JP3202976B2 - Device inspection method and device manufacturing method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a process inspection in a device manufacturing method, and relates to a device manufacturing method using a device punching inspection monitor method.

[0002]

2. Description of the Related Art The prior art of a process inspection monitor in a device manufacturing method is disclosed in, for example, a publicly known example (1) of a monthly magazine "Semiconductor World".
It is described by Kunihiro Yagi on pages 172 to 178 of the June 988 issue. It summarizes measurement targets and measurement methods in process quality control in the process.

When inspecting and monitoring the shape after the processing process with a scanning electron microscope (SEM) at a particularly high resolution,
Split the board into small pieces so that it can be mounted on the SEM sample stage,
Remove a small test piece containing the desired location. In this conventional example, one inspection monitor substrate is required for each inspection monitor. Therefore, in a conventional process inspection monitoring method in a device manufacturing method in which a plurality of substrates are processed into various processes by treating a plurality of substrates as one lot, N
Each of the process inspection monitors (N> 2) requires N inspection monitor substrates, and has a disadvantage that the cost per unit device cannot be reduced because the use efficiency of the substrates is reduced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the number of substrates used for an inspection monitor in a case where a plurality of substrates are taken as one lot and devices are manufactured therefrom by various processes. Is to lower the cost of

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to provide a method for manufacturing a device from a plurality of substrates as one lot by various processes using at least one substrate for an inspection monitor. This is achieved by partially punching out the unit device from the inspection monitor substrate for each inspection monitor of the above process, and performing the inspection monitoring using the punched device.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of an inspection monitor substrate having a diameter of 6 inches and a thickness of about 500 μm used in the embodiment. Two unit devices are punched in the inspection monitor substrate 1, and the punched holes 2 and 3 are visible. The size of the unit device is about 2 mm square.

FIG. 2 is a cross-sectional view of a substrate which is formed by scanning the outline of the unit device 4 from the inspection monitor substrate 1 with a focused ion beam 5 of argon (Ar) having a diameter of about 10 μm. FIG. The unit device 4
Prior to the focused ion beam processing, a groove 6 having a width of about 300 μm is selectively formed by chemical etching on the back surface side of the substrate with the contour line shown in FIG. The groove 6 is provided to reduce the processing depth by the focused ion beam. In this embodiment, a unit device is cut out by a combination of focused ion beam processing and chemical etching processing, and the cutting time is several tens of minutes.

As the focused beam, not only ions but also electrons and lasers can be used. In this case, a fluorine or chlorine-based reaction gas is introduced as an etching gas for beam excitation in the vicinity of the surface of the substrate irradiated with the beam. When comparing ions, electrons, and lasers as focused beams, lasers generally have the fastest processing speed under the same beam diameter conditions.
Hereinafter, it becomes slow in the order of ions and electrons. At the minimum processing width, there is a feature that electrons are the smallest and then become smaller in the order of ions and laser.

On the other hand, when partially punching a unit device from an inspection monitor substrate, it is also possible to punch using a combination of a mask pattern forming method using light or a charged particle beam and a dry etching method. In particular, if a low-temperature dry etching method is adopted, the side wall of the punched groove can be made nearly vertical.

The inspection monitor substrate from which the inspection monitor unit device has been punched has a hole, and when the substrate is passed to a subsequent process, the hole may affect the process result. In order to prevent this, the hole was filled with an embedding device having the same size as the unit device. The inspection monitoring unit device itself can be used in the embedding device when the shape is substantially maintained even after the inspection monitoring and there is no contamination. On the other hand, if the shape is not maintained or there is contamination, a dummy unit device having the same size as the unit device in the same village as the substrate is used. This makes it possible to eliminate the influence of the punched holes in the subsequent processing.

FIG. 3 is a schematic explanatory view of a device punching inspection apparatus combining a focused ion beam (FIB) processing section and a scanning electron microscope (SEM) observation section used in the embodiment. The FIB processing unit 7 punches out a unit device from the inspection monitor substrate. When cross-section observation of a unit device is necessary, this cross-section cutting process is also performed by FIB processing
This is performed using FIB in step 7. Only the punched unit device is conveyed to the SEM observation unit 9 with the partition valve 8 opened. The SEM observation section performs observation and inspection of desired locations and monitors the device manufacturing process. If it is necessary to return the unit device to the inspection monitor substrate, the unit device passes through the partition valve 8 again, and
Transported to In the FIB processing unit 7, the unit device is returned and fixed to the original punched hole of the inspection monitor substrate.

The features of the device punching inspection apparatus in which the FIB processing section and the SEM observation section are combined are that the FIB processing and the SEM observation are efficient and that the sample is not exposed to the atmosphere between the FIB processing and the SEM observation. That is, the contamination can be reduced, and a high-precision alignment can be obtained in a short time when the unit device is buried in the original punched hole of the inspection monitor substrate.

In the embodiments described above, the unit device is used as the inspection monitor device (punching device). However, it is needless to say that the unit may be larger or smaller than the unit device.

[0015]

According to the present invention, in a case where a plurality of substrates are manufactured as one lot and a device is manufactured in a plurality of desired processes, a unit device for the inspection monitor is always determined in advance. Since it can be taken out from the substrate (usually one), the number of substrates for the inspection monitor can be reduced, and the cost per unit device can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view of an inspection monitor substrate embodying the present invention.

FIG. 2 is an explanatory view of a cross section of a substrate in which a unit device is punched with a focused ion beam from an inspection monitor substrate according to an embodiment of the present invention.

FIG. 3 shows a focused ion beam (FI) according to an embodiment of the present invention.
B) Schematic explanatory diagram of a device punching inspection apparatus in which a processing unit and a scanning electron microscope (SEM) observation unit are combined.

[Explanation of symbols]

1 ... Inspection monitor substrate, 2, 3 ... Hole punched out of inspection monitor unit device, 4 ... Inspection monitor unit device, 5 ... Focused ion beam, 6 ... Selective formation by chemical etching Groove, 7: FIB processing part, 8: Partition valve, 9: SEM observation part.

──────────────────────────────────────────────────続 き Continued on the front page (56) References Patent 3124541 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/66 H01J 37/31 H01L 21/302

Claims (4)

(57) [Claims] A plurality of substrates are treated as one lot and a plurality of substrates are processed.
Device inspection method when manufacturing device through process
At least one board is detected from the lot.
A step of selecting a substrate for inspection and an inspection for each process
Punching a predetermined area from the substrate for use as a sample;
Inspecting the sample.
Inspection method. 2. The sample punching step is performed by a particle beam.
Processing the substrate for inspection and the chemical etching
Processing a substrate for inspection.
The device inspection method according to claim 1. 3. The method according to claim 1, wherein said particle beam processing step comprises the steps of:
Any one of beam, electron beam or laser beam
3. The device inspection according to claim 2, wherein
Method. 4. The method according to claim 1, wherein the chemical etching process is performed by beam excitation.
3. An etching gas according to claim 2, wherein:
The device inspection method described in the above.