This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2011-20375, filed on Feb. 2, 2011; the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a defect inspection method and a manufacturing method of a semiconductor device.
In a manufacturing process of semiconductor devices, a nanoimprint exposure method attracts attention, in which a mold of a master is transferred onto a transfer target substrate. The nanoimprint method is a method in which a mold of a master (template), on which a pattern to be transferred is formed, is pressed against a resist layer, which is applied to a substrate and is formed of an imprint material, and the resist layer is cured thereby transferring the pattern onto the resist layer.
In this nanoimprint pattern forming method, imprinting is performed by bringing a template and a wafer into close contact with each other, so that breakage or defect of the template occurs accidentally. If the imprint process is continued while leaving such damage or defect of the template, a large number of defective products are generated, so that it is desired to detect damage or defect of the template early.
In general, according to a defect inspection method of embodiments, a conductive layer is formed on a base layer. Next, an imprint pattern is formed on the conductive layer. Next, an electrolytic solution is brought into contact with the imprint pattern. Next, an electrode is brought into contact with the electrolytic solution. Next, voltage is applied between the conductive layer and the electrode. Next, current flowing between the conductive layer and the electrode when the voltage is applied between the conductive layer and the electrode is measured. Next, the presence or absence of a defect of the imprint pattern is determined based on a measuring result of the current.
A defect inspection method according to the embodiments will be explained below with reference to the drawings. The present invention is not limited to these embodiments.
(First Embodiment)
In
Next, an imprint material 4′ is jetted onto the conductive layer 2 via a nozzle 3 by using a method such as an ink jet method. As the imprint material 4′, for example, ultraviolet curable resist can be used. Moreover, the imprint material 4′ may be formed of insulator.
Next, as shown in
Then, the imprint pattern 4 is cured by irradiating the imprint pattern 4 with ultraviolet rays through the template 5 in a state where the template 5 is pressed against the imprint pattern 4.
In the example of
Next, as shown in
Next, as shown in
Then, voltage is applied between the electrodes 7 and 8 via a power supply 9 and current that flows between the electrodes 7 and 8 at that time is measured by an ammeter 10. At this time, because the imprint pattern 4 is formed of insulator, when there is no defect in the imprint pattern 4, current does not flow between the electrodes 7 and 8.
Then, the measured value of the current measured by the ammeter 10 is compared with a threshold, and when the measured value is equal to or lower than the threshold, it is determined that there is no defect in the imprint pattern 4.
Next, as shown in
Then, when it is determined that there is no defect of the imprint pattern 4, the base layer 1 is processed via the imprint pattern 4. As the process performed on the base layer 1, ion implantation may be performed on the base layer 1 via the imprint pattern 4 or the base layer 1 may be etched with the imprint pattern 4 as a mask. Thereafter, the conductive layer 2 and the imprint pattern 4 remaining on the base layer 1 are removed.
In
Next, as shown in
The cause of generation of the defect 12 in the imprint pattern 4, for example, includes poor filling (dust or resist stripping at the time of releasing) of resist, air bubble, microbubble, ink jet bubble, clogging of the template recess portion by foreign matter, and foreign matter on a wafer substrate.
Next, as shown in
Next, as shown in
When it is determined that there is a defect in the imprint pattern 4, the subsequent processes are stopped, so that a large number of defective products can be prevented from being generated.
In
Next, electrolytic solution is applied to the inspection area by an ink jet method (S2). In the ink jet method, the inspection area can be specified for each area of one droplet and, for example, the area of one droplet can be 20 μmΦ).
Next, a template counter electrode for electrode is prepared (S3) and voltage is applied between the template electrode and the counter electrode (S4).
Next, the template electrode is arranged on the electrolytic solution (S5) and current between the template electrode and the counter electrode is monitored (S6). The template electrode may be arranged on the electrolytic solution only by its own weight. The presence or absence of a defect of the imprint pattern is determined based on the monitor result of the current between the template electrode and the counter electrode (S7).
(Second Embodiment)
In
Then, the electrode 7 is brought into contact with the electrolytic solution 6 while moving the electrode 7 for each of the shot areas Sh1 to Sh4 to measure current flowing between the electrodes 7 and 8 by the ammeter 10 for each of the shot areas Sh1 to Sh4. Then, the measured value of the current measured by the ammeter 10 is compared with a threshold for each of the shot areas Sh1 to Sh4 to determine the presence or absence of a defect of the imprint pattern 4 for each of the shot areas Sh1 to Sh4.
Consequently, the presence or absence of a defect of the imprint pattern 4 can be determined for each of the shot areas Sh1 to Sh4, enabling to make it easy to determine the cause of generation of a defect of the imprint pattern 4.
In
In
In
(Third Embodiment)
In
Then, the electrode 7 is brought into contact with the electrolytic solution 6 while moving the electrode 7 for each of the shot areas Sh1 to Sh4 to measure current flowing between the electrodes 7 and 8 by the ammeter 10 for each of the shot areas Sh1 to Sh4. Then, the measured value of the current measured by the ammeter 10 is compared with a threshold for each of the shot areas Sh1 to Sh4 to determine the presence or absence of a defect in a specific portion of the imprint pattern 4 for each of the shot areas Sh1 to Sh4.
Consequently, the presence or absence of a defect of the imprint patterns 4 can be determined for each circuit function, enabling to make it easy to determine the cause of generation of a defect of the imprint pattern 4.
For example, a position in the imprint pattern 4, at which a defect is generated, can be narrowed by performing the defect inspection on the imprint patterns 4 by the method in
In
(Fourth Embodiment)
In
In each of the imprint stages 25-1 to 25-n, the nozzle 3 in
Then, the wafer W on which the conductive layer 2 is formed is conveyed to the wafer temperature controlling stage 22 to be subjected to temperature control and thereafter, the wafer W is conveyed to the pre-alignment stage 23. Then, the wafer W is conveyed to a free stage among the imprint stages 25-1 to 25-n via the pre-alignment stage 23 to be subjected to the imprint process, so that the imprint pattern 4 is formed on the conductive layer 2, and the wafer W is conveyed from a stage, in which the imprint process is finished, among the imprint stages 25-1 to 25-n to the in-line inspection stage 26. Then, the in-line inspection is performed in the in-line inspection stage 26 and current leakage in the imprint pattern 4 on the conductive layer 2 is monitored.
Then, the wafer W, on which the in-line inspection is performed, is conveyed out of the in-line inspection stage 26, and if the wafer W inhibits conveyance of the wafer W into the imprint stages 25-1 to 25-n, the wafer W is temporarily retracted to the retraction stage 24 via the pre-alignment stage 23.
Moreover, in the in-line inspection device 27, the presence or absence of a defect of the imprint pattern 4 is determined based on the current leakage amount and the presence or absence of a defect is registered for each wafer W. Then, in the control device 28, a stage, in which the imprint process is performed on the wafer W having a defect, is specified from among the imprint stages 25-1 to 25-n and the use of the stage among the imprint stages 25-1 to 25-n is suspended.
Consequently, one in-line inspection stage 26 can be shared by a plurality of the imprint stages 25-1 to 25-n, so that the operating rate of the in-line inspection stage 26 can be improved and the in-line inspection can be performed while shortening the standby time after the imprint process. Thus, it is possible to reduce the risk of generating a large number of defective products in the mass production.
(Fifth Embodiment)
In
Then, after applying the electrolytic solution 6 to each of the shot areas Sh1 to Sh4 by an ink jet method, the electrode 31 is brought into contact with all of the electrolytic solutions 6 in a plurality of the shot areas Sh1 to Sh4 collectively to measure current flowing between the electrodes 31 and 8 by the ammeter 10. Then, the measured value of the current measured by the ammeter 10 is compared with a threshold to determine the presence or absence of a defect of the imprint patterns 4 collectively for a plurality of the shot areas Sh1 to Sh4.
Consequently, the presence or absence of a defect of the imprint patterns 4 can be determined for a plurality of the shot areas Sh1 to Sh4 in one current measuring process, so that the time required for the defect inspection process can be shortened.
(Sixth Embodiment)
Whereas the imprint pattern 4 is separated for each of the shot areas Sh1 to Sh4 in the defect inspection method in
After applying the electrolytic solution 6 continuously over the shot areas Sh1 to Sh4 by an ink jet method, the electrode 31 is brought into contact with the electrolytic solution 6 to measure current flowing between the electrodes 31 and 8 by the ammeter 10. Then, the measured value of the current measured by the ammeter 10 is compared with a threshold to determine the presence or absence of a defect of the imprint pattern 4 collectively for a plurality of the shot areas Sh1 to Sh4.
Consequently, the presence or absence of a defect of the imprint pattern 4 can be determined for a plurality of the shot areas Sh1 to Sh4 in one current measuring process without separating the electrolytic solution 6 for each of the shot areas Sh1 to Sh4, so that the time required for the defect inspection process can be shortened.
(Seventh Embodiment)
In
After applying the electrolytic solution 6 to each of the shot areas Sh1 to Sh4 by an ink jet method, the electrodes 31-1 to 31-4 are brought into contact with the electrolytic solutions 6 in the shot areas Sh1 to Sh4, respectively. Then, while sequentially switching between the electrodes 31-1 to 31-4 by the switching unit 34, current flowing between each of the electrodes 31-1 to 31-4 and the electrode 8 is measured by the ammeter 10. Then, the measured value of each current measured by the ammeter 10 is compared with a threshold to determine the presence or absence of a defect of the imprint pattern 4 for each of the shot areas Sh1 to Sh4.
Consequently, the presence or absence of a defect of the imprint pattern 4 can be determined for each of the shot areas Sh1 to Sh4 in a state where the positions of the electrodes 31-1 to 31-4 are fixed, enabling to make it easy to determine the cause of generation of a defect of the imprint pattern 4 while shortening the time required for a process.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
Number | Date | Country | Kind |
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2011-020375 | Feb 2011 | JP | national |