JP2008141141A - Test piece transportation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer transportation system allowing the precise inspection of wafers or the like to be performed in manufacturing in line without largely changing a manufacturing process. <P>SOLUTION: A test piece transportation system is used for a manufacturing process of semiconductor test pieces W such as wafers, and provided with a transportation mechanism 2 for transporting the semiconductor test piece W from one process location to the other process location and an SEM 3 provided on a transportation path of the transportation mechanism 2. The system is formed in such a manner as to temporarily stop the transfer of the semiconductor test piece W by the transportation mechanism 2 at an analyzing position P that is set in the transportation path and perform analyzing inspection by the SEM 3 at the stopping time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transfer system used in a sample manufacturing process for semiconductors and the like.

In a mass production process of semiconductor wafers and liquid crystal substrates (hereinafter also referred to as semiconductor samples), as shown in Patent Document 1, semiconductor samples are manufactured one after another by a transport mechanism from one process chamber to another process chamber. Is done. By the way, in the recent progress of microfabrication of such semiconductor samples, since a high-precision inspection is required even during inspection during the manufacturing process, a scanning electron microscope such as a CD-SEM is often used. It is coming. In that case, conventionally, an SEM is arranged separately from the production line, and a part of wafers and the like are extracted from a lot for which a certain process is completed and inspected.
Japanese Patent Laid-Open No. 2003-174069

  However, in such a system, since it is a sampling inspection, it is necessary to perform an inspection after lot production. If a defect is found in the inspection, the entire produced lot must be discarded. . In addition, when extracting, there is a problem that the manufacturing process must be partially changed.

  The present invention has been made in view of such inconveniences, and by attaching a SEM to a transport mechanism for manufacturing a semiconductor sample, precise inspection of a wafer or the like can be performed without greatly changing the manufacturing process. The main objective of the present invention is to provide a semiconductor sample transport system that can be performed in-line.

  In order to solve this problem, the present invention provides the following means.

  That is, a semiconductor sample transport system according to the present invention includes a transport mechanism for transporting the semiconductor sample from one process place to another process place, and an SEM provided on a transport path by the transport mechanism, and the transport At the analysis position set in the middle of the path, the movement of the semiconductor sample by the transport mechanism is temporarily stopped, and the analysis inspection by the SEM is performed when the movement is stopped. The process place includes a place such as a storage container where temporary storage is performed in addition to a process chamber where a film forming process and a cleaning process are performed.

  On the other hand, since the wafer is held in a transfer mechanism that is not completely fixed, even if the movement of the wafer is stopped at the analysis position and the apparent stationary state is maintained, speaking at the resolution level by SEM, The vibration at the time of stoppage is not settled, or slight vibration from the drive part of the transport mechanism is transmitted, and such vibration may adversely affect the analysis by SEM. In order to avoid this, vibration detection means for detecting the vibration of the semiconductor sample held by the transport mechanism at the analysis position, and vibration blurring of the captured image by the SEM based on the vibration detected by the vibration detection means. It is preferable to further include a shake correction unit for correcting.

  In order to be able to inspect a desired location of a semiconductor sample, a position / orientation detection mechanism that detects the position and orientation of the semiconductor sample based on a reference point such as a notch provided at a predetermined location of the semiconductor sample is further provided. Things are desirable.

  According to the present invention configured as described above, since the SEM is installed on the transport path in the semiconductor sample production line, it becomes possible to inspect each semiconductor sample in-line. Therefore, even if a defective semiconductor sample is generated by the inspection, it suffices to stop the production at that time and eliminate the cause of the defect, and a situation where a wafer or the like is wasted like the conventional case. Can be avoided, and the yield can be improved.

  Furthermore, since the present system for performing the inspection process is merely interposed between the manufacturing processes, the manufacturing process is not significantly changed, and further, it is not necessary to perform sampling, etc., so that observation and analysis related to the inspection are simplified.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  The transfer system 1 according to the present embodiment is incorporated between a vacuum process chamber A and another vacuum process chamber B in a mass production type semiconductor manufacturing process system, and is a semiconductor sample as shown in FIG. A transport mechanism 2 for transporting the wafer W between the chambers A and B and an SEM 3 provided on a transport path by the transport mechanism 2 are provided.

  The transport mechanism 2 includes a gripping unit 21 for gripping the wafer W, a drive unit 22 that moves the gripping unit 21, and a control unit 23 that controls the drive unit 22. The drive unit 22 includes a plurality of arms 221, 222, and 223 that are coupled in series so as to be rotatable on the XY plane, and by rotating these, the gripping unit 21 is freely moved in the XY direction. Further, the arm 223 located at the base end is supported by a support shaft (not shown) so as to be movable in the Z direction. With such a configuration, the drive unit 22 can move the gripping unit 21 in the XYZ direction in terms of position. If it says by a 3 degree-of-freedom and attitude | position, it is comprised so that it can move with the 2 degrees of freedom of XY direction. At least the gripping part 21 and the driving part 22 are accommodated in a transfer chamber 4 that can be evacuated. More specifically, the transfer chamber 4 is provided with pre-chambers A1 and B1 that can be evacuated in order to place wafers W before or after the process in the process chambers A and B, respectively. However, the transfer chamber 4 of the present embodiment is bridged between the pre-chambers A1 and B1 while maintaining airtightness with the outside. The transfer mechanism 2 is configured to hold the wafer W placed in the pre-chambers A1 and B1 and transfer the wafer W through the transfer chamber 4 to another process chamber B (A).

  The SEM 3 is provided in the upper part of the transfer chamber 4 and is, for example, a scanning type that irradiates an electron beam downward and analyzes the wafer W passing therethrough.

  Thus, in this embodiment, each wafer W transferred one after another is stopped each time by a command from the control unit 23 for a certain time required for analysis at a predetermined analysis position P set on the transfer path, The wafer W held by the transport mechanism 2 is analyzed and inspected by the SEM 3. In addition, for the analysis position change or adjustment, the control unit 23 may operate the drive unit 22 to move the gripping unit 21 in the XYZ directions as necessary.

  Therefore, according to the transfer system 1 configured as described above, even if a defective wafer W is generated by inspection, the manufacturing may be interrupted at that time to eliminate the cause of the defect, as in the conventional case. It is possible to avoid a situation where a wafer is wasted. Further, since the present system 1 is merely interposed in series between the manufacturing processes of the wafer W, the wafer manufacturing process is not greatly changed.

  The present invention is not limited to the above embodiment. For example, in terms of the resolution level by SEM, the wafer is held by a transfer mechanism that is not completely fixed. Therefore, even if the movement of the wafer is stopped at the analysis position and the apparent stationary state is maintained, the wafer is stopped. The vibration at this time is not settled, or a slight vibration from the drive unit of the transport mechanism is transmitted, and such vibration may adversely affect the analysis by SEM. Therefore, for example, at the analysis position, a vibration detection unit that detects the vibration of the wafer held by the transport mechanism, and a shake correction unit that corrects the vibration blur of the captured image by the SEM based on the vibration detected by the vibration detection unit. And may be further provided.

  A position and orientation detection mechanism for detecting the position and orientation of the semiconductor sample may be provided based on a reference point such as a notch provided at a predetermined location of the semiconductor sample. If it does in this way, based on the information from the position and orientation detection mechanism, it becomes possible to drive the transport mechanism, align the desired part of the semiconductor sample with the electron beam irradiation position by SEM, and analyze it. .

  Furthermore, the inspection object is not limited to a semiconductor sample, but may be another material sample, and the effect of the present invention is particularly remarkable when applied to a mass production line.

  In addition, the present invention can be variously modified without departing from the spirit of the present invention.

1 is a schematic overall view showing a sample transport system in an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Semiconductor sample transfer system 2 ... Transfer mechanism 3 ... SEM
W ... Semiconductor sample (wafer)
P ... analysis position

Claims (3)

It is used in the manufacturing process of semiconductor samples such as wafers,
A transport mechanism for transporting the semiconductor sample from one process place to another process place, and an SEM provided on a transport path by the transport mechanism;
A semiconductor sample transport system configured to temporarily stop movement of a semiconductor sample by a transport mechanism at an analysis position set in the middle of the transport path, and to perform analysis inspection by SEM at the time of the stop. Vibration detecting means for detecting vibration of the semiconductor sample held by the transport mechanism at the analysis position;
The sample transport system according to claim 1, further comprising: a shake correction unit that corrects a shake of the analysis image by the SEM based on the vibration detected by the vibration detection unit.   3. The sample transport system according to claim 1, further comprising a position / orientation detection mechanism for detecting the position and orientation of the semiconductor sample based on a reference point such as a notch provided at a predetermined location of the semiconductor sample.