Patent Description:
Substrates, such as semiconductor substrates, are routinely inspected during processing at independent inspection stations to ensure compliance with predetermined quality control standards. Different inspection techniques provide comprehensive data regarding products and processes. However, comprehensive inspections can be time consuming, thus reducing throughput, due to the number of inspection stations required and the resulting transfer time of moving substrates therebetween. Thus, device manufacturers are often faced with the decision of choosing between thorough inspection stations with burdensome inspection/transfer times, or foregoing certain inspection processes. An example of a substrate rotary loader shows <CIT> which relates to a loading and unloading device of solar cell wafers. A wafer transfer unit with loader, a crack detection sensor, two indices and transfer conveyors are described. An index has a cross structure with a body portion and four arms each provided with a gripper for holding a wafer by vacuum. Each index has a body portion which may be rotated by a motor. Two rows of feed conveyors are provided. <CIT>, <CIT>, <CIT>, <CIT>, and <CIT> relate to transport equipment for substrates as well.

However, as inspection processes have continued to decrease the amount of time required to complete required inspection steps, loading apparatuses also need to be improved to be able to keep up with the increased throughput.

Thus, there is a need for an improved substrate loading apparatus for use with inspection systems.

In one embodiment, a loading module for a substrate inspection system or substrate inspection station is disclosed herein. The loading module includes: a first arm including a first end, a second end opposite the first end, a first substrate gripper disposed on the first end of the first arm, and a second substrate gripper disposed on the second end of the first arm, and a second arm including a first end, a second end opposite the first end, a first substrate gripper disposed on the first end of the second arm, and a second substrate gripper disposed on the second end of the second arm; a first rotatable support member coupled to the first arm, and a second rotatable support member coupled to the second arm; a conveyer system including a conveyor belt disposed between the first and second rotatable support members; and at least one actuator coupled to the first and second rotatable support members. The at least one actuator is configured to rotate the first arm about the first rotatable support member and the second arm about the second rotatable support member to selectively position the first and second substrate grippers of the first and second arms over the conveyor system in a same substrate release location, wherein the substrate release location is a location that allows a substrate held by any one of the the first and second substrate grippers of the first and second arms to be released onto the conveyor belt of the conveyor system.

According to an example, a loading module for a substrate inspection system is disclosed herein. The loading module includes: two arms; a plurality of grippers, two rotatable support members; a conveyer; and at least one actuator. Each arm has a first end and a second end, wherein the second end is opposite the first end. Each substrate gripper is disposed at a respective end of each arm. Each rotatable support member is coupled to a respective one of the arms. The conveyor is disposed between the rotatable support members. The at least one actuator is configured to rotate the arms about the rotatable support members to selectively position the grippers over the conveyor in a location that allows a substrate held by the gripper to be released onto the conveyor. This embodiment may also be combined with embodiments according to the dependent claims.

In another example, a loading module for a substrate inspection system is disclosed herein. The loading module includes a conveyor, two cassette holders disposed on opposite sides of the conveyor, two arms, two rotatable support members, and two actuators. Each arm includes a first end, a second end opposite the first end, a first gripper disposed on the first end of the first arm, and a second gripper disposed on the second end of the second arm. Each rotatable support member is coupled to one of the arms. Each actuator is coupled to a respective rotatable support member. The actuators are configured to rotate the arms about the rotatable support members such that the arms rotate in an indexing fashion between positions that allow the grippers to transfer substrates between the cassette holders and the conveyor.

In another embodiment, a method for loading substrates is disclosed herein. The method includes rotating a first arm a predetermined amount in a first direction to pick up a first substrate with a gripper disposed at a first end of the first arm, rotating the first arm a predetermined amount in the first direction and rotating a second arm a predetermined amount in a second direction to pick up a second substrate with a gripper disposed at a first end of the second arm, wherein the second direction is opposite the first direction, rotating the second arm a predetermined amount in the second direction and rotating the first arm a predetermined amount in the first direction such that the gripper disposed at the first end of the first arm is positioned in a substrate release position over a conveyor belt of a conveyor system (<NUM>) and releases the first substrate onto the conveyor belt, rotating the first arm a predetermined amount in the first direction and rotating the second arm a predetermined amount the second direction such that the gripper disposed at the first end of the second arm is positioned in the substrate release position over the conveyor belt of the conveyor system (<NUM>) and releases the second substrate onto the conveyor belt, and continuing to rotate the first arm in the first direction and the second arm in the second direction in a stepping fashion to alternately pick up and load other substrates.

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention, which is defined by the appended claims, may admit to other equally effective embodiments.

For clarity, identical reference numerals have been used, where applicable, to designate identical elements that are common between figures. Additionally, elements of one embodiment may be advantageously adapted for utilization in other embodiments described herein.

<FIG> illustrates a top plan view of a substrate inspection system <NUM>, according to one embodiment. The inspection system <NUM> includes a loading module <NUM>, a modular unit <NUM>, and a sorting unit <NUM>. In one embodiment, the modular unit <NUM> may include one or more metrology stations. The metrology stations may include, by way of example only, any of the following: a micro-crack inspection unit, a thickness measuring unit, a resistivity measuring unit, a photoluminescence unit, a geometry inspection unit, a saw mark detection unit, a stain detection unit, a chip detection unit, and/or a crystal fraction detection unit. The micro-crack inspection unit may be, by way of example only, configured to inspect substrates for cracks, as well as to optionally determine crystal fraction of a substrate. The geometry inspection unit may be configured, by way of example only, to analyze surface properties of a substrate. The saw mark detection unit may be configured, by way of example only, to identify saw marks including groove, step, and double step marks on a substrate. The metrology stations may also include other examples beyond those listed.

The loading module <NUM>, the modular unit <NUM>, and the sorting unit <NUM> are connected in a linear arrangement such that a substrate may be easily and rapidly passed among the loading module <NUM>, the modular unit <NUM>, and the sorting unit <NUM> by a conveyor system <NUM> without exiting the inspection system <NUM>. The loading module <NUM> is configured to load substrates for transfer through the modular unit <NUM> and the sorting unit <NUM> by a conveyor system <NUM>.

The loading module <NUM> receives one or more cassettes <NUM>, <NUM> containing substrates <NUM> in a stacked configuration. Each cassette <NUM>, <NUM> include a plurality of slots therein. Each slot is configured to hold a substrate <NUM>. The cassettes <NUM>, <NUM> may be positioned such that the substrates <NUM> are positioned one over the other. In another example, the substrates <NUM> may be positioned in a holder such that there is no gap between each substrate <NUM>. The substrates <NUM> are transferred from the cassettes <NUM>, <NUM> to the conveyor system <NUM>. The cassette <NUM> is positioned in a cassette holder <NUM>. The cassette <NUM> is positioned in a cassette holder <NUM>. In one embodiment, the conveyor system <NUM> may be a continuous conveyor belt running through the inspection system <NUM>. In another embodiment, the conveyor system <NUM> may include more than one conveyor belt running through the inspection system <NUM>. The one or more conveyor belts may be disposed sequentially in a linear arrangement to transfer substrates received in the loading module <NUM> to the modular unit <NUM>.

The loading module <NUM> includes a plurality of arms (shown for example as arms <NUM>, <NUM>), a plurality of rotatable support members <NUM>, <NUM>, and at least one actuator <NUM> for rotating the arms <NUM>, <NUM>. The arm <NUM> includes a first end <NUM> and a second end <NUM> opposite the first end <NUM>. The arm <NUM> is coupled to the rotatable support member <NUM> at a point located about midway between the ends <NUM>, <NUM> of the arm <NUM>. The rotatable support member <NUM> is configured to rotate the arm <NUM> about an axis <NUM> passing through the point. The arm <NUM> may be seen in more detail in <FIG>.

The arm <NUM> includes a first end <NUM> and a second end <NUM> opposite the first end <NUM>. The arm <NUM> is coupled to the rotatable support member <NUM> at a point located about midway between the ends <NUM>, <NUM> of the arm <NUM>. The rotatable support member <NUM> is configured to rotate the arm <NUM> about an axis <NUM> passing through the point.

The rotatable support members <NUM>, <NUM> are positioned on opposite sides of the conveyor system <NUM>. The rotatable support member <NUM> is positioned between the conveyor system <NUM> and the cassette <NUM>. The rotatable support member <NUM> is positioned between the conveyor system <NUM> and the cassette <NUM>. The rotatable support member <NUM> is positioned to allow the ends <NUM> of the arm <NUM> to be selectively positioned over the cassette <NUM> and the end <NUM> of the arm <NUM> to be selectively positioned over the conveyor system <NUM> to facilitate transfer of substrates therebetween. Likewise, the rotatable support member <NUM> is positioned to allow the end <NUM> of the arm <NUM> to be selectively positioned over the cassette <NUM> and the end <NUM> of the arm <NUM> to be selectively positioned over the conveyor system <NUM> to facilitate transfer of substrates therebetween.

A substrate gripper <NUM> is disposed on each end <NUM>, <NUM>, <NUM>, <NUM> of the arms <NUM>,<NUM>. The gripper <NUM> may be disposed on a bottom side or end of each of the arms <NUM>, <NUM> to allow the gripper <NUM> to secure a substrate <NUM> for transfer. The gripper <NUM> may be any suitable substrate gripper, such as a suction gripper, a claw gripper, a magnetic gripper, a Bernoulli vacuum nozzle, and the like. Each cassette <NUM>, <NUM> may include an elevator (not shown) configured to raise the substrates to a position such that the top most substrate may be grabbed by the substrate gripper <NUM>.

<FIG> is an isometric bottom view of the gripper <NUM> having a Bernoulli vacuum nozzle <NUM>. Bernoulli vacuum nozzle <NUM> The Bernoulli vacuum nozzle <NUM> enables gripping of the substrate with reduced contact, thus advantageously reducing potential damage to the substrate during handling. The Bernoulli vacuum nozzle <NUM> may be operated to provide non-contact transfer of the substrate <NUM> by applying airflow under the substrate <NUM> in a manner that create a vacuum and lift forces between a center and a circumference of the substrate <NUM>. Due to the vacuum force and the continuous airflow, the substrate <NUM> does not attach to the Bernoulli vacuum nozzle <NUM>, but rather holds that substrate <NUM> against one or more stops <NUM>. The stops <NUM> may be configured as a post or other suitable geometry. The stops <NUM> may extend from the arm <NUM> a distance greater than that of the Bernoulli vacuum nozzle <NUM> to ensure that the substrate <NUM> does not contact the Bernoulli vacuum nozzle <NUM> during operation. Ends of stops <NUM>, which contact the substrate <NUM>, may be made of a material selected to provide sufficient friction between the substrate <NUM> and stop <NUM> to ensure that the substrate <NUM> does not shift or slide while the arm <NUM> is rotated. Thus, the gripper <NUM> having the Bernoulli vacuum nozzle <NUM> enables the safe handling of the substrate <NUM> within the loading module <NUM>.

Referring back to <FIG>, the rotatable support members <NUM>, <NUM> may be coupled to the at least one actuator <NUM>. In one embodiment, the support members <NUM>, <NUM> are coupled to the same actuator <NUM>. In another embodiment, each support member <NUM>, <NUM> is coupled to separate actuators <NUM>. As discussed above, the actuator <NUM> is configured to rotate the arms <NUM>, <NUM> about the support members <NUM>, <NUM>. In one embodiment, the actuator <NUM> is a stepper motor, a servo motor, a rotary actuator, an air motor or device suitable. The actuator <NUM> may rotate the rotatable support members <NUM>, <NUM> in indexing fashion, such that with each motion of the arms <NUM>, <NUM>, a new substrate is received from one of the cassettes <NUM>, <NUM> by one end of the arms <NUM>, <NUM> while the opposite end of the arm <NUM>, <NUM> is transferring a substrate to the same position on the conveyor system <NUM>.

The inspection system <NUM> may further include a controller <NUM>. The inspection system <NUM> is coupled to the controller <NUM> by a communication cable <NUM>. The controller <NUM> is operable to control processing of a substrate within the inspection system <NUM>. The controller <NUM> includes a programmable central processing unit (CPU) <NUM> that is operable with a memory <NUM> and a mass storage device, an input control unit, and a display unit (not shown), such as power supplies, clocks, cache, input/output (I/O) circuits, and the like, coupled to the various components of the inspection system <NUM> to facilitate control of the processes of handling and inspecting the substrates. The controller <NUM> may also include hardware for monitoring the processing of a substrate through sensors (not shown) in the inspection system <NUM>.

To facilitate control of the inspection system <NUM> and processing a substrate, the CPU <NUM> may be one of any form of general-purpose computer processors for controlling the substrate process. The memory <NUM> is coupled to the CPU <NUM> and the memory <NUM> is non-transitory and may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk drive, hard disk, or any other form of digital storage, local or remote. Support circuits <NUM> are coupled to the CPU <NUM> for supporting the CPU <NUM> in a conventional manner. The process for loading substrates by operation of the loading module <NUM> may be stored in the memory <NUM>. The process for loading substrates may also be stored and/or executed by a second CPU (not shown) that is remotely located from the hardware being controlled by the CPU <NUM>.

The memory <NUM> is in the form of computer-readable storage media that contains instructions, that when executed by the CPU <NUM>, facilitates the operation of the inspection system <NUM>. The instructions in the memory <NUM> are in the form of a program product such as a program that implements the operation of the inspection system <NUM>, for example, the method <NUM> of <FIG>, including for example the operation of the loading module <NUM>. The program code may conform to any one of a number of different programming languages. In one example, the disclosure may be implemented as a program product stored in computer readable storage media for use with a computer system. The program(s) of the program product define functions of the embodiments. Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media (e.g., read-only memory devices within a computer such as CD-ROM disks readable by a CD-ROM drive, flash memory, ROM chips or any tope of solid-state non-volatile semiconductor memory) on which information is permanently stored; and (ii) writing storage media (e.g. floppy disks within a diskette drive or hard-disk drive or any type of solid-state random-access semiconductor memory) on which alterable information is stored. Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are embodiments of the present disclosure.

<FIG> illustrates a flow diagram of a method <NUM> of loading substrates <NUM> onto the conveyor system <NUM> in the loading module <NUM>, according to one embodiment. The method <NUM> rotates the arms <NUM>, <NUM> in an indexing fashion such that the arms <NUM>, <NUM> simultaneously pick-up one substrate from a cassette <NUM>, <NUM> and load another substrate onto the conveyor system <NUM>. The loading module <NUM> at different stages of method <NUM> are illustrated in <FIG>. <FIG> shows the arms <NUM>, <NUM> in their initial positions.

Method <NUM> begins at block <NUM>. At block <NUM>, an arm of the loading module is rotated a predetermined amount in a first direction, such that an end of the arm is positioned over a first substrate disposed in one of the cassettes. The gripper disposed at the end of the first arm that is positioned over the cassette picks up the first substrate. For example, <FIG> illustrates the first arm <NUM> rotated <NUM> degrees clockwise such that the first end <NUM> of the first arm <NUM> is positioned over the cassette <NUM>. The gripper <NUM> disposed at the first end <NUM> of the first arm <NUM> picks up a first substrate 112a.

At block <NUM>, the first arm <NUM> is rotated a predetermined amount in the first direction such that the end of the arm is no longer positioned over the cassette and the conveyor system. The second arm <NUM> is rotated a predetermined amount in a second direction such that an end of the arm is positioned over a second substrate disposed in the cassette <NUM>. The second direction in which the second arm moves is opposite the first direction in which the first arm moves. By moving the arms <NUM>, <NUM> in opposite directions, the potential for contact between substrates held on the arms is reduced. The gripper disposed on the end of the second arm that is positioned over the cassette picks up a second substrate. In one embodiment, the arms <NUM>, <NUM> are connected to the same actuator. When the arms are connected to the same actuator, the likelihood of the arms colliding is minimized because synchronization of the motion of the arms is ensured. In another embodiment, each arm is connected to a separate actuator. The controller controls the actuators such that the rotation of the arms is timed to prevent the arms or substrates held thereon from colliding. For example, <FIG> illustrates the first arm <NUM> rotated <NUM> degrees clockwise and the second arm <NUM> rotated <NUM> degrees counter clockwise. The first arm <NUM> is in a position substantially perpendicular to the position shown in <FIG> to allow the gripper <NUM> of the second arm <NUM> to rotate and pick up a second substrate 112b from the cassette <NUM>. The first end <NUM> of the second arm <NUM> is positioned over the cassette <NUM>. The second end <NUM> of the second arm <NUM> is positioned over the conveyor system <NUM>.

At block <NUM>, the second arm is rotated a predetermined amount in the second direction, such that the ends of the arm are no longer positioned over the cassette and the conveyor system. The first arm is rotated a predetermined amount in the first direction, such that the end not holding the first substrate is positioned over the cassette. The end of the first arm holding the first substrate is positioned over the conveyor system. The gripper disposed on the end of the first arm holding the first substrate releases the substrate onto the conveyor system. The gripper disposed on the end positioned over the cassette picks up a third substrate. For example, <FIG> illustrates the first arm <NUM> rotated <NUM> degrees clockwise and the second arm <NUM> rotated <NUM> degrees counter clockwise. The first arm <NUM> is in a position substantially perpendicular to the position shown in <FIG> such that the first end <NUM> of the first arm <NUM> is positioned over the conveyor system <NUM> and the second end <NUM> of the first arm <NUM> is positioned over the cassette <NUM>. The gripper <NUM> disposed on the first end <NUM> of the first arm <NUM> is holding the first substrate 112a picked up in <FIG>. The gripper <NUM> disposed on the first end <NUM> of the first arm <NUM> releases the substrate 112a such that the substrate 112a is loaded onto the conveyor system <NUM>. The gripper <NUM> disposed on the second end <NUM> of the first arm <NUM> picks up a third substrate 112c from the cassette <NUM>. The second arm <NUM> is in a position substantially perpendicular to the position of the second arm <NUM> shown in <FIG> to allow rotation of the first arm <NUM> without any collisions.

At block <NUM>, the first arm is rotated a predetermined amount in the first direction, such that the ends of the arm are no longer positioned over the cassette and the conveyor system. The second arm is rotated a predetermined amount in the second direction, such that the end not holding the second substrate is positioned over the cassette. The end of the second harm holding the second substrate is positioned over the conveyor system. The gripper <NUM> disposed on the end of the second arm holding the second substrate releases the substrate onto the conveyor system. The gripper <NUM> disposed on the end positioned over the cassette picks up a fourth substrate. For example, <FIG> illustrates the first arm <NUM> rotated <NUM> degrees clockwise and the second arm <NUM> rotated <NUM> degrees counterclockwise. The second arm <NUM> is in a position substantially perpendicular to the position shown in <FIG>, such that the first end <NUM> of the second arm <NUM> is positioned over the conveyor system <NUM> and the second end <NUM> of the second arm <NUM> is positioned over the cassette <NUM>. The gripper <NUM> disposed on the first end <NUM> of the second arm <NUM> is holding the second substrate 112b picked up in Figure 4B. The gripper <NUM> disposed on the first end <NUM> of the second arm <NUM> releases the substrate 112b such that the substrate 112b is loaded onto the conveyor system <NUM>. The gripper <NUM> disposed on the second end <NUM> of the second arm <NUM> positioned over the cassette <NUM> picks up the fourth substrate 112d. The first arm <NUM> is in a position substantially perpendicular to the position of the first arm <NUM> shown in <FIG> to allow rotation of the second arm <NUM> without any collisions.

Method <NUM> may continue in this matter until all substrates from the cassettes <NUM>, <NUM> are loaded onto the conveyor system <NUM>. Method <NUM> allows for the advantageous loading in excess of <NUM> substrates per hour, which is a significant improvement over conventional inspection systems.

Claim 1:
A loading module (<NUM>) for a substrate inspection system (<NUM>), the loading module comprising:
a first arm (<NUM>) including a first end (<NUM>), a second end (<NUM>) opposite the first end, a first substrate gripper (<NUM>) disposed on the first end of the first arm, and a second substrate gripper (<NUM>) disposed on the second end of the first arm;
a second arm (<NUM>) including a first end (<NUM>), a second end (<NUM>) opposite the first end, a first substrate gripper (<NUM>) disposed on the first end of the second arm, and a second substrate gripper (<NUM>) disposed on the second end of the second arm;
a first rotatable support member (<NUM>) coupled to the first arm;
a second rotatable support member (<NUM>) coupled to the second arm;
a conveyor system (<NUM>) including a conveyor belt disposed between the first and second rotatable support members; and
at least one actuator (<NUM>) coupled to the first and second rotatable support members, and characterized in that
the at least one actuator is configured to rotate the first arm about the first rotatable support member and the second arm about the second rotatable support member to selectively position the first and second substrate grippers of the first and second arms over the conveyor system in a same substrate release location, wherein the substrate release location is a location that allows a substrate held by any one of the first and second substrate grippers of the first and second arms to be released onto the conveyor belt of the conveyor system,
wherein the first arm is configured to be in a position substantially perpendicular to a position of the second arm.