KR19990070081A - Semiconductor metrology system and method for reducing wafer loading time - Google Patents

Abstract

When measuring wafers processed by the semiconductor metrology system, the wafers are loaded by preloading the wafers into the semiconductor metrology system so that the waiting time of subsequent wafers is shortened so that the wafers are loaded immediately after the finished wafers are unloaded. Disclosed are a semiconductor metrology system and method for shortening the loading time required for loading.

According to the present invention, there is provided a method for loading a wafer having completed a preceding process into a measurement facility, the method comprising: determining whether the wafer to be measured is waiting by the measurement facility; Loading all of the subsequent metrology wafers that are waiting in the rest of the pre-alignment section, exchanging positions of the wafers measured by the metrology facility and subsequent metrology wafers to be measured, and Unloading from the draw and reloading the subsequent metrology wafer that is unloaded and waiting on the empty align line.

Description

Semiconductor metrology system and method for reducing wafer loading time

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor metrology system and method for shortening the wafer loading time, and more particularly to a semiconductor metrology system in order to shorten the waiting time of subsequent wafers when measuring wafers processed by the semiconductor metrology system. The present invention relates to a semiconductor metrology system and method for reducing the loading time required to load a wafer by loading the wafer after the wafer has been loaded in advance and unloaded after the measurement.

In general, the development of semiconductor products widely applied to various industrial fields is rapidly progressing in order to meet their application ranges and demands, and in recent years, the miniaturization of semiconductor products, that is, the electric devices are used in smaller chips. There is a growing interest in technology that is heavily integrated.

In order to produce such highly integrated semiconductor products, a semiconductor facility for precisely performing various semiconductor manufacturing processes and semiconductor manufacturing processes is required.

In order to carry out the process, such a semiconductor device has tolerances and precisions in micro (μ) and angstrom (Å) units, and therefore it is necessary to measure how precisely the desired process is actually performed.

For this reason, after the process is completed from almost all semiconductor equipment, the semiconductor product measuring system performs a measurement before transferring the semiconductor product to a subsequent process.

1 is a conceptual diagram conceptually showing such a conventional semiconductor measurement system 100.

Referring to FIG. 1, the semiconductor metrology system 100 includes two wafer cassettes (or wafer loaders) 5 on which semiconductor products (hereinafter referred to as wafers) to be measured as a whole are loaded, and a pattern of the wafers 4 is constant. A measurement unit configured to load the aligning unit 20 for aligning the flat zone of the wafer 4 so as to face the wafer 4 and the wafer 4 aligned with the aligning unit 20 to perform measurement ( 10).

At this time, the wafer 4 of the wafer cassette 5 is loaded / unloaded by the robot arm 30 into the aligner 20, and the robot arm 30 is also loaded from the aligner 20 to the measurement unit 10. The wafer 4 is loaded / unloaded by this.

A method of loading and measuring the wafer 4 in the semiconductor metrology system 100 having such a configuration and then unloading it will be described with reference to the flowchart of FIG. 2.

Referring to the accompanying flowchart, the wafer cassette 5 on which the wafer 4 processed in the semiconductor facility is loaded is transferred to the semiconductor measurement system 100 to determine whether the wafer 4 to be measured exists ( step 10).

At this time, if the wafer 4 to be measured does not exist, the semiconductor measurement system 100 enters a standby state (step 15). If the wafer 4 to be measured exists, after confirming the wafer ID, the checked wafer 4 is checked. The robot arm 30 moves to the aligner 20 (step 20).

The wafer 4a (indicated by a hidden line) transferred to the aligner unit 20 is aligned with each chip pattern formed on the wafer 4a in the aligner unit 20, wherein the alignment of the wafer 4a is a wafer. Based on the flat zone of (step 30).

The wafer 4a on which the alignment has been completed is transferred to the measurement system again by a robot arm (not shown) and is ready to perform measurement (step 40).

Thereafter, measurement is performed on the wafer 4a transferred by the measurement unit 10 (stpe 50). At this time, as the measurement element, the thickness uniformity of the thin film, the state of the thin film, and other defective elements are measured.

After the measurement is completed, the wafer 4a is again taken out by the robot arm to the empty aligning unit 20 (step 60), and then transferred to the wafer carrier 5 again, and is waiting in the wafer cassette 5. Subsequent wafer 4 will repeat this process.

However, when measuring the various elements of the wafer which completed the previous process by such a conventional semiconductor measurement system, there existed the following problem.

As a problem, after the wafer 4a to be measured is aligned in the aligning unit 20, the aligning unit 20 becomes blank until it is transferred to the measuring unit 10 and the measurement is completed. After the wafer 4a has been unloaded into the wafer cassette 5, the subsequent wafer 4, which is in standby, is transferred to the aligner 20 again, and the loading time is delayed by the time that the aligner 20 is empty. There was a problem that the production time is increased according to the production as a whole, the expensive equipment efficiency is lowered.

Accordingly, the present invention has been made in view of such a conventional problem, and an object of the present invention is to provide an empty alignment portion when the wafer to be measured is aligned by the alignment portion and then transferred to the measurement portion for measurement. It is possible to shorten the loading time of the wafer loaded into the semiconductor metrology system by maximizing the time that the wafer is loaded for measurement by transferring the wafer that is waiting in the wafer, and switching the wafer that has been measured and the wafer in the waiting state by switching.

1 is a conceptual diagram conceptually showing a conventional semiconductor metrology system;

2 is a flowchart showing wafer measurement by a conventional semiconductor measurement system.

3 and 4 are conceptual views conceptually showing a semiconductor metrology system in which wafer loading time according to the present invention is shortened.

5 is a flow chart illustrating a method of shortening the time for loading a wafer into a semiconductor metrology system according to the present invention.

The semiconductor metrology system which has shortened the wafer loading time for achieving the object of the present invention includes a wafer cassette in which a plurality of wafers for which a preceding process is completed is loaded, a measurement unit for measuring a wafer, and a wafer to be measured into the measurement unit. To the load and rod interconnecting the measurement wafer front line portion and the waiting wafer front line portion, which are loading subsequent wafers to be measured from the wafer cassette, And a wafer exchanger having a rod rotating device which is formed to rotate the measurement wafer align line portion and the standby wafer align line portion.

Preferably, at least two measurement wafer aligners and at least two atmospheric wafer aligners are provided.

Preferably, the end portion of the rod is coupled to correspond to the measurement wafer align line portion and the standby wafer align line portion.

Preferably, in the method of loading the wafer having finished the preceding process into the measurement facility, determining whether the wafer to be measured is waiting by the measurement facility, and loading the wafer to be measured to any one of a plurality of aligners. Loading the remaining measurement wafers waiting for the remaining aligning portion, replacing positions of the wafer measured by the measurement facility with the subsequent measurement wafer to be measured, and removing the measured wafers from the aligning portion. And unloading and reloading the subsequent metrology wafers that are unloaded and waiting on the empty align line.

Preferably, the measuring wafer and the measured wafer are performed by the robot arm in the step of loading the measuring wafer and the measured wafer into the aligning portion.

Hereinafter, a semiconductor measurement system and a method for reducing the wafer loading time of the present invention will be described in detail with reference to the accompanying drawings.

The semiconductor measuring equipment, which has reduced the wafer loading time, measures the first A wafer out of the 25 wafers when the wafer cassette loaded with about 25 wafers having completed the preceding process before the measurement is moved to the measuring equipment. The accuracy of the measurement is verified based on the measurement result. Once the accuracy of the measurement is verified, the measurement is also performed on all wafers loaded on the wafer carrier of the wafer B or smaller.

A semiconductor metrology system that shortens the wafer loading time for such an operation will be described with reference to the accompanying drawings.

The semiconductor metrology system which shortens the wafer loading time according to the present invention includes a wafer cassette (or wafer loader; 160) in which 25 wafers having finished the preceding process are loaded as shown in FIGS. 3 to 5; The robot arm 130 transfers the single wafer 140 from the wafer cassette 160, and the robot arm 130 transfers and aligns the wafer 140 from the wafer cassette 160 by the robot arm 130. It includes an alignment unit 154, 156, and a measurement unit 170 for performing measurement by loading the wafer 140 from the aligner unit 154, 156. In the present invention, two aligning units are preferably used.

In addition, a wafer exchanger is provided for switching the subsequent wafers 140a loaded on the aligners 154 and 156 and waiting for measurement and the wafers 140b on which measurement is completed from the measurement unit 170 in a switching manner.

In more detail, the wafer exchanger is composed of a rod 150 having a predetermined length and a rod rotating device 152 that rotates the rod 150 by 180 ° at the center of the rod 150.

Freight lines 154 and 156 are formed at both ends of the rod 150 of the wafer exchange unit. Among them, the framing portion formed at one end of the rod is defined as the first framing portion 154, and the other framing portion is defined as the second framing portion 156.

The A wafer 140b to be measured first is loaded in the first aligner 154 formed at one end of the rod 150, and the second aligner 165 formed at the other end of the rod 150 is loaded in the first aligner 154. After the A wafer 140b is measured, the B wafer 140a waiting to be measured is loaded.

As described above, the first aligning unit 154 and the second aligning unit 156 on which the A and B wafers 140b and 140a are loaded are rotated by 180 ° by the rod rotating device 152 and the measurement is completed. The wafer 140b and the B wafer 140a waiting to be measured are configured such that their positions are replaced by a switching method.

4 shows an easy process of replacing the A wafer 140b and the B wafer 140b with each other. Referring to the accompanying flowchart, a method for shortening the loading time by the semiconductor metrology system having reduced the wafer loading time configured as described above is as follows.

First, the measurement facility system 200 determines whether the wafer 140, which has completed the preceding process by the semiconductor facility, is waiting for measurement while being loaded on the wafer cassette 160 (step 100). If 140 is not present, the metrology system 200 is in a standby state (step 115).

If the wafer to be measured (defined as an A wafer; 140b) exists, the measurement facility system 200 checks the ID of the A wafer 140b to be measured, and then uses the first wafer 154 of the wafer exchange unit as an A wafer ( 140b) (step 120).

When the A wafer 140b is transferred to the first aligner 154, the first aligner 154 aligns the pattern of the A wafer 140b constantly (step 130). In this case, the first prealignment unit 154 performs alignment by referring to the flatzone of the A wafer 140b.

When the alignment of the A wafer 140b is completed by the first alignment unit 154, the wafer exchange unit drives the rotating device 152 at a predetermined angle so that the first alignment unit 154 is rotated to measure the measurement unit 170. The second aligner 156 of the wafer exchanger, which was loaded inside the measurement unit 170, is moved to the position of the first aligner 154. That is, the positions of the first aligner 154 and the second aligner 156 are replaced.

Thereafter, the A wafer 140b aligned to the first aligner 154 is measured by the measuring unit 170 (step 140).

At the same time, the semiconductor metrology system 200 defines a wafer to be subsequently measured (defined as a B wafer; if there is 140a), the B wafer 140a is loaded into the second prealignment unit 156 and aligned (step 150). .

Subsequently, the measurement is terminated on the A wafer 140b that is aligned with the first framing unit 154 loaded on the measuring unit 170 (step 160), and the B wafer (with the second framing unit 156). When the alignment of 140a is completed, the wafer exchange unit is driven to replace the positions of the first aligner 154 and the second aligner 156 (step 170).

As the positions of the first aligning unit 154 and the second aligning unit 156 are exchanged as described above, the A wafer 140b and the B wafer 140a waiting to be measured are replaced by a switching method. The B wafer 140a is loaded back into the measurement unit 170 and the measurement proceeds, and the A wafer 140a having completed the measurement is again unloaded into the wafer cassette 160 by the robot arm 130.

Subsequently, in the vacant position of the A wafer 140a unloaded from the first aligning unit 154 to the wafer cassette 160, the wafers C, D, E ... n waiting for subsequent measurement are replaced by a switching method. While repeating loading and unloading, the loading time for measuring the wafer 140 can be shortened.

In the present invention, although the first pre-alignment unit 154 for aligning the wafer to be measured and loaded in the measurement unit 170 and the second pre-alignment unit 156 for aligning the wafer to be measured are used, In order to increase the efficiency of the measurement equipment, a plurality of aligners 158 may be used as shown in FIG. 5.

As described in detail above, while the measurement equipment is performing the measurement of the wafer which has completed the preceding process, the measurement equipment is preloaded with the subsequent measurement wafer in advance, and the wafer to be measured and the wafer to be measured are alternated by banking. Since the measurement is performed continuously, the measurement time is reduced, thereby reducing the production air of the semiconductor product.

Claims (5)

A wafer cassette for storing a plurality of wafers of which a preceding process is completed; A measurement unit for measuring the wafer; A measurement wafer pre-alignment unit for loading the wafer to be measured in the measurement unit in an aligned state, a standby wafer pre-loading unit for loading subsequent wafers to be measured from the wafer cassette, and a measurement wafer pre-alignment unit and the atmosphere And a wafer exchanger having a rod interconnecting a wafer aligning portion and a rod rotating device formed on the rod to rotate the measuring wafer aligning portion and the standby wafer aligning portion to rotate positions. A semiconductor metrology system that reduces wafer loading time. 2. The semiconductor metrology system according to claim 1, wherein the measurement wafer aligning portion and the standby wafer aligning portion are at least two or more. 3. The semiconductor metrology system according to claim 2, wherein the measurement wafer aligning portion and the end portion of the rod are coupled to correspond to the standby wafer aligning portion. A method of loading a wafer having completed a preceding process into a measurement facility, the method comprising: determining whether a wafer to be measured is waiting by the measurement facility, and loading the wafer to be measured to any one of a plurality of align lines. And loading all of the subsequent measurement wafers waiting in the remaining aligning section, replacing the positions of the wafer measured by the measurement facility with the subsequent measurement wafer to be measured, and And unloading from the alignment unit and reloading the subsequent metrology wafer which is unloaded and waiting in the empty alignment unit. 5. The method of claim 4, wherein the measuring wafer and the measured wafer are performed by a robot arm in the step of loading the measuring wafer and the measured wafer into the align portion.