layer described above. The post-etch treatment chambers 140 may be configured to remove halogen-containing residues, such as chlorine-containing residues and/or photoresist. The post-etch treatment chambers 140 can be referred to as strip and passivation chambers. In some embodiments, the post-etch treatment chambers 140 can include at least one of Axiom™ chambers, Advanced Strip and Passivation (ASP™) and ASP II™ modules, commercially available from Applied Materials, Inc., Santa Clara, Calif.
The system controller 200 is generally designed to facilitate the control and automation of the overall system and typically includes a central processing unit (CPU) (not shown), memory (not shown), and support circuits (or I/O) (not shown). The CPU may be one of any kind of computer processors that are used for controlling various system functions including controlling chamber processes and support hardware (e.g., detectors, robots, motors, gas sources hardware, etc.) or monitoring systems and chamber processes (e.g., chamber temperature, process sequence throughput, chamber process time, I/O signals, etc.). The memory is connected to the CPU, and may be one or more of a readily available memory, such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote. Software instructions and data can be coded and stored within the memory for instructing the CPU. The support circuits are also connected to the CPU for supporting the processor. The support circuits may include cache, power supplies, clock circuits, input/output circuitry, subsystems, and the like. A program (or computer instructions) readable by the system controller 200 determines which tasks are performable on a substrate. Preferably, the program is software readable by the system controller 200 that includes code to perform tasks relating to monitoring, control and execution of the processing sequence tasks and various chamber recipe processes.
In operation, a semiconductor substrate 314 is placed on substrate support pedestal 316 and gaseous components are supplied from a gas panel 338 to DPS chamber 310 through entry ports 326 to form a gaseous mixture 350. Gaseous mixture 350 is ignited into a plasma 352 in DPS chamber 310 by applying RF power from RF sources 318 and 322 respectively to antenna 312 and cathode 316. The pressure within the interior of DPS chamber 310 is controlled using a throttle valve 327 situated between DPS chamber 310 and a vacuum pump 336. The temperature at the surface of chamber walls 330 is controlled using liquid-containing conduits (not shown) that are located in walls 330 of DPS chamber 310.
The temperature of substrate 314 is controlled by stabilizing the temperature of support pedestal 316 and flowing helium gas from a source 348 to channels formed by the back of substrate 314 and grooves (not shown) on the pedestal surface. The helium gas is used to facilitate heat transfer between pedestal 316 and substrate 314. During the etch process, substrate 314 is heated by a resistive heater within the pedestal to a steady state temperature and the helium facilitates uniform heating of substrate 314. Using thermal control of both dome 320 and pedestal 316, substrate 314 is maintained at a temperature of between about 100° C. and about 500° C. Examples of the etch chambers 130 that can be used with exemplary methods of the invention may include those shown and described in co-assigned U.S. Patent Publication No. 2007/0077767 to Jin et al., filed Aug. 14, 2006, and titled “METHOD OF PLASMA ETCHING OF HIGH-K DIELECTRIC MATERIALS,” the entire contents of which is hereby incorporated by reference for all purposes.
Process chamber 402 generally is a vacuum vessel that includes a first portion 410 and a second portion 412, where the first portion 410 includes a substrate pedestal 404, a sidewall 416, and a vacuum pump 414 and the second portion 412 includes a lid 418 and a gas distribution plate (showerhead) 420, which defines a gas mixing volume 422 and a reaction volume 424. Lid 418 and sidewall 416, which are generally formed from a metal (e.g., aluminum (Al), stainless steel, and the like), are electrically coupled to a ground reference 460. Sidewall 416 includes a window 494 (quartz) that is used to monitor the optical emissions within the plasma. Window 494 is coupled to a light-collecting device 492 that carries the optical signals to a optical emission spectroscopy (OES) system 490. Substrate pedestal 404 supports a substrate (wafer) 426 within reaction volume 424. In one embodiment, substrate pedestal 404 can include a source of radiant heat, such as gas-filled lamps 428, as well as an embedded resistive heater 430 and a conduit 432. Conduit 432 provides cooling water from a source 434 to the backside of substrate pedestal 404. Substrate 426 sits on pedestal 404 by gravity or, alternatively, can be mechanically clamped, vacuum clamped, or electrostatically clamped as in an electrostatic chuck. Gas conduction transfers heat from pedestal 404 to substrate 426. The temperature of substrate 426 may be controlled between about 20° C. and about 400° C. Vacuum pump 414, which is used to maintain a desired gas pressure in process chamber 402, as well as evacuate the post-processing gases and other volatile compounds from process chamber 40, is coupled to a throttle valve 438 to control the gas pressure in process chamber 402 and to an exhaust port 436 formed in sidewall 416 of process chamber 402. Process chamber 402 can also include conventional systems for retaining and releasing substrate 426 and internal diagnostics, which are collectively depicted in
Remote plasma source 406 includes a power source 446, a gas panel 444, and a remote plasma chamber 442. In one embodiment, power source 446 includes a radio-frequency (RF) generator 448 capable of producing of about 200 W to about 5000 W at a frequency of about 200 kHz to about 600 kHz, a tuning assembly 450, and an applicator 452 that is inductively coupled to remote plasma chamber 442 and energizes a process gas (or gas mixture) 462 to plasma 464 in the chamber. Gas panel 444, which can include mass flow controllers and shut-off valves to control gas pressure and flow rate, uses a conduit 466 to deliver process gas 462 to the remote plasma chamber 442. Plasma 464, is made up of process gas 462 that have been ionized and dissociated to form reactive species. The reactive species are directed into mixing volume 422 through inlet port 468 in lid 418. To minimize charge-up plasma damage to devices on substrate 426, the ionic species of process gas 462 are substantially neutralized within mixing volume 422 before the gas reaches reaction volume 424 through a plurality of openings 470 in showerhead 420.
Controller 408 includes a central processing unit (CPU) 454, a memory 456, and a support circuit 458. CPU 454 can be a general-purpose computer processor used in an industrial setting and memory 456 can be storage devices such as random access memory, read only memory, floppy or hard disk, or other form of digital storage used to store software routines. Support circuits 458 can include cache, clock circuits, input/output sub-systems, power supplies, and the like.
The window port 494, which is used for attaching light-collecting device 492 (e.g., a fiber optic probe and cable) to monitor plasma intensity, is located slightly above the substrate plane for collecting emission intensity along a line parallel to the substrate. Optical emission spectroscopy hardware 490, used to analyze the plasma and process is coupled to the window port 494.
Referring again to
It is noted that the first and second processing times and the numbers of the etch chambers 130 and the post-etch treatment chambers 140 are not limited to the exemplary embodiments described above. Various ratios of the first processing time to the second processing time can be used. Other ratios, processing times and numbers of the etch chambers 130 and the post-etch treatment chambers 140 can be applied in other embodiments. One of ordinary skill in the art, based on the exemplary embodiments set forth above, can modify the ratio to achieve a desired manufacturing throughput.
In some embodiments, the etch chambers 130 may be configured to clean the substrate 150 before and/or after the etch process. The cleaning process may have a processing time between about 10 seconds and about 60 seconds. In one specific embodiment, the cleaning process may have a processing time of about 30 seconds. In some embodiments, a time for transferring the substrate 150 between the etch chambers 130 and the central transfer chamber 120 can be between about 10 seconds and 20 seconds. In one specific embodiments, a time for transferring the substrate 150 between the etch chambers 130 and the central transfer chamber 120 can be about 5 seconds. In some embodiments, a time for transferring the substrate 150 between the post-etch treatment chambers 140 and the central transfer chamber 120 can be between about 5 seconds and about 20 seconds. In one specific embodiment, a time for transferring the substrate 150 between the post-etch treatment chambers 140 and the central transfer chamber 120 can be about 10 seconds.
The central transfer chamber 120 may have a level of vacuum that is substantially equal to at least one of the etch chambers 130 and the post-etch treatment chambers 140. With the substantially similar vacuum among the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140, the pumping process for substantially equalizing the pressures within the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140 may be saved. By removing the pumping time the throughput is increased. In some embodiments, the substrate 150 is transferred between the central transfer chamber 120, the etch chambers 130 and the post-etch treatment chambers 140, which have substantially similar vacuum levels, such that the substrate 150 is not exposed to the atmosphere. The issue of corrosion and/or contamination of the substrate 150 due to the exposure may be desirably avoided.
Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. Additionally, a number of well known processes and elements have not been described in order to avoid unnecessarily obscuring the present invention. Accordingly, the above description should not be taken as limiting the scope of the invention.
Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.
As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a method” includes a plurality of such methods and reference to “the precursor” includes reference to one or more precursors and equivalents thereof known to those skilled in the art, and so forth.
Also, the words “comprise,” “comprising”, “include”, “including”, and “includes” when used in this specification and in the following claims are intended to specify the presence of stated features, integers, components, or processes, but they do not preclude the presence or addition of one or more other features, integers, components, processes, acts, or groups.
The present application claims benefit under 35 USC 119(e) of U.S. provisional Application No. 60/992,283 filed on Dec. 4, 2007, entitled “Etch System,” the content of which is incorporated herein by reference in its entirety. This application is related to co-assigned U.S. Patent Publication No. 2006/0289384 to Pavel et al, filed Aug. 28, 2006, and entitled “METHOD AND APPARATUS FOR PERFORMING HYDROGEN OPTICAL EMISSION ENDPOINT DETECTION FOR PHOTORESIST STRIP AND RESIDUE REMOVAL.” This application is also related to co-assigned U.S. Patent Publication No. 2007/0077767 to Jin et al., filed Aug. 14, 2006, and titled “METHOD OF PLASMA ETCHING OF HIGH-K DIELECTRIC MATERIALS.” The entire contents of both related applications are hereby incorporated by reference for all purposes.
Number | Date | Country | |
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60992283 | Dec 2007 | US |