TWI573664B - Polish machine and detector - Google Patents

Description

Grinding machine and detector

The present invention relates to a sensing technique, and more particularly to a sensing technique for a wafer processing machine.

Chemical polishing processes are a very important process in semiconductor manufacturing. When performing a chemical polishing process, the surface of the wafer needs to be attached to a polishing pad. Next, both the polishing pad and the wafer are rotated at a high speed, and both rotate in the same direction. Since the wafer and the polishing pad rotate at a high speed during the chemical polishing process, the slider event is liable to occur, that is, the wafer slides out of the polishing pad and is damaged. In order to avoid the occurrence of a slider event, a detector is generally disposed on the chemical polishing machine to detect whether the wafer slides out of the polishing pad. Once the detector detects that the wafer has slipped out of the polishing pad, it stops the chemical grinding machine from running.

In general, a single detection beam emitted by a detector used on a chemical polishing machine can be identified under the rated conditions of ambient light intensity. The rated condition is that the light intensity when the ambient light source is white hot light (incandescent light) cannot exceed 5000 lux, and the light intensity when the ambient light source is sunlight cannot exceed 10,000 lux.

Some chemical grinding machines have a black color on the platform and a black color on the back of the wafer. Therefore, when the above chemical grinding machine occurs In the case of a slider event, since the color of the back side of the wafer is very close to the color of the platform, the conventional detector cannot effectively detect the occurrence of the slider event. As a result, the overall wafer process yield is reduced and the cost is increased.

In view of the fact that the conventional detector cannot effectively detect whether a chemical polishing machine with a black color on the platform has a slide event, the present invention provides a detection technology that can be applied to a chemical polishing machine with a black color of the platform. station.

The invention provides a detection module suitable for a machine having at least one platform and a working jig. The work fixture is located on the platform and is used to carry a wafer for a predetermined process. When the preset process is in progress, the work fixture rotates at a high speed, and the detection module of the present invention includes a detector and a detection circuit. The detector can output a detection current and has a light emitting unit and a light sensing unit. The light emitting unit emits a single detection beam to the junction of the platform and the work fixture, and the intensity of the single detection beam is at least greater than a light intensity threshold. In one embodiment, the light intensity threshold is 20000 lux when the white heat source is the ambient light source and 30,000 lux when the solar source is the ambient light source. In addition, the light sensing unit is configured to sense a single detection beam reflected by the platform to generate a detection current. When the wafer slides out of the work fixture during the preset process and interferes with the path of the single detection beam, the detected current will exceed a current threshold. In addition, the detecting circuit can be coupled to the detector to receive the detecting current, and the detecting circuit further has a first contact and a second contact. When the magnitude of the detected current exceeds the current threshold, the detecting circuit shorts the first contact and the second contact so that the two contacts have the same potential.

From another point of view, the present invention also provides a grinding machine table, The device has a first signal terminal and a second signal terminal, and includes at least one platform, a grinding fixture, a detector, a detecting circuit and a control module. The polishing fixture is located on the platform and is used to carry a wafer to perform a grinding process on the wafer. The light emitting unit can output a detecting current and has a light emitting unit and a light sensing unit. The light emitting unit emits a single detection beam to the interface of the platform and the grinding fixture, and the intensity of the single detection beam is at least greater than a light intensity threshold. In one embodiment, the light intensity threshold is 20000 lux when the white heat source is the ambient light source and 30,000 lux when the solar source is the ambient light source. In addition, the light sensing unit is configured to sense a single detection beam reflected by the polishing platform to generate a detection current. When the wafer slides out of the grinding fixture during the polishing process and interferes with the route of the single detection beam, the detection current output by the light sensing unit exceeds a current threshold. In addition, the detecting circuit can be coupled to the detector to receive the detecting current, and the detecting circuit further has a first contact and a second contact respectively coupled to the first signal end of the grinding machine and the first At the second signal end, when the magnitude of the detected current exceeds the current threshold, the detecting circuit shorts the first contact and the second contact so that the two contacts have the same potential voltage signal, so that the first signal end and The second signal terminals have the same potential. The control module stops the operation of the grinding fixture when the potentials of the first signal end and the second signal end are the same.

Since the light intensity of the single detection beam emitted by the detector used in the present invention reaches the above-mentioned light intensity threshold value, if the polishing platform is black, it is still possible to detect whether or not a slider event occurs.

100‧‧‧ machine

102‧‧‧ platform

104‧‧‧ wafer

106‧‧‧Work fixtures

112‧‧‧ Keeper

114‧‧‧ polishing pad

122‧‧‧Detector

124‧‧‧Detection circuit

132‧‧‧Single detection beam

134‧‧‧A single detection beam that is reflected

202‧‧‧Light emitting unit

204‧‧‧Light sensing unit

212, 214‧‧‧Contact end

222‧‧‧ coil group

224‧‧‧Sensor switch

226‧‧‧Metal core

228‧‧‧ coil

232, 234‧‧‧ signal end

242‧‧‧Control Module

Id‧‧‧Detecting current

1 is a schematic diagram of a machine in accordance with an embodiment of the present invention.

2 is a circuit block diagram of the interior of a machine in accordance with an embodiment of the present invention.

1 is a schematic diagram of a machine in accordance with an embodiment of the present invention. Referring to FIG. 1 , the machine 100 provided in this embodiment has at least one platform 102 and one working fixture 106 . The work fixture 106 is configured to carry a wafer 104 and perform a predetermined process. In some embodiments, the work jig 106 rotates at a high speed while the predetermined process described above is in progress. In some embodiments, the material color of the platform 102 is black.

Additionally, in some embodiments, the machine table 100 can be a grinder table, such as a chemical grinder table. Thus, the work fixture 106 is a grind fixture that includes a retainer 112 and a polishing pad 114. The holder 106 is used to contact the back side of the wafer 104 (referred to as "crystal back") and is attached to the polishing pad 114. In contrast, the polishing pad 114 is the surface (ie, the front side) that contacts the wafer 104. When the predetermined process (in this embodiment, the polishing process) is performed, the polishing pad 114 rotates at a high speed in one direction (counterclockwise), and the holder 112 drives the wafer 104 in the same direction as the polishing pad 114. Rotate.

The machine 100 further includes a detector 122 coupled to a detection circuit 124. The detector 122 can emit a single detection beam 132 to the interface of the platform 102 and the work fixture 106. In particular, the light intensity of the single detection beam 132 needs to reach a minimum light intensity threshold. In this embodiment, the light intensity threshold is 20000 lux when the white heat source is used as the ambient light source, and 30000 lux when the sunlight is used as the ambient light source.

2 is a circuit block diagram of the interior of a machine in accordance with an embodiment of the present invention. Please refer to FIG. 1 and FIG. 2 together. In this embodiment, The detector 122 has a light emitting unit 202 and a light sensing unit 204. The light emitting unit 202 is configured to emit the single detecting beam 132, and the light sensing unit 204 senses the single detecting beam 134 reflected by the platform 102, and outputs according to the light intensity of the reflected single detecting beam 134. A detection current Id. Since the light intensity of the single detection beam 132 can reach the light intensity threshold, when the wafer 104 slides out of the work fixture 106 during the polishing process to block the travel path of the reflected single detection beam 134, the light sensing unit 204 The intensity variation of the reflected single detection beam 134 can still be sensed even if the color of the crystal back is very similar to the color of the platform 102. At this time, the light sensing unit 204 outputs a detection current Id exceeding a current threshold.

In this embodiment, the detection circuit 124 can be implemented using a relay circuit. In more detail, the detection circuit 124 has contact terminals 212 and 214 and is coupled to the signal terminals 232 and 234 of the machine 100, respectively. In addition, the detection circuit 124 further includes a coil set 222 and an inductive switch 224. The coil assembly 222 includes a metal core 226 and a coil 228. The coil 228 is wound around the metal core 226, and the first end thereof is coupled to the light sensing unit 204 to receive the detection current Id. In contrast, the second end of the coil 228 is grounded.

When the detection current Id flows through the coil 228, the coil group 222 generates a magnetic field. If the detection current Id exceeds the above current threshold, the magnetic field generated by the coil assembly 222 will also exceed a magnetic threshold. At this time, the inductive switch 224 is turned on in response to the magnetic field generated by the coil group 222 being induced to exceed the magnetic force threshold. If the inductive switch 224 is turned on, the detection circuit 124 shorts the contact terminals 212 and 214 such that the coupled signal terminals 232 and 234 have the same potential.

In addition, the machine 100 also includes a control module 242 that monitors the status of the signal terminals 232 and 234. When the control module 242 finds the signal end 232 When 234 has the same potential, it represents an event that may have a slider. Therefore, the control module 242 stops the operation of the working fixture 106 to prevent the wafer 104 from being damaged during the polishing process.

In some embodiments, when the discovery signal terminals 232 and 234 have the same potential, the control module 242 also controls the transmission of an alert message to notify the operator of the machine 100 to detect an abnormal event. The warning message may be sending a warning message or lighting a warning light.

In summary, since the light intensity of the single detection beam emitted by the detector provided by the present invention can reach the above-mentioned light intensity threshold, the present invention can still be accurately performed when the polishing process occurs. This event is detected, even if the color of the crystal back is very similar to the material color of the platform. As a result, wafer yield can be improved and the cost of wafer damage can be reduced.

100‧‧‧ machine

106‧‧‧Work fixtures

122‧‧‧Detector

124‧‧‧Detection circuit

132‧‧‧Single detection beam

134‧‧‧A single detection beam that is reflected

202‧‧‧Light emitting unit

204‧‧‧Light sensing unit

212, 214‧‧‧Contact end

222‧‧‧ coil group

224‧‧‧Sensor switch

226‧‧‧Metal core

228‧‧‧ coil

232, 234‧‧‧ signal end

242‧‧‧Control Module

Id‧‧‧Detecting current

Claims (5)

A detection module is applicable to a machine having at least one platform and a work fixture, and the work fixture is located on the platform and is used to carry a wafer for a predetermined process, and when The detection module includes a detector for outputting a detection current, and the detector has a light emitting unit. And transmitting a single detection beam to the junction of the working fixture and the platform, wherein the intensity of the single detection beam is at least greater than a light intensity threshold, wherein the light intensity threshold is when the white heat source is used as an ambient light source 20000lux, which is 30,000 lux when the solar light source is used as an ambient light source; and a light sensing unit for sensing a single detection beam reflected by the platform and generating the detection current when the wafer is in the preset process When the working fixture is slid out and interferes with the route of the single detection beam, the detection current exceeds a current threshold; and a detection circuit is coupled to the detector to receive the Detector Measuring current, The detecting circuit further has a first contact end and a second contact end. When the magnitude of the detecting current exceeds the current threshold, the detecting circuit connects the first contact with the second contact. The short circuit causes the two contacts to have the same potential voltage signal. The detecting module of claim 1, wherein the detecting circuit comprises: a coil set having a metal core and having a coil wound on the metal core, wherein one end of the coil is grounded, and One end is coupled to the detector, Receiving the detection current; and an inductive switch having a first switch end and a second switch end respectively coupled to the first contact end and the second contact end, and the inductive switch senses the coil Actuating the generated magnetic field, wherein when the detected current exceeds the current threshold, the magnetic field generated by the coil set exceeds a magnetic threshold, so that the inductive switch is turned on, so that the first switch end and The second switch terminals have the same potential. a grinding machine having a first signal end and a second signal end, and comprising: at least one platform; a grinding jig located on the platform and configured to carry a wafer to perform grinding on the wafer a detector for outputting a detection current, and the detector has: a light emitting unit for transmitting a single detection beam to the interface between the platform and the polishing fixture, and the single The intensity of the detection beam is at least greater than a threshold value of light intensity, wherein the threshold value of the light intensity is 20000 lux when the white heat source is used as the ambient light source, and 30,000 lux when the solar light source is used as the ambient light source; and a light sensing unit is used to sense The single detection beam reflected by the platform generates the detection current, and when the wafer slides out of the polishing fixture during the polishing process to interfere with the route of the single detection beam, the detection current The size of the detection circuit is coupled to the detector to receive the detection current, and the detection circuit further has a first contact end and a second contact end, respectively Coupling the first a signal terminal and the second signal terminal, when the magnitude of the detection current exceeds the power When the flow threshold is used, the detecting circuit shorts the first contact and the second contact so that the first signal end and the second signal end have the same potential; and a control module for controlling The working fixture is activated, and when the potential of the first signal end and the second signal end are the same, the operation of the working fixture is stopped. The grinding machine of claim 3, wherein the detecting circuit comprises: a coil set having a metal core and having a coil wound on the metal core, wherein one end of the coil is grounded and the other end is The sensor is coupled to receive the detection current; and an inductive switch having a first switch end and a second switch end coupled to the first contact end and the second contact end respectively And the sensing switch is activated by sensing a magnetic field generated by the coil group, wherein when the detecting current exceeds the current threshold, the magnetic field generated by the coil group exceeds a magnetic force threshold, so that the sensing switch is turned on. The first switching end and the second switching end have the same potential. The grinding machine of claim 3, wherein the platform is made of a black material.