Universal lithographic tool

Abstract

A lithographic apparatus (50) having a controller (55), an exposure system (66, 67), and a wafer loader system (94) is disclosed. The controller (55) is operable to configure and directly control the exposure system (66, 67), the wafer loader system (94), and at least one of: an inspection system (72) and a resist processing system (82). The exposure system may have an LED illumination source (66) configurable to emit G-line, H-line, and / or i-line radiation, and a controller (55) operable to configure and directly control the LED illumination source (66) to select and cause emission of G-line, H-line, or i-line radiation.

Description

Technical Field

[0001] This invention generally relates to the field of semiconductor manufacturing. More specifically, this invention belongs to the field of semiconductor lithography equipment. This invention also relates to computer programs and computer program products for configuring and controlling lithography equipment. Background Technology

[0002] In a conventional semiconductor manufacturing facility (fabs), photolithography typically uses four separate systems: a stepper for exposure, an inspection tool, a coating tool, and a developing tool.

[0003] Such an arrangement makes it impossible to perform all photolithography steps, process wafers of any size, and expose at any wavelength in a single tool.

[0004] Semiconductor manufacturers need to purchase a variety of tools to implement a given process, and then purchase more equipment as their process changes.

[0005] Mercury arc lamps are used as lighting sources in conventional stepper motors, but they are difficult to configure, expensive to operate, and have a relatively short service life. Summary of the Invention

[0006] A lithography apparatus substantially as shown in at least one of the accompanying drawings and / or described in combination with at least one of the accompanying drawings and as set forth more fully in the claims.

[0007] According to a first aspect of the present invention, a photolithography apparatus is provided, the photolithography apparatus comprising:

[0008] - Controller;

[0009] - Exposure system; and

[0010] -Chip loader system

[0011] The controller is operable to configure and directly control the exposure system, the wafer loader system, and at least one of the following:

[0012] - Inspection system; and

[0013] - Resist treatment system.

[0014] Preferably, the photolithography equipment further includes an inspection system.

[0015] Preferably, the photolithography equipment further includes a resist treatment system.

[0016] Preferably, the exposure system includes an LED illumination source configurable to emit G-line, H-line, and / or i-line radiation, and the controller is operable to configure and directly control the LED illumination source to select and emit G-line, H-line, or i-line radiation.

[0017] Preferably, the wafer loader system includes a pre-aligner and a carrier plate configured to receive wafers of multiple nominal diameters.

[0018] Preferably, the lithography apparatus further includes a machine vision system operable as a camera for the alignment system of the exposure system and as a camera for the inspection system.

[0019] Preferably, the resist treatment system includes a coater, an oven, and a developer, and the processor is operable to configure and directly control the coater, the oven, and the developer.

[0020] Preferably, the wafer loader system includes a wafer ID reader, and the processor is operable to configure and directly control the exposure system based on readings from the wafer ID reader.

[0021] According to a second aspect of the invention, a computer program is provided that includes computer-readable instructions, which, when executed on a suitable computer device, cause a controller to configure and directly control at least one of the exposure system, wafer loader system, inspection system, and resist treatment system according to the first aspect.

[0022] According to a third aspect of the present invention, a computer program product comprising the computer program of the second aspect is provided. Attached Figure Description

[0023] The desired outcome is a tool that can be configured for any photolithography process.

[0024] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0025] Figure 1 A schematic diagram illustrates a conventional lithography equipment line.

[0026] Figure 2 A photolithography apparatus according to an embodiment of the present invention is illustrated in schematic form. Detailed Implementation

[0027] The following description contains specific information relating to embodiments of the invention. Those skilled in the art will recognize that the invention can be practiced in ways other than those specifically discussed herein. Furthermore, some specific details of the invention have not been discussed to avoid obscuring its meaning.

[0028] The accompanying drawings and detailed descriptions in this application are only for exemplary embodiments of the invention. For the sake of brevity, other embodiments of the invention are not specifically described in this application and are not specifically illustrated by means of the accompanying drawings.

[0029] Embodiments of the present invention may provide a centralized tool that is modular and configurable to perform multiple photolithography processes within a single piece of equipment:

[0030] • Coated wafers

[0031] Align the target on the chip

[0032] • Expose the wafer to GHI or i-ray radiation

[0033] • Develop the wafer

[0034] • Inspect the completed printed pattern

[0035] This tool can process wafers of any standard size.

[0036] refer to Figure 1 The illustration shows a lithography equipment line with four separate systems (tools). The stepper 10 includes a stepping system 12 and a dedicated stepper controller 15 running its own discrete software. The stepping system has its own wafer input indexer 13 and wafer output indexer 14. The stepping system 12 has an exposure system including a mercury lamp illumination source 16 configured to emit G-line, H-line, or i-line radiation (G / H / i). The stepping system also has an alignment system 18 for aligning the pattern formed by radiation projection through a mask with a pattern on the exposed wafer.

[0037] Inspection tool 20 includes inspection system 22 and dedicated inspection controller 25 running its own discrete software. Inspection system 22 has its own wafer input indexer 23 and wafer output indexer 24. Inspection system 22 has one or more inspection cameras 26 for imaging features on the wafer, such as for measuring critical dimensions (CD).

[0038] The coating tool 30 includes a coating system 32 and a dedicated coating controller 35 running its own discrete software. The coating system 32 has its own wafer input indexer 33 and wafer output indexer 34. The coating system 32 has a coater 36 and an oven 37 for coating the resist onto the wafer and baking or curing the resist.

[0039] The developing tool 40 includes a developing system 42 and a dedicated coating controller 45 running its own discrete software. The developing system has its own wafer input indexer 43 and wafer output indexer 44. The developing system 42 has a developing machine 48 for developing patterns that have been exposed in the resist.

[0040] refer to Figure 2The lithography equipment 50 includes a controller 55, exposure systems 66 and 67, and a robotic wafer loader system 94. The controller 55 is operable to configure and directly control the exposure systems 66 and 67, the wafer loader system 94, and at least one of the following: an inspection system 72 and a resist treatment system 82. The controller 55 is operable to configure the systems, for example, by setting operating parameters or selecting specific operations for the respective systems. In other words, the controller does not simply initiate the operation of each system at a high level, but rather control is performed by a separate controller for each respective system.

[0041] In this example, the lithography apparatus 50 includes an inspection system 72 and a resist treatment system 82. However, these systems may be missing from lithography apparatuses, and this embodiment allows for the easy addition and control of these systems.

[0042] The exposure system includes an LED (light-emitting diode) illumination source 66 configurable to emit G-line, H-line, and / or i-line radiation, and a controller 55 operable to configure and directly control the LED illumination source 66 to select and emit G-line, H-line, and / or i-line radiation. The i-line radiation wavelength is approximately 355 nm, the H-line is approximately 405 nm, and the G-line is approximately 435 nm. A green alignment LED 57 with a wavelength of approximately 520 nm is provided.

[0043] The wafer loader system includes a pre-aligner and a carrier plate configured to receive multiple wafers of nominal diameter (e.g., 150 mm, 200 mm, or 300 mm).

[0044] The machine vision system 92 is operable as a camera for the alignment system 68 of the exposure systems 66 and 67, and as a camera for the inspection system 72. The MVS is a camera with software that is mounted on both the stepping system and the inspection system, and its optics make it suitable for both systems.

[0045] The resist treatment system 82 includes a coater 86, an oven 87, and a developer 88, and the processor is operable to directly control the coater 86, the oven 87, and the developer 88.

[0046] The wafer loader system 94 includes a wafer ID (identifier) ​​reader 99, and the processor is operable to configure and directly control the exposure system based on the readings of the wafer ID reader 99.

[0047] In this example, computer program 58 is loaded into a computer within controller 55. Computer program 58 has computer-readable instructions that, when executed on a suitable computer device (such as the device embedded in the controller in this example), cause controller 55 to configure and directly control at least one of the exposure systems 66 and 67, the wafer loader system 94, and the inspection system 72 and the resist treatment system 82 as described above.

[0048] A computer program product 59 storing computer program 58 is shown.

[0049] refer to Figure 2 The described lithography equipment 50 only has a modular, non-application-specific controller 55 / software 58 and a robotic wafer loader 94, instead of Figure 1 The four different tools shown are 10, 20, 30, and 40.

[0050] In addition, refer to Figure 2 The described photolithography apparatus 50 has an LED illumination source 66 instead of a mercury arc lamp illumination source 16 for exposing wafers on a corresponding stepper system. The LED illumination source 66 has three switchable wavelengths (G-line / H-line / i-line). The illumination can be selected from G-line, H-line, i-line wavelengths or any combination thereof.

[0051] The controller 55 uses application-independent software, allowing it to control various lithography systems. In this example, the controller controls:

[0052] - Machine vision system (MVS) pattern recognition system 92, which is used for alignment of stepping system 62 and for inspection system 72;

[0053] - LED power supply 66 for the stepper in the exposure system;

[0054] - Process equipment for coating machine 86 and developing machine 88; and

[0055] - A general-purpose robotic chip loader system 94, used for system-controlled chip manipulation, such as... Figure 2 The lines in the diagram are shown.

[0056] The advantage of this embodiment is that the entire lithography equipment line can be easily integrated into a single piece of equipment. Another advantage of this embodiment is that exposure using LEDs on the stepper can be switched from G-line or H-line to i-line.

[0057] It also has advantages in terms of system / equipment savings. (See reference) Figure 1 In the described conventional lithography facility, the system will use:

[0058] 1. A total of four controllers / software units: 15, 25, 35, and 45.

[0059] 2. A total of four chip input indexers, 13, 23, 33, and 43, are used for each system.

[0060] 3. A total of four chip output indexers are used for each system: 14, 24, 34, and 44.

[0061] 4. Alignment System 18

[0062] 5. Check camera 26

[0063] The embodiments use one of the following:

[0064] 1. Controller / software to replace Figure 1 The four controllers / software shown are 15, 25, 35, and 45.

[0065] 2. A robotic loader 94 replaces eight chip indexers 13, 23, 33, 43, 14, 24, 34, and 44.

[0066] 3. A machine vision system 92 replaces an alignment system 18 and a camera system 26.

[0067] It has advantages in saving ground space for equipment:

[0068] In a normal photolithography facility, the reference... Figure 1 The four systems described will typically use the following ground spaces:

[0069] • Stepping tool 10: 1.5m x 1.5m

[0070] • Inspection tool 20: 1.5m x 1.5m

[0071] • Coating tool 30: 1.0m x 3.0m

[0072] • Developing tool 40: 1.0m x 3.0m

[0073] refer to Figure 1 The total area of ​​the four systems described (each requiring a small space between them) is approximately 15m². 2 .

[0074] refer to Figure 1 The described embodiment uses a photolithography apparatus, wherein the ground space is:

[0075] • Photolithography equipment: 1.3m x 2.3m = 3m 2

[0076] This is about 5 times smaller than the area of ​​a conventional system.

[0077] Compared to mercury lamps, LEDs offer additional advantages in terms of reduced cost and energy consumption. A mercury arc lamp combined with a reflector has an efficiency of approximately 2.5% in the 400nm to 450nm spectral range. In the example, the usable optical radiation is approximately 30W. The mercury lamp operates at (500 or 1000W).

[0078] In this embodiment, the LED source provides optical radiation up to 30W.

[0079] The lifespan of an LED largely depends on its usage. The LED should be turned off whenever exposures are not being performed. Typically, an exposure time of 3000-5000 hours can be expected.

[0080] The following is an example of how to calculate the total operating time of an LED module until it needs to be replaced:

[0081] Exposure time per exposure: 0.2 seconds

[0082] Number of times per chip: 20.

[0083] Chips processed per hour: 50.

[0084] Duty cycle: (0.5s*20*25) / 3600s=250 / 3600=0.069=7%.

[0085] Service life: 3000h / 7%~42000h.

[0086] If the duty cycle is smaller:

[0087] 40,000 / 24 days = 1,759 days = 4.7 years.

[0088] 4000 / 7% = 57000h = 2375 = 6.5 years.

[0089] If it is 5000 hours, then it is 71400h / 24=2976 days=8 years.

[0090] The cost of the LED module is €6,000, or approximately €1,000 per year.

[0091] A mercury lamp costing €600 needs to be replaced 6 times per year, which equals €3600 per year.

[0092] LEDs use only 0.5% of the power of mercury lamps, resulting in savings of approximately 42,000 watts per year.

[0093] Mercury lamps use 94% more power / exposure than LEDs. Mercury lamps also use 92% more watts / hour than LEDs. Besides the aforementioned cost and energy savings, another crucial aspect of using LEDs is the removal of mercury from the environment. Mercury is a hazardous material and requires proper handling. Removing this material helps make chip manufacturing facilities more environmentally friendly and healthier.

[0094] The advantages of LED lighting in terms of manufacturing process are:

[0095] LED illumination allows the exposure system to switch from standard GHI tools to i-line tools. i-line allows printing to a minimum of 0.6 μm, which is impossible with conventional tools (because GHI lines are limited to 1.0 μm in line width). Typically, wafer facilities would need to purchase a separate i-line-specific tool to perform these processes.

[0096] The following is a comparison of the operation of LEDs and mercury lamps.

[0097] mercury:

[0098] 1. The mercury lamp is always on.

[0099] 2. To align, the exposure shutter is closed and the green filter shutter is open (to align the wafer without exposing it).

[0100] 3. To prepare for exposure, the exposure shutter is opened and the energy dose time clock is activated (to measure intensity / time).

[0101] 4. When the required exposure energy is reached, the green shutter opens and the exposure shutter closes.

[0102] LED:

[0103] 1. The green LED turns on to align.

[0104] 2. For exposure, turn on the G / H / i line (or any combination thereof) (while turning off the green light).

[0105] In the latter case, the advantage is that there is no need to measure the dose time, because the LED only turns on when energy is needed.

[0106] It will be apparent to those skilled in the art that the innovative method of the present invention is implemented, at least in some embodiments, by a computer programmed with code to configure and directly control the system described above. Furthermore, the code required to program such a computer can, of course, be stored in and / or read from any computer-readable medium, such as a compressed optical disc (CD), a digital video optical disc (DVD), a flash memory storage device, a hard disk, random access memory (RAM), or read-only memory (ROM), and many other computer-readable media not specifically mentioned in this application.

[0107] As shown in the foregoing description of the present invention, various techniques can be used to implement the inventive concept without departing from its scope. Furthermore, although the invention has been described with specific reference to certain embodiments, those skilled in the art will understand that changes in form and detail can be made without departing from the spirit and scope of the invention. Therefore, the described embodiments are to be considered illustrative rather than restrictive in all respects. It should also be understood that the invention is not limited to the specific embodiments described herein, but is capable of many rearrangements, modifications, and substitutions without departing from its scope.

Claims

1. A photolithography apparatus, comprising: - Controller; - Exposure system; as well as -Chip loader system The controller is operable to configure and directly control the exposure system, the wafer loader system, and at least one of the following: - Inspection system; and - Resist treatment system.

2. The lithography apparatus of claim 1, further comprising the inspection system.

3. The photolithography apparatus as described in claim 1 or 2, further comprising the resist treatment system.

4. The photolithography apparatus as claimed in any of the preceding claims, wherein, The exposure system includes an LED illumination source that can be configured to emit G-line, H-line, and / or i-line radiation, and the controller is operable to configure and directly control the LED illumination source to select and emit G-line, H-line, or i-line radiation.

5. The photolithography apparatus as claimed in any of the preceding claims, wherein, The wafer loader system includes a pre-aligner and a carrier plate configured to receive wafers of multiple nominal diameters.

6. The lithography apparatus of any of the preceding claims further includes a machine vision system operable as a camera for the alignment system of the exposure system and as a camera for the inspection system.

7. The photolithography apparatus as claimed in any of the preceding claims, wherein, The resist treatment system includes a coating machine, an oven, and a developing machine, and the processor is operable to configure and directly control the coating machine, the oven, and the developing machine.

8. The photolithography apparatus as claimed in any of the preceding claims, wherein, The wafer loader system includes a wafer ID reader, and the processor is operable to configure and directly control the exposure system based on the readings from the wafer ID reader.

9. A computer program comprising computer-readable instructions that, when executed on a suitable computer device, cause the controller to configure and directly control at least one of the exposure system, the wafer loader system, the inspection system, and the resist treatment system according to any one of claims 1 to 8.

10. A computer program product comprising the computer program as described in claim 9.

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