Patent Description:
Inspecting wafers and photomasks (collectively, specimens) for defects and other characteristics is important for managing the semiconductor manufacturing process. Since the overall semiconductor manufacturing process involves hundreds of steps, it is critical to detect defects on the wafer or photomask early in the manufacturing process. To help detect defects that occur during the manufacturing process (as well as other specimen characteristics), manufacturers often employ automatic microscopic inspection systems.

Current microscopic inspection systems used by manufacturers are dedicated to either analyzing wafers for defects or analyzing photomasks for defects. Since wafers and photomasks have different dimensions and properties, separate microscopic inspection systems are used to accommodate these different dimensions and properties. For example, a stage included in an inspection system has a chuck attached to it that is specifically sized to hold either a wafer or photomask. Since a photomask is thicker than a wafer, existing chucks cannot be used for both photomasks and wafers. Unfortunately, buying and maintaining separate microscopic inspection systems can be very costly.

In a current wafer inspection system, in order to inspect both a wafer and a photomask using the same system, at the very least, a chuck that holds a specimen (e.g., a wafer or a photomask) to be examined would have to be changed each time a different type of specimen was placed on the chuck (e.g., switching from a wafer to a photomask or from a photomask to a wafer). Manually changing chucks between wafer and photomask inspections is disadvantageous, because additional adjustments (e.g., refocusing the objectives, reattaching vacuum connections, aligning automatic systems, and providing suitable safety features) are usually required when changing chucks. In particular, constantly switching between chucks can damage components of the inspection system (including the chuck itself), reduce the accuracy of specimen analyses, and introduce environmental contaminants into the inspection system. Also, changing out a chuck typically requires particularized knowledge, which operators of a microscopic inspection system may not have. Reducing the adjustments and calibrations that are necessary when switching between a wafer and photomask would reduce damage to the microscopic inspection system, minimize error, and allow for a repeatable, quality controlled microscopic inspection system.

Accordingly, it is desirable to provide a new mechanism for the combined inspection of wafers and photomasks.

<CIT> discloses a multi-use holder of a particle inspection device, wherein the multi-use holder is provided with a first mounting portion and a second mounting portion on which a wafer and a photomask are selectively mounted.

The present invention provides a chuck according to claim <NUM> and an automatic inspection system according to claim <NUM>.

A chuck according to the present invention comprises: a removable insert, wherein the removable insert is configured to support a wafer so that an examination surface of the wafer lies within a focal range when the chuck is in a first configuration, wherein the removable insert is inserted into the chuck in the first configuration; and a first structure forming a recess that has a depth sufficient to support a photomask so that an examination surface of the photomask lies within the focal range when the chuck is in a second configuration, wherein the removable insert is not inserted into the chuck in the second configuration. The chuck is adapted to be coupled to an inspection system, and the chuck includes a sensor adapted to cause electrical operations of the inspection system to be disabled when the removable insert is removed from the chuck.

An automatic inspection system according to the present invention comprises: an end effector that is coupled to a robotic system; a microscopic inspection station; a controller that controls one or more components of the automatic inspection system; and the chuck according to the present invention coupled to a stage. The automatic inspection system operates in a first operation mode when the chuck is in the first configuration, and the automatic inspection system operates in a second operation mode when the chuck is in the second configuration. The controller is configured to determine that the chuck is in the first configuration when an interlocking pin of the removable wafer insert has activated the sensor of the chuck.

In accordance with some embodiments of the disclosed subject matter, mechanisms (which can include systems, methods, devices, apparatuses, etc.) for automated microscopic inspection of wafers and photomasks are provided. Microscopic inspection (sometimes referred to as examination) refers to scanning, imaging, analyzing, measuring and any other suitable review of a specimen using a microscope.

In some embodiments, microscopic inspection can be used with a single or several wafer material types including opaque, transparent or semi-transparent. Further, in some embodiments, microscopic inspection can be configured to analyze one or all of substrate, epi, patterned and diced wafers, or individual devices (on the wafer).

Although the following description refers to <NUM> wafers and <NUM> photomasks, in some embodiments, the mechanisms described herein can be used to inspect any sized wafer and/or any sized photomask.

According to some embodiments of the disclosed subject matter, microscopic inspection can operate in two modes: a first mode for inspecting a wafer; and a second mode for inspecting a photomask. As described herein, in some embodiments, microscopic inspection can be configured to operate in a first mode for inspecting a wafer when a removable wafer insert is inserted into a chuck and to operate in a second mode for inspecting a photomask when the removable wafer insert is removed from the chuck.

<FIG> (front perspective view) and 1B (side view) illustrate an example inspection system <NUM> according to some embodiments of the disclosed subject matter. At a high level, the basic components of inspection system <NUM>, according to some embodiments, include an automated microscopic examination station <NUM>, a pre-aligner <NUM>, a robotic wafer handling system <NUM>, a load port apparatus <NUM>, and electronics comprising hardware, software, and/or firmware.

In some embodiments, many of the components of inspection system <NUM>, as shown in <FIG> and <FIG>, can be enclosed within a cabinet housing made from aluminum, steel, plastic, glass, and/or any other suitable material for providing a micro clean environment within the cabinet housing. The cabinet housing can include one or more access doors that provide access to the internal components of inspection system <NUM>. Further, in some embodiments, an air filtration system <NUM> for providing a micro clean environment within the cabinet can be placed, for example at the top of the cabinet housing. The cabinet housing can include one or more storage regions, located for example at the bottom of the cabinet housing, for housing a robotic wafer handling system and/or a vacuum source. The cabinet housing can also include one or more platforms for mounting the various components of inspection system <NUM>. In some embodiments, inspection system <NUM> can also be partially or completely open. In some embodiments, a variety of cabinet housing configurations can be used in accordance with some embodiments of the disclosed subject matter.

As shown in <FIG> and <FIG>, inspection system <NUM> includes an automated microscopic examination station <NUM>. In some embodiments, automated microscopic examination station <NUM> comprises oculars, such as an ocular and/or a camera, a light source, an illuminator, one or more objective lenses, a stage <NUM> and a chuck <NUM> coupled to the stage <NUM>.

Automated microscopic examination station <NUM> can use any suitable type of microscope. For example, in some embodiments, the microscope can be an optical microscope, an electron microscope, a scanning probe microscope or any other suitable microscope. More particularly, automated microscopic examination station <NUM> can be implemented using the nSpec® optical microscope available from Nanotronics Imaging, Inc. of Cuyahoga Falls, OH. Microscopic examination station <NUM> can be configured to inspect a specimen (e.g., a wafer or a photomask) and automatically report on selected characteristics of the specimen.

According to some embodiments, automated microscopic examination station <NUM> can include, one or more objectives. The objectives can have different magnification powers and/or be configured to operate with brightfield/darkfield microscopy, atomic force microscopy (AFM), differential interference contrast (DIC) microscopy, and/or any other suitable form of microscopy. The objective and/or microscopy technique used to inspect a specimen can be controlled by software, hardware, and/or firmware in some embodiments. In some embodiments, any suitable settings and/or adjustments to the components of automated microscopic examination station <NUM> can be controlled by software, hardware and/or firmware.

In some embodiments, an XY translation stage can be used for stage <NUM>. The XY translation stage can be driven by stepper, servo, linear motor, and/or any other suitable mechanism.

In some embodiments, as shown in <FIG>, stage <NUM> and chuck <NUM> of automated microscopic examination station <NUM> can be mounted to isolation platform <NUM> located above a base platform <NUM> of the cabinet housing. For example, isolation platform <NUM> can be secured to the bottom frame of the cabinet housing. More particularly, in some embodiments, isolation platform <NUM>, can be bolted into air pads <NUM>, or any other suitable isolation mechanisms for fastening isolation platform <NUM> to the bottom frame of the cabinet housing. Air pads <NUM> can help reduce vibration (e.g., from fans of other components in inspection system <NUM>) to a specimen on chuck <NUM> during examination.

In some embodiments, an extended arm <NUM> can be mounted to isolation platform <NUM>. A motorized Z-column <NUM> coupled to the optics portion of the microscopic examination station <NUM> can be mounted to extended arm <NUM>. In some embodiments, the optics portion can be configured to move up and down on motorized Z-column <NUM>. Mounting the entire microscopic examination station <NUM> to isolation platform above the base platform of the cabinet housing can help to distribute the weight of the microscopic examination station <NUM> evenly and minimize vibration to the microscopic examination station <NUM> during examination.

Pre-aligner <NUM> can be a stand-alone unit or integrated into the robot wafer handling system. In some embodiments, as shown in <FIG>, pre-aligner <NUM> is a stand-alone unit that is mounted with bolts or other suitable fasteners to a base platform of the cabinet. Pre-aligner <NUM> can be used for orienting and/or centering a wafer or other suitable specimen so that the specimen is properly oriented and centered when it is placed on chuck <NUM> for examination. In some embodiments, pre-aligner <NUM> can use an indicator, for example a notch (e.g., on wafers <NUM> or greater) or a flat (e.g., on wafers less than <NUM>) to orient the wafer so that the wafer is placed on the stage with a specific orientation. Pre-aligner <NUM> can rotate the wafer up to <NUM> degrees to find the indicator. In some embodiments, pre-aligner <NUM> can measure center location and orientation of a wafer in a single rotation.

According to some embodiments, when a specimen is received by pre-aligner <NUM>, pre-aligner <NUM> can be configured to turn on a vacuum to hold the specimen in place during the centering and/or aligning process. The pre-aligner can also be configured to start the alignment and/or centering process only after the vacuum is turned on. When the pre-aligner has completed handling the wafer, the pre-aligner vacuum can be configured to shut off.

Note that, in some embodiments, any suitable pre-aligner can be used with inspection system <NUM>.

Pre-aligner <NUM> can be configured to support wafers of any suitable size (e.g., <NUM> to <NUM>, and/or any other suitable size). In some embodiments, pre-aligner <NUM> can also be configured to communicate with the other components of inspection system <NUM>. In some embodiments, communications and operations of pre-aligner <NUM> can be controlled by software, hardware and/or firmware.

In some embodiments, a robotic wafer handling system for transferring a wafer or other suitable specimen within inspection system <NUM> can include a base housing, a motor (not shown), a multi-axis extendable arm <NUM>, and an end effector <NUM>. As shown in <FIG>, the base of the robotic wafer handling system can be stored in a region <NUM> below a base platform <NUM> of the cabinet housing. Multi-axis extendable arm <NUM> can extend above base platform <NUM> and can have two ends. One end can be coupled to the base of the robotic wafer handling system and the other end can be coupled to end effector <NUM>. In some embodiments, end effector <NUM>, as shown in <FIG>, can be in the shape of a multi-fingered hand. Different types of end effectors can be used with the robotic wafer handling system in some embodiments. For example, in some embodiments, a vacuum end effector can be used that applies vacuum pressure to hold a specimen in place on the end effector. As another example, in some embodiments, an edge grip end-effector can be used that that uses any suitable gripping mechanism to hold the specimen in place on the end effector.

Note that, in some embodiments, multiple end effectors or a dual end effector can be used with inspection system <NUM> to handle two or more specimens at different locations within inspection system <NUM>.

Note that, in some embodiments, any suitable robotic wafer handling system(s) that includes any suitable multi-axis extendable arm and/or end effector can be used with inspection system <NUM>. In some embodiments, end effector <NUM> of the robotic wafer handling system can be configured to support any suitable size wafers, such as, for example, <NUM> to <NUM> size wafers. In some embodiments, end effector <NUM> can be configured to support a photomask. In some embodiments, all settings, communications, and operations of the robotic wafer handling system can be controlled by software, hardware and/or firmware.

In some embodiments, a motor housed in the base of the robotic wafer handling system can control the movement of multi-axis extendable arm <NUM> and end effector <NUM>. For example, the motor can drive and control multi-axis extendable arm <NUM> and end effector <NUM> to select a wafer from a cassette storage and move the wafer to different locations within inspection system <NUM>. In some embodiments, end effector <NUM> can transfer the wafer from the cassette storage to pre-aligner <NUM> for alignment, from pre-aligner <NUM> to chuck <NUM> for examination, and from chuck <NUM> back to the cassette storage when examination of the wafer is complete.

In some embodiments, inspection system <NUM> can include a load port apparatus <NUM> (as shown in <FIG> and <FIG>) for transferring wafers and/or other suitable specimens between a storage container and inspection system <NUM>. In some embodiments, load port apparatus <NUM> can be mounted to the outside of the cabinet housing of inspection system <NUM>. Load port apparatus <NUM> can include a door <NUM> that provides access to the inside of inspection system <NUM>. In some embodiments, the door can be configured to slide up and down to provide access to the inside of inspection system <NUM>. Load port apparatus <NUM> also includes a platform <NUM> for holding a wafer carrier or other suitable specimen carrier.

In some embodiments, a front opening unified pod (FOUP) <NUM> can be placed on platform <NUM> of load port apparatus <NUM>. FOUP <NUM> can include various coupling plates, pins and holes for securing the FOUP to the load port platform. In some embodiments, FOUP <NUM> can be a plastic enclosure designed to cleanly and securely hold wafers and to allow wafers to be transferred from FOUP <NUM> to microscopic inspection system <NUM> for processing. FOUP <NUM> can include a side door that can be opened to provide access to wafers inside. In some embodiments, for example, FOUP <NUM> can hold <NUM> wafers. In some embodiments, a side door of FOUP <NUM> can be aligned with load port door <NUM> to create a seal. Load port apparatus <NUM> can be configured to draw the mated doors of load port apparatus <NUM> and FOUP <NUM> down and up. In one position (e.g., the down position), the wafers in FOUP <NUM> can be exposed to the inside of the inspection system <NUM> and provide access to end effector <NUM> to select a wafer. In a second position (e.g., the up position), both FOUP <NUM> and inspection system <NUM> are sealed off from each other, restricting access between them. FOUP <NUM> can include sensors to detect and communicate with inspection system <NUM> when wafers are present in FOUP <NUM>.

In some embodiments, end effector <NUM> can include one or more sensors for mapping the inside of FOUP <NUM> to detect each location in FOUP <NUM> that stores a wafer.

<FIG>, shows a side view of inspection system <NUM> and some of its components, according to some embodiments of the disclosed subject matter. In particular, <FIG> shows an emergency power off (EPO) switch <NUM> coupled to the outside of inspection system <NUM> that allows an operator to electrically shut down all robotic operations of the robotic wafer handling system, as well as any other electrical operation of inspection system <NUM>, when the switch is activated. In some embodiments, the vacuum remains on to prevent damage to the specimen.

The cabinet housing of inspection system <NUM>, can also include an access door <NUM> that provides access to components within the inspection system. Access door <NUM> is coupled to an interlock hinge <NUM>, or any other suitable switch, that is designed to disable any moving component within inspection system <NUM> when access door <NUM> is open. In some embodiments, any access door to the inspection system <NUM> can include a switching mechanism that is designed to disable any moving component within inspection system <NUM> when the door is opened.

In some embodiments, the electronics controlling inspection system <NUM> can be located in a separate compartment of the cabinet housing, for example, below automated microscopic examination station <NUM>. In some such embodiments, electronics controlling inspection system <NUM> can be accessed using access door <NUM>. In some embodiments, the electronics can include any suitable hardware, software, and/or firmware for controlling the operation, communication, and settings of the components of the inspection system <NUM>, as described herein. In some embodiments, inspection system <NUM> includes software and/or hardware to provide motion control, specimen handling, safety interlocks, and analysis of wafers and photomasks. Hardware can include, for example, computers, microprocessors, microcontrollers one or more EPROMS, EEPROMs, application specific integrated circuits (ASICs) in addition to other hardware elements. In some embodiments, individual components within inspection system <NUM> can include their own software, firmware, and/or hardware to control the individual components and communicate with other components in inspection system <NUM>.

Inspection system <NUM> can also include one or more display monitors <NUM> coupled to the outside of inspection system <NUM>. Display monitors <NUM> can display images captured by microscopic examination station <NUM>. An adjustable swingarm <NUM> for placing input devices (e.g., a keyboard, mouse or joystick) for controlling the electronics can also be coupled to inspection system <NUM>, and located, for example, below display monitors <NUM>.

<FIG> (top view) and <FIG> (bottom view), show the general configuration of an embodiment of a chuck <NUM> and a removable wafer insert <NUM> in accordance with some embodiments of the disclosed subject matter. Chuck <NUM> can be formed from aluminum, steel and/or any other suitable material(s). Chuck <NUM> is designed to support both a photomask and a wafer at different times. In some embodiments, chuck <NUM> is C-shaped with a relief area <NUM> (as shown in <FIG>) designed to allow access to a two-fingered end effector <NUM> for placing or removing a specimen on to or off of the chuck. Chuck <NUM> can be mounted to the top surface of stage <NUM> of microscopic examination station <NUM>, using standard fasteners like spring screws or leveling screws.

In some embodiments, chuck <NUM> can include a removeable wafer insert <NUM> designed to support a wafer and to allow the insert to be removed from the base of chuck <NUM>. In some embodiments, chuck <NUM> can be in a first configuration when removable wafer insert <NUM> is inserted in chuck <NUM>, and, in the first configuration, chuck <NUM> can be used to support a wafer for inspection by inspection system <NUM>. In some embodiments, chuck <NUM> can be in a second configuration when removable wafer insert <NUM> is not inserted in chuck <NUM>, and, in the second configuration, chuck <NUM> can be used to support a photomask for inspection by inspection system <NUM>.

Removable wafer insert <NUM> can include locating pins <NUM> (as shown in <FIG>) that engage holes <NUM> (as shown in <FIG>) that align removable wafer insert <NUM> to a corresponding mate <NUM> located within a recess of chuck <NUM>. In some embodiments, corresponding mate <NUM> can include one or more vacuum cups <NUM>. Vacuum cups <NUM> can be connected to a vacuum source (not shown) and designed to provide a vacuum interface to secure removable wafer insert <NUM> to chuck <NUM> when inspection system <NUM> is used to inspect a wafer, and/or to secure a photomask (e.g., photomask <NUM>, as shown in and described below in connection with <FIG>) to chuck <NUM> when inspection system <NUM> is used to inspect photomask. In some embodiments, the vacuum source will not turn on until all the access doors to the cabinet of inspection system <NUM> are closed. Note that, in some embodiments, any other suitable fastening mechanism(s) can be used to secure removable wafer insert <NUM> to chuck <NUM>.

Removable wafer insert <NUM> can also include an interlocking safety mechanism like an interlocking pin <NUM> (as shown in <FIG>). Interlocking pin <NUM> can activate a sensor <NUM>, located on chuck <NUM>, for sensing when removable wafer insert <NUM> is inserted into or removed from chuck <NUM>. Sensor <NUM> can be any suitable sensor for detecting the presence of pin <NUM>, such as an optical sensor or an electro-mechanical switch. The output of sensor <NUM> can be connected to the electronics of inspection system <NUM> via interlock sensor connector <NUM> (as shown in <FIG>) and can be configured to enable certain electrical operations (e.g., the electrical operations of the robotic wafer handling system) when removable wafer insert <NUM> is inserted into chuck <NUM> and to disable certain electrical operations (e.g., the electrical operations of the robotic wafer handling system) when removable wafer insert <NUM> is removed from chuck <NUM>.

The thickness of removable wafer insert <NUM>, in some embodiments, can be thick enough to cause the top surface of insert <NUM> to be at the same level and flat with respect to outer wafer support surface <NUM>. <FIG> shows a simple cross-sectional illustration of a chuck <NUM>, a removable insert <NUM>, and a wafer <NUM>. As illustrated, the top of insert <NUM> can be flat and level with outer wafer support surface <NUM> so that a wafer <NUM> can lie flat across insert <NUM> and surface <NUM>.

<FIG> shows a simple cross-sectional illustration of a chuck <NUM> and a photomask <NUM>. As illustrated, the top of photomask <NUM> can be at the same level and flat with respect to outer wafer support surface <NUM> in some embodiments. Thus, in such embodiments, the height (h<NUM>) at the top of the photomask with respect to the bottom of the chuck can be different than the height (h<NUM>) at the top of a wafer when sitting on surface <NUM> and insert <NUM> (as shown in <FIG>) by an amount equal to the thickness of a wafer. For example, in some embodiments, h<NUM> and h<NUM> can be different but both be within a focal range (which can be any suitable thickness, such as <NUM> thick, in some embodiments) of automated microscopic examination station <NUM> (<FIG>).

In some embodiments, rather than being at the same level and flat with respect to outer wafer support surface <NUM>, the top of photomask <NUM> can be slightly higher than outer wafer support surface <NUM> (e.g., by an amount around or equal to the thickness of a wafer) so that the height (h<NUM>) at the top of the photomask with respect to the bottom of the chuck is substantially the same as the height (h<NUM>) at the top of a wafer when sitting on surface <NUM> and insert <NUM> (as shown in <FIG>).

In some embodiments, removable wafer insert <NUM> and chuck <NUM> can include multiple vacuum channels (e.g., vacuum ring <NUM> and outer vacuum channel <NUM> as shown in <FIG>) for providing vacuum pressure at various locations on chuck <NUM> to hold a specimen firmly in place during examination. The vacuum configuration for chuck <NUM> can provide any suitable vacuum pressure for the type of specimen being examined.

As shown in <FIG>, in some embodiments, vacuum ring <NUM> can be located on removable wafer insert <NUM> and outer vacuum channel <NUM> can be located in outer wafer support surface <NUM>. The vacuum can be supplied via vacuum valves <NUM> and <NUM>, which, in some embodiments, can be located along the outer edge of chuck <NUM> so as not to interfere with the vacuum supply when removable wafer insert <NUM> is removed from chuck <NUM>. Vacuum valves <NUM> and <NUM> can be coupled (e.g., via a hose) with a vacuum source, which can be located in some embodiments within inspection system <NUM>. In some embodiments, both vacuum valves <NUM> and <NUM> can be open when a wafer is placed on chuck <NUM> and provide vacuum flow to both vacuum ring <NUM> and outer vacuum channel <NUM>. In some embodiments, when a photomask, which can have a smaller surface area than a wafer, is placed on chuck <NUM>, then only vacuum valve <NUM> can be opened to provide sufficient vacuum support to vacuum cups <NUM> for providing vacuum support to a photomask. For example, when photomask <NUM> (as shown in <FIG>) is placed on chuck <NUM>, the vacuum supply to outer vacuum channel <NUM> can remain turned off, because photomask <NUM> does not extend to vacuum channel <NUM>. In some embodiments, any suitable vacuum configurations can be used with chuck <NUM>. In some embodiments, the source vacuum can be regulated to 60KPa, which can be applied for both wafers and photomasks.

<FIG> shows an illustration of an example of vacuum channels <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> for connecting valves <NUM> and <NUM> (<FIG>) to vacuum ring <NUM>, vacuum channel <NUM> and vacuum cups <NUM>.

Chuck <NUM> can also include any suitable number of leveling screws 320A and 320B (e.g., <NUM> point leveling screws, and/or any other suitable number and/or type of leveling screws) to enable an operator to ensure that outer wafer support surface <NUM> of the chuck is level and flat. More particularly, one set of leveling screws 320A can be used to level outer wafer support surface <NUM> with respect to the focal range (which can be any suitable thickness, such as <NUM> thick, in some embodiments) of automated microscopic examination station <NUM> (<FIG>) by repositioning the chuck with respect to a lower structure to which it is attached. Another set of leveling screws 320B can be used to level and adjust the height of removable wafer insert <NUM> when it is inserted into chuck <NUM> by repositioning corresponding mate <NUM> with respect to the remainder of the chuck.

In some embodiments, chuck <NUM> can be designed to support wafers of different sizes and thicknesses by using wafer inserts of different thicknesses. For example, a first removable wafer insert <NUM> can have a first thickness (e.g., <NUM> when used with a chuck having a recess that is <NUM> deep with respect to a point within the focal range of automated microscopic examination station <NUM>) for a first wafer thickness (e.g., <NUM>) and a second removable wafer insert <NUM> can have a second thickness (e.g., <NUM> when used with the chuck having a recess that is <NUM> deep with respect to the point within the focal range of automated microscopic examination station <NUM>) for a second wafer thickness (e.g., <NUM>) so that the combined thickness (e.g., <NUM>) of the insert and the wafer put the examination surface of the wafer within the focal range of automated microscopic examination station <NUM> (<FIG>).

Other features, like the configuration of vacuum channels and the placement of leveling screws, can be suitably designed based on the size of the wafers.

<FIG> (a top perspective view of example chuck <NUM> when photomask <NUM> is on the chuck) and <FIG> (a top perspective view of example chuck <NUM> before photomask <NUM> is placed on the chuck) show an illustration of chuck <NUM> in which removable wafer insert <NUM> is removed to allow for photomask <NUM> to be placed on chuck <NUM>. As shown, chuck <NUM> can include four corner shelves <NUM> that create a recess in the chuck (which can be at least as thick as the thickness of photomask <NUM> in some embodiments) for placing the surface of photomask <NUM> within the same microscopic inspection focal range (which can be any suitable thickness, such as <NUM>, in some embodiments) as a wafer when the photomask is positioned on the chuck, as described above in connection with <FIG>. Chuck <NUM> can also include first and second relief areas <NUM> for placing or removing photomask <NUM> on to or off of chuck <NUM>. In some embodiments, keeping the surface of a wafer and the surface of a photomask in the same focal range (which can be any suitable thickness, such as <NUM>, in some embodiments) eliminates the need to change the focus of the microscopic examination station <NUM> when switching between inspecting a wafer and inspecting a photomask.

As shown in <FIG>, in some embodiments, vacuum cup <NUM> (as described above in connection with <FIG>) can provide a vacuum interface for photomask <NUM> to hold the photomask firmly in place during inspection. <FIG> also shows corner shelves <NUM>, which are also designed to provide support to photomask <NUM>.

<FIG>, with further reference to <FIG>, shows at a high level, a wafer loading operation <NUM> of inspection system <NUM>, in accordance with some embodiments of the disclosed subject matter. The wafer loading process <NUM> can use inspection system <NUM>.

At <NUM>, FOUP <NUM> can be placed on load port apparatus <NUM>, so that the door of FOUP <NUM> and load port door <NUM> fasten together in a sealable manner. FOUP <NUM> and load port door <NUM> can be lowered together, exposing the wafers in FOUP <NUM> to the inside of inspection system <NUM> and providing access to end effector <NUM> to select a wafer.

At <NUM>, robotic end effector <NUM> can map the FOUP to determine how many wafers are in the FOUP and where they are located. In some embodiments, robotic end effector <NUM> can map the FOUP using any suitable sensors associated with robotic end effector <NUM>. End effector <NUM> can then pick up a wafer from FOUP <NUM>, and transfer the wafer to pre-aligner <NUM>. In some embodiments, a vacuum can be turned on when or after a wafer is picked up for keeping the wafer on end effector <NUM> and the vacuum can be turned off after the wafer is transferred to pre-aligner <NUM>.

At <NUM>, pre-aligner <NUM> can center and/or orient a wafer (e.g., by using a notch or a flat). In some embodiment, pre-aligner <NUM> can turn on a vacuum when or after it receives the wafer before it starts any wafer centering and/or aligning procedure, and turn off the vacuum when or after the wafer centering and/or aligning procedure is completed.

At <NUM>, end-effector <NUM> can pick up a wafer from pre-aligner <NUM> and place the wafer on chuck <NUM> for inspection by automated microscopic examination station <NUM>. Vacuum pressure for chuck <NUM> can be turned on when or after the wafer is placed on chuck <NUM>.

At <NUM>, process <NUM> can perform microscopic inspection on the wafer using any suitable technique or combination of techniques. For example, as described above in connection with <FIG> and <FIG>, process <NUM> can use an automated microscopic examining station that includes any suitable type of microscope (e.g., an optical microscope, an electron scanning microscope, a scanning probe microscope, and/or any other suitable type of microscope) to obtain any suitable information during inspection of the wafer.

At <NUM>, when or after inspection of the wafer is completed, vacuum pressure can be turned off and end effector <NUM> can retrieve the wafer from chuck <NUM> and return the wafer to FOUP <NUM>.

In some embodiments, once all the wafers are inspected, load port door <NUM> and FOUP <NUM> can be raised together, sealing off the access between FOUP <NUM> and inspection system <NUM>. In some embodiments, vacuum pressure can be applied when a wafer is present on end effector <NUM>, and the vacuum for the end effector can be turned off when the wafer is transferred to another component of inspection system <NUM>.

Note that, in some embodiments, wafers can be manually loaded into inspection system <NUM> and placed directly on chuck <NUM> without using FOUP <NUM>.

Additionally, note that, in some embodiments, process <NUM> can be performed in response to determining that removable wafer insert <NUM> (as shown in and described above in connection with <FIG> and <FIG>) has been inserted in chuck <NUM>. For example, in some embodiments, process <NUM> can be performed in response to determining that interlocking pin <NUM> of removable wafer insert <NUM> has activated sensor <NUM> of chuck <NUM>, as described above in connection with <FIG> and <FIG>.

<FIG>, with further reference to <FIG>, shows at a high level, a photomask loading operation <NUM> of inspection system <NUM>, in accordance with some embodiments of the disclosed subject matter. Photomask loading process <NUM> can use inspection system <NUM>.

At <NUM>, access door <NUM> can be opened (as shown in <FIG>). This door can be opened in any suitable manner in some embodiments. For example, this door can be opened manually by an operator or automatically by an actuator in some embodiments.

At <NUM>, in some embodiments, interlock hinge <NUM> can be activated in response to detecting that access door <NUM> has been opened. In some such embodiments, process <NUM> can disable any moving component within inspection system <NUM>, including disabling end effector <NUM>.

At <NUM>, removable wafer insert <NUM> (as shown in <FIG>) can be removed and a photomask can be recessed into chuck <NUM>. Insert <NUM> can be removed in any suitable manner, such as manually by an operator or using an automated mechanism. Photomask can be recessed into chuck <NUM> in any suitable manner, such as manually by an operator or using an automated mechanism.

At <NUM>, microscopic examination station <NUM> can inspect the photomask. In some embodiments, microscopic examination station <NUM> can use any suitable parameters and techniques for inspecting the photomask. For example, in some embodiments, microscopic examination station <NUM> can use the same or a different focus and objective as was used to inspect a wafer, as described above in connection with <FIG>. As another example, in some embodiments, microscopic examination station <NUM> can use a different microscopic technique (e.g., using AFM microscopy) than a technique used to inspect a wafer.

At <NUM>, after inspection of the photomask, the photomask can be removed from chuck <NUM> and removable wafer insert <NUM> can be inserted into chuck <NUM>. Photomask can be removed from chuck <NUM> in any suitable manner, such as manually by an operator or using an automated mechanism. Insert <NUM> can be inserted in any suitable manner, such as manually by an operator or using an automated mechanism.

At <NUM>, access door <NUM> can be closed when or after removable wafer insert <NUM> is inserted into chuck <NUM>. Access door <NUM> can be closed in any suitable manner, such as manually by an operator or using an automated mechanism.

At <NUM>, the robotic wafer handling system of inspection system <NUM> can be enabled, as described above in connection with <FIG>.

Note that, in some embodiments, process <NUM> can be performed in response to determining that removable wafer insert <NUM> (as shown in and described above in connection with <FIG> and <FIG>) is not inserted in chuck <NUM>. For example, in some embodiments, process <NUM> can be performed in response to determining that interlocking pin <NUM> of removable wafer insert <NUM> has not activated sensor <NUM>, as described above in connection with <FIG> and <FIG>.

Additionally, note that, in some embodiments a photomask can also be automatically loaded into inspection system <NUM>, similar to the techniques used for automatically loading wafers into the inspection system. For example, in some embodiments, a specially designed photomask storage container can be loaded onto load port apparatus <NUM>. The front cover of the photomask storage container and load port door <NUM> can be lowered, exposing the photomasks inside the photomask storage container to the inside of inspection system <NUM>. The photomask storage container and/or end effector <NUM> can be designed to sense the presence of a photomask and communicate with the control system of inspection system <NUM> to perform operations appropriate for photomask inspection. The photomask storage container can be designed to include a designated area for storing removable wafer insert <NUM>. Before any photomask is loaded into inspection system <NUM>, end effector <NUM> can be configured to remove removable wafer insert <NUM> from chuck <NUM> and place it in a designated area in the photomask storage container. Once removable wafer insert <NUM> has been removed, end effector <NUM> can select a photomask from the photomask storage container and transfer it to chuck <NUM> for inspection and/or imaging by microscopic examination station <NUM>. After inspection of the photomask, end effector <NUM> can pick up the photomask from chuck <NUM> and return the photomask to the photomask storage container. Once all the photomasks are inspected, end effector <NUM> can select removable wafer insert <NUM> and place it back on chuck <NUM>.

<FIG>, with further reference to <FIG>, shows at a high level an example of logic rules <NUM> for interlocking safety features of an inspection system, such as inspection system <NUM>, in accordance with some embodiments of the disclosed subject matter.

As shown in <FIG>, according to some embodiments, an inspection system can include three interlocking mechanisms for determining whether a robotic wafer handling system, such as the one shown in and described above in connection with <FIG>, is to be deactivated or activated.

In some embodiments, the robotic wafer handling system can be disabled at <NUM> in response to determining that an emergency power off (EPO) button has been activated (at <NUM>), that an access door to the enclosed inspection system <NUM> is not closed (at <NUM>), or that a wafer insert is not present in chuck <NUM> (at <NUM>). Note that, in some embodiments, any one of an activated EPO button, not closed access door, and/or lack of removable wafer insert in chuck <NUM> can disable all robotic operations at <NUM> by the robotic wafer handling system and/or moveable components within inspection system <NUM>.

Conversely, in some embodiments, the robotic operations of the robotic wafer handling system can be enabled at <NUM> in response to determining that the following conditions have been met: the EPO button is not enabled (<NUM>), access door <NUM> to inspection system <NUM> is closed (<NUM>), and removable wafer insert <NUM> is inserted into chuck <NUM> (<NUM>).

The division of when the particular portions of processes <NUM>, <NUM>, and/or <NUM> are performed can vary, and no division or a different division is within the scope of the subject matter disclosed herein. Note that, in some embodiments, blocks of processes <NUM>, <NUM>, and/or <NUM> can be performed at any suitable times. It should be understood that at least some of the portions of processes <NUM>, <NUM>, and/or <NUM> described herein can be performed in any order or sequence not limited to the order and sequence shown in and described in the <FIG>, <FIG>, and <FIG> in some embodiments. Also, some of the portions of processes <NUM>, <NUM>, and/or <NUM> described herein can be or performed substantially simultaneously where appropriate or in parallel in some embodiments. Additionally or alternatively, some portions of processes <NUM>, <NUM>, and/or <NUM> can be omitted in some embodiments.

Claim 1:
A chuck (<NUM>) for an automatic inspection system (<NUM>), comprising:
a removable insert (<NUM>), wherein the removable insert (<NUM>) is configured to support a wafer so that an examination surface of the wafer lies within a focal range when the chuck (<NUM>) is in a first configuration, wherein the removable insert (<NUM>) is inserted into the chuck (<NUM>) in the first configuration; and
a first structure forming a recess that has a depth sufficient to support a photomask so that an examination surface of the photomask (<NUM>) lies within the focal range when the chuck (<NUM>) is in a second configuration, wherein the removable insert (<NUM>) is not inserted into the chuck (<NUM>) in the second configuration,
wherein the chuck (<NUM>) is adapted to be coupled to the inspection system (<NUM>), and wherein the chuck (<NUM>) includes a sensor (<NUM>) adapted to cause electrical operations of the inspection system (<NUM>) to be disabled when the removable insert (<NUM>) is removed from the chuck (<NUM>).