JP3460064B2 - Defect inspection method of master information carrier and magnetic film pattern magnetic transfer method using master information carrier - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a master information carrier disk for defects on a magnetic recording medium used in a hard disk apparatus or a floppy disk apparatus. The present invention also related to the magnetic film pattern magnetic transfer method of the master information carrier used.

[0002]

2. Description of the Related Art At present, a magnetic recording / reproducing apparatus tends to have a high recording density in order to realize a small size and a large capacity.

In the field of hard disk drives, which are typical magnetic disk devices, the areal recording density has already reached 1
Devices exceeding 0 Gbit / sqin have been commercialized, and one year later, the areal recording density is 20 Gbit / sqin.
It is recognized that the technological progress is so rapid that it is expected that the device will be put to practical use.

The technical background that enables such a high recording density is due to the magnetoresistive element type head capable of reproducing a signal having a track width of only a few μm with good SN while improving the linear recording density. Is large.

Further, as the recording density is increased, it is also required to reduce the flying height of the floating magnetic slider with respect to the magnetic recording medium, and there is an increased possibility that the disk / slider may come into contact with the flying magnetic slider for some reason during the flying. ing. Under such circumstances, the recording medium is required to have a higher smoothness.

In order for the head to scan a narrow track accurately, the head tracking servo technique plays an important role. In a current hard disk drive using such a tracking servo technique, a tracking servo signal, an address information signal, a reproduction clock signal, etc. are recorded on a magnetic recording medium at regular angular intervals. The drive device detects and corrects the position of the head based on these signals reproduced from the head at regular time intervals, thereby enabling the head to accurately scan the track.

Here, as described above, the servo signal, the address information signal, the reproduction clock signal, and the like serve as reference signals for the head to accurately scan the track, so that the writing (formatting) is not performed. High positioning accuracy is required. In the current hard disk drive, formatting is performed by positioning the recording head using a dedicated servo device (servo writer) incorporating a high-precision position detection device using optical interference.

However, there are the following problems in the formatting by the servo writer.

First, the recording by the magnetic head is basically line recording based on the relative movement between the magnetic head and the magnetic recording medium, and since it is necessary to write a signal over many tracks, the method by the servo writer is not used. In addition, it takes a lot of time to perform preformat recording, and a plurality of expensive dedicated servo writers are required to increase productivity, and preformat recording is expensive.

Secondly, a large amount of cost is required to introduce and maintain many servo writers.

These problems became more serious as the track density increased and the number of tracks increased.

Therefore, the formatting is not performed by the servo writer, but the master information carrier on which all the servo information has been written in advance and the magnetic disk to be formatted are superposed, and transfer energy is externally applied to the master. A method of collectively transferring servo information to a magnetic disk has been proposed.

As an example thereof, Japanese Unexamined Patent Publication No. 10-40544
An example is the magnetic transfer device disclosed in the publication.

In this publication, a magnetic portion made of a ferromagnetic material is formed on the surface of a substrate in a pattern shape for an information signal to form a master information carrier, and the surface of this master information carrier is
Contacting the surface of a sheet-shaped or disk-shaped magnetic recording medium on which a ferromagnetic thin film or a ferromagnetic powder coating layer is formed,
A method of recording a magnetic pattern having a pattern shape corresponding to an information signal formed on a master information carrier on a disk-shaped magnetic recording medium by applying a predetermined magnetic field is disclosed.

[0015]

By the way, in the recording of an information signal using such a conventional magnetic transfer device, a disk-shaped magnetic recording medium having an array pattern corresponding to the information signal provided on the master information carrier as a magnetization pattern. However, it is important to uniformly and stably record high-density information signals over the entire surface of the disk-shaped magnetic recording medium.

However, in the above-mentioned conventional magnetic transfer apparatus, when an abnormal protrusion or a foreign substance is present on the surface of the master information carrier at the time of magnetic transfer, the two contact with each other to cause the surface of the disk-shaped magnetic recording medium to contact. Depression part occurs.

FIGS. 26 (a) and 26 (b) show a disk-shaped magnetic recording medium when an abnormal protrusion or foreign matter is present on the surface of the master information carrier during magnetic transfer in the conventional magnetic transfer method. Surface of disk-shaped magnetic recording medium after magnetic transfer by contact with a master information carrier (see symbol a)
FIG. 3 is a diagram showing a center circle, which is a depressed portion (see reference numeral b) caused by a foreign substance interposed between the master information carrier and the disk-shaped magnetic recording medium. Minute protrusions (see reference numeral c) due to the recoil occur in the immediate vicinity of the depressed portion. FIG. 26 (a) is a photograph, and a schematic diagram is shown in FIG. 26 (b) in correspondence with the fact that this is unclear. In addition, FIG.
[Fig. 4] is a diagram in which a cross section of this depression is measured.

In FIG. 27, it can be seen that minute projections (see reference numeral c) of about 20 nm are present around the depressed portion (see reference numeral b) which is recessed from the surface of the disk-shaped magnetic recording medium by about 50 nm.

Here, as described above, the flying height of the floating magnetic slider from the surface of the disk-shaped magnetic recording medium is usually about 20 nm, whereas, on the other hand, the floating amount on the disk-shaped magnetic recording medium is 20 nm as shown in FIG. If there is a minute protrusion, the magnetic head and the disk-shaped magnetic recording medium may come into contact with each other during data recording / reproduction. In such a case, the magnetic head is skipped at the moment of contact, and the magnetic head and the disk-shaped magnetic recording medium are ejected. The clearance of the medium becomes large, the signal recording / reproducing performance deteriorates, and the magnetic head physically contacts the disk-shaped magnetic recording medium,
This has been a cause of shortening the life of the magnetic head and possibly causing damage to the disk-shaped magnetic recording medium itself.

FIG. 28 shows the state of protrusions on the entire surface of the disk-shaped magnetic recording medium after magnetic transfer when abnormal protrusions or foreign substances are present on the surface of the master information carrier during magnetic transfer. The results of the optical measurement are shown, and it can be seen that protrusions of 20 nm or more exist on the surface of the disk-shaped magnetic recording medium.

As described above, when an abnormal protrusion or a foreign substance is present on the surface of the master information carrier during magnetic transfer, the disk-shaped magnetic recording medium is brought into contact with the master information carrier to perform magnetic transfer, Since the depressions are present on the disk-shaped magnetic recording medium after magnetic transfer, there is a problem that the recording / reproducing performance and the life of the magnetic head are reduced. This problem becomes more and more serious as the flying height between the magnetic head and the disk becomes smaller with the future increase in recording density.

However, since the pattern shape for the information signal is formed on the surface of the master information carrier, it is extremely difficult to directly inspect the abnormal protrusions and foreign matters existing on the master information carrier in a short time. This is because the presence of the pattern shape hinders detection of abnormal protrusions and foreign matter.

As a method of avoiding this problem, a method has been devised in which the surface of the master information carrier is not directly inspected, but defects on the surface of the magnetic recording medium after magnetic transfer are performed by an optical method. However, in the conventional method, when trying to discriminate even minute abnormal protrusions existing on the master information carrier, the medium for magnetic transfer needs to be extremely smooth, which causes a problem of cost increase.

This is because if the medium for magnetic transfer is not ultra-smooth, defects will exist in the medium even before magnetic transfer, so that the defects caused by the master information carrier can be accurately determined. Because it is difficult.

When a small defect caused by the master information carrier occurs, the defect of the disk-shaped magnetic recording medium caused by this always occurs due to magnetic transfer. Therefore, even if the defect is very small. It was a big problem.

[0026] The present invention has been made in view of the above problems, and an object thereof is to provide a defect detection how that can reliably detect minute defects master information carrier causes.

[0027]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention magnetically transfers an information signal for tracking servo or the like onto a magnetic recording medium to be incorporated in a product such as a magnetic recording / reproducing apparatus. In particular, it relates to a defect inspection method for a master information carrier used. The master information carrier has a magnetic film pattern corresponding to an information signal to be magnetically transferred to a magnetic recording medium.

The present invention concerning a method of inspecting a defect of a master information carrier is not a direct inspection of the master information carrier of interest when inspecting a defect which may exist in the master information carrier. A major feature is that an inspection substrate corresponding to a recording medium is prepared, and a defect that may exist on the master information carrier is transferred to the inspection substrate. It is an indirect defect inspection.

The reason for using the indirect defect inspection method instead of the direct defect inspection is that, as described above, a magnetic film pattern corresponding to an information signal for tracking servo is formed on the master information carrier. This is because, if the defect inspection is performed directly on the master information carrier, it is difficult to distinguish between the magnetic film pattern and defects such as abnormal protrusions and foreign substances, and it is difficult to secure the required defect inspection accuracy.

Therefore, by transferring the defects that may exist on the master information carrier to the inspection substrate, and by checking the defects that may have been transferred on the inspection substrate, the defects on the master information carrier can be checked. They are trying to find out what the defect is.

However, the point is that the defects that may exist on the master information carrier are simply transferred to the inspection substrate,
It is not a simple matter that the defect inspection should be performed on the inspection substrate. This is because if the inspection substrate originally has a defect, the defect on the inspection substrate may be mistaken for a defect on the master information carrier. Such inconvenience must be avoided. The present invention was created in consideration of that matter.

At least the following four items are considered as requirements for avoiding erroneously recognizing a defect on the inspection substrate as a defect on the master information carrier. The inspection substrate at the previous stage of transferring a defect that may exist on the master information carrier is referred to as a “first state inspection substrate”, and the inspection substrate on which the defect transfer process on the master information carrier is performed. Will be referred to as a “second state inspection substrate”.

(1) Prior to transferring the defects on the master information carrier to the inspection substrate, the defects that may originally exist on the inspection substrate in the first state are inspected first.

(2) Then, the master information carrier is brought into close contact with the inspection substrate in the first state after the defect inspection, so that the defect on the master information carrier is transferred to the inspection substrate after the defect inspection. To do. This is the inspection substrate in the second state.

(3) The defect-transferred inspection substrate in the second state, which is separated from the master information carrier, is inspected for defects on the inspection substrate in the second state.

(4) The defect inspection result for the inspection substrate in the second state is compared with the defect inspection result for the inspection substrate in the first state.

Defects which are not present in the inspection substrate in the first state but are present in the inspection substrate in the second state are defects transferred from the master information carrier to the inspection substrate, that is, the original defects. It is highly probable that the defect existed in the information carrier.

According to the present invention, by constructing such a peculiar and exquisite method, since a magnetic film pattern corresponding to an information signal for tracking servo or the like is formed in the first place, defects such as abnormal protrusions and foreign matter are formed. In the defect inspection of the master information carrier whose identification is difficult, the indirect defect inspection is not performed as described above, and the problems newly derived from the indirect defect inspection are overcome. Defect inspection can be performed with high accuracy on a master information carrier in a fatal situation where defect identification is originally difficult due to the existence of a pattern.

Various ideas as described below are developed in the novel idea according to the present invention.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

A master information carrier defect inspection method according to the first aspect of the present invention is a master information carrier defect inspection method having a magnetic film pattern corresponding to an information signal to be magnetically transferred to a magnetic recording medium. With respect to the inspection substrate in the first state to which the defect on the information carrier is to be transferred, a step of inspecting a defect that may originally exist on the inspection substrate in the first state; A step of bringing the master information carrier into close contact with the inspection substrate in a state, and transferring defects that may be present on the master information carrier to the inspection substrate that has been subjected to the defect inspection; A step of inspecting a defect on the inspection substrate in the second state for the inspection substrate in the second state corresponding to the defect transfer separated from the defect inspection result for the inspection substrate in the second state; It is characterized in that it comprises a step of determining a defect that may be present in the master information on a carrier by comparing the defect inspection result of the inspection for the substrate of the serial first state.

The operation of the first aspect of the invention is substantially the same as that described in the section [Means for solving the problems] above. In other words, the master information carrier, which is destined to have difficulty in identifying defects such as abnormal protrusions and foreign particles due to the formation of magnetic film patterns corresponding to information signals, is transferred to the inspection substrate and then inspected. Since it is not an indirect defect inspection and the problems newly derived from the indirect defect inspection are overcome, it is possible to improve the defect accuracy of the defect on the master information carrier.

The defect inspecting method of the master information carrier according to the second invention of the present application is, in the first invention, the step of inspecting the defect of the inspection substrate in the first state before the step of adhering, During the contact step, it is inspected whether or not the number of defects or the size of the defects in the defect inspection of the inspection substrate in the first state is equal to or less than a predetermined value. It is characterized in that a step is added to the step of interrupting and advancing to the step of adhering when the value is below a predetermined value.

The operation of the second invention is as follows. Although the defect inspection on the master information carrier is an indirect defect inspection after transferring to the inspection substrate, it is necessary to pay close attention when adopting such a completely new method. If the inspection substrate that is the target of transferring the defects on the master information carrier has a certain number of defects or more, since the defect transfer is performed in close contact, a certain number or more defects on the inspection substrate are newly added to the master information carrier of the liver and kidney. There is a risk of adverse effects such as defects in the. If that happens, it will be a fall. Therefore, if a defect is found in the defect inspection of the inspection substrate in the first state before adhesion, it is inspected whether the number of defects, the size of defects, or both of them are below a predetermined value. To When it exceeds the predetermined value, the defect inspection process is performed again by interrupting the process in order to avoid the above-mentioned adverse effects, exchanging it with another inspection substrate, or cleaning the same inspection substrate. If it is less than the predetermined value, it is determined that there is no adverse effect and the process proceeds to the adhesion step. This makes it possible to implement a good defect inspection on the master information carrier while avoiding the adverse effects caused by using the inspection substrate.

In the defect inspection method of the master information carrier of the third invention of the present application, in the first and second inventions, the step of the defect inspection for the inspection substrate in the first state is the one for the defect inspection means. The step of defect inspection for the inspection substrate in the second state includes the operation of measuring the rotation phase of the inspection substrate in the one state, and the rotation phase of the inspection substrate in the second state for the defect inspection means is measured. Including the work, the process of determining a defect on the master information carrier through the comparison includes
It is characterized in that the operation of correcting the deviation of the two rotational phases is included before the operation of the comparison.

The operation of the third invention is as follows. That is, the inspection substrate is mounted on the defect inspection means and subjected to the defect inspection in the first state, taken out from the defect inspection means and transferred to the adhesion means, and is subjected to the defect transfer of the master information carrier by the adhesion, and further adhered. It is removed from the means and transferred to the defect inspection means again, and undergoes the defect inspection in the second state. The defect inspection means for the defect inspection in the first state and the defect inspection means for the defect inspection in the second state may be the same or different, but the rotational phase of the inspection substrate in the first state and the second The rotation phase of the inspection board in the state does not always match exactly. Rather, it is expected that the probability of deviation will be higher. Therefore, prior to the comparison between the defect inspection result for the inspection substrate in the first state and the defect inspection result for the inspection substrate in the second state, the rotational phase correction for matching the two rotational phases is performed. . This rotation phase correction is generally performed on the defect inspection result (data). According to the present invention, it is possible to avoid the deterioration of the accuracy of the defect inspection result due to the rotational phase shift and to improve the defect inspection accuracy.

In the defect inspection method for a master information carrier according to a fourth invention of the present application, in the third invention, in the correction of the rotation phase, a correction from the inspection substrate when the inspection substrate is irradiated with light is performed. It is characterized in that the rotational phase of the defect detected based on the detection of the reflected light is corrected.

The operation of the fourth invention is as follows. That is, the specularly reflected light is mainly from the depressed portion (hollow) in the inspection substrate. On the contrary,
The scattered light is mainly from foreign matters such as particles on the inspection substrate. The scattered light largely varies in scattering direction and received light intensity due to subtle variations in laser irradiation position and angle. Therefore, when the rotational phase of the inspection substrate is corrected, the correction is performed based on the rotational phase of the detected defect based on the detection of the specular reflection light whose directionality and intensity are more stable. This makes it possible to improve the defect inspection accuracy.

The defect inspection method for a master information carrier according to the fifth invention of the present application is, in the third invention, the scattering of light from the inspection substrate when the inspection substrate is irradiated with light in the correction of the rotational phase. It is characterized in that the rotational phase of the defect detected based on the detection of light is corrected.
This describes that the rotational phase correction may be performed mainly with scattered light. However, the accuracy of defect inspection tends to be inferior to that in the case of specular reflection light.

A defect inspection method for a master information carrier according to a sixth aspect of the present invention is the method for inspecting defects of a master information carrier according to the third aspect, wherein the inspection substrate is directly radiated with light in the correction of the rotation phase. It is characterized in that the rotational phase of the defect detected based on the detection of the reflected light or the scattered light is corrected, and the rotational phase correction of the defect of the detection of the specular reflection light is prioritized. The operation in this case should be easily understood from the above items even if the description thereof is omitted.

It should be noted that, in the above, it is only stated that the regular reflection light or the scattered light is used in the rotational phase correction, and the use of the regular reflection light or the scattered light in the defect inspection is limited. Do not understand that The defect inspection need not be limited to the optical type. An electron microscope method or any other known method may be used.

In the defect inspection method of the master information carrier of the seventh invention of the present application, in the above first to sixth inventions, the defect inspection step for the inspection substrate in the first state is the first
The number of defects on the inspection substrate in the second state is counted, and the step of the defect inspection on the inspection substrate in the second state counts the number of defects on the inspection substrate in the second state. In the step of determining the defect on the master information carrier through the comparison, it is determined whether the defect count number for the inspection substrate in the first state and the defect count number for the inspection substrate in the second state are the same. If they are the same, it is determined that there is no defect in the master information carrier, and if they are different, it is determined that there is a defect.

The operation according to the seventh invention is as follows. When the number M of defects on the inspection substrate in the first state and the number N of defects on the inspection substrate in the second state are the same M = N, it is determined that the master information carrier has no defect, M ≠
When N is different, it is determined that the master information carrier has a defect. Such a determination method is a relatively simple method and has a high determination processing speed. Note that M and N are 0
In some cases.

The defect inspecting method of the master information carrier according to the eighth invention of the present application is the above first to sixth inventions, wherein the defect inspecting step for the inspection substrate in the first state is the first inspecting method.
The position information of the defect on the inspection substrate in the second state is extracted, and the step of the defect inspection for the inspection substrate in the second state extracts the position information of the defect on the inspection substrate in the second state. In the step of determining the defect on the master information carrier through the comparison, the defect position information regarding the inspection substrate in the first state and the defect position information regarding the inspection substrate in the second state are used. It is determined that the master information carrier has no defect when they are the same, and that there is a defect when they are different.

The operation of the eighth invention is as follows. When the defect position information on the inspection board in the first state and the defect position information on the inspection board in the second state are the same, it is determined that the master information carrier has no defect. Although it is determined that there is a defect, such a determination method is based on the defect position information, and therefore, it is determined that the master information carrier has a defect. Therefore, it is advantageous to obtain detailed data of what kind of defect is located at what coordinate. That is, it becomes easy to determine whether the defect is an abnormal protrusion, a foreign substance, or what kind of distribution. This is an effective technique for cleaning and reusing the inspection substrate.

In the defect inspection method for a master information carrier according to the ninth invention of the present application, in the eighth invention, the position information of the defect includes a plurality of minute unit areas in which the entire area of the inspection substrate is divided into a large number. When defects are continuously discriminated over a region, the plurality of continuous unit regions are regarded as one region, and the barycenter of the regarded region or its vicinity is used as position information of one defect.

The operation of the ninth invention is as follows. That is, it is empirically known that, when a plurality of unit areas that are determined to have a defect are continuous, it is highly possible that the unit areas separately discriminate different portions of a single defect. By considering a linear defect that is longer than a certain amount and a defect that has a large spread that is greater than a certain amount as one,
It is possible to improve the accuracy of defect inspection.

In the defect inspection method for a master information carrier according to the tenth invention of the present application, in the above-mentioned first to ninth inventions, the positional deviation in the surface direction at the time of the close contact with the master information carrier is taken into consideration as the inspection substrate. Then, the one having a size equal to or larger than the maximum area of the positional deviation in the surface direction is used.

The operation of the tenth invention is as follows. First, the background will be described. When the magnetic recording medium and the master information carrier are brought into close contact with each other (Note: here, the object of close contact with the master information carrier is not the inspection substrate but the magnetic recording medium.) The positional relationship between the two is always the same. Is ideal. However, in reality, it is slightly different. This is the displacement in the surface direction. The amount of deviation is
Although it is on the order of several μm to several hundreds of μm, a region wider than the outer shape of the magnetic recording medium by the above-described amount of displacement is the maximum region of positional displacement in the surface direction. Even if there is no defect in the area corresponding to the magnetic recording medium in the master information carrier, there may be a defect in an extremely thin annular area (extremely annular area) between the maximum surface misalignment area and the outer shape of the magnetic recording medium. .

When the master information carrier is displaced in the surface direction with respect to the magnetic recording medium in the case where there is a defect, especially foreign matter, in the ultrafine annular area of the master information carrier, the foreign matter in the ultrafine annular area hits the surface of the magnetic recording medium. In contact with each other, it hinders uniform adhesion of the entire surface of the master information carrier and the magnetic recording medium. Then, the accuracy of magnetically transferring the information signal of the master information carrier to the magnetic recording medium may be reduced. Therefore, when inspecting the master information carrier that is brought into close contact with the magnetic recording medium for defects, it is necessary to include the ultra-fine annular region in consideration of the positional deviation in the surface direction.

If the inspection substrate has the same size as the magnetic recording medium, and the master information carrier and the inspection substrate are accurately and concentrically adhered to each other without any positional deviation in the surface direction during contact (Note : Here, the object to which the master information carrier adheres is the inspection substrate.) If there is a foreign substance in the ultrafine annular region of the master information carrier, the presence of the foreign substance may be overlooked. If the master information carrier in this case is used as a normal master information carrier for magnetic transfer of information signals, it will contribute to the above-mentioned decrease in magnetic transfer accuracy.

The tenth invention and the eleventh invention of the present application are proposed for the defect inspection including the ultrafine annular area in the master information carrier.

It is conceivable to use an inspection substrate of the same size as the other party's magnetic recording medium to which the information signal of the magnetic film pattern is to be magnetically transferred from the master information carrier. That is the eleventh invention described below. A tenth aspect of the present invention is to use an inspection substrate having a size larger than that of the magnetic recording medium.

The maximum area of the positional deviation in the surface direction is a combination of the area within the outer shape of the magnetic recording medium and the ultrafine annular area. A tenth aspect of the present invention is to use a substrate having a size equal to or larger than the maximum area of the positional deviation in the surface direction as the inspection substrate. This relatively large size test substrate itself covers the micro annular region. When the master information carrier and the inspection substrate are brought into close contact with each other, the maximum area of the plane information positional displacement in the master information carrier can be brought into close contact with the inspection substrate without fail, no matter how they are displaced in the surface direction. . That is, if there is a foreign substance in the ultra-fine annular region, the presence of the foreign substance is surely transferred to the inspection substrate. That is, it is possible to avoid overlooking the presence of foreign matter in the ultrafine annular region and improve the defect inspection accuracy of the master information carrier.

Further, in the case of the eleventh invention described later, the master information carrier and the inspection substrate are brought into contact with each other a plurality of times by changing the contact position, but in the case of the tenth invention, this is the case. There is no need for repeated close contact with various close contact positions,
Since it is possible to complete the process only once, the inspection efficiency is good.

In the defect inspection method for a master information carrier of the eleventh invention of the present application, in the first to ninth inventions, the inspection substrate having substantially the same size as the magnetic recording medium is used. In the close contact between the master information carrier and the inspection substrate, in consideration of the positional deviation in the surface direction when the master information carrier is in close contact, with respect to the entire maximum area in the master information carrier of the positional deviation in the surface direction. It is characterized in that the contact position of the master information carrier and the inspection substrate is changed so that the inspection information substrate and the inspection substrate having substantially the same size as the magnetic recording medium are in contact with each other a plurality of times.

The operation of the eleventh invention is as follows. That is, by changing the contact position and contacting the master information carrier and the inspection substrate a plurality of times, the entire maximum area of the positional deviation of the master information carrier including the ultra-fine annular region is adhered to the inspection substrate. Therefore, if there is a foreign substance in the ultrafine annular region, the presence of the foreign substance can be reliably transferred to the inspection substrate. That is, it is possible to avoid overlooking the presence of foreign matter in the ultrafine annular region and improve the defect inspection accuracy of the master information carrier.

In addition, the use of the same size as the counterpart magnetic recording medium to which the information signal of the magnetic film pattern is originally to be magnetically transferred from the master information carrier is used as the inspection substrate. It enables to convert a blank plate into an inspection substrate. Transferring the magnetic recording medium or the base plate of the magnetic recording medium to the inspection substrate means that a special inspection substrate does not have to be specially manufactured, which simplifies the defect inspection facility and reduces the cost. It becomes possible to change.

Further extension of the twelfth invention suggests that the size of the inspection substrate may be smaller than that of the magnetic recording medium. It is possible to cover by repeated contact with changing the contact position. The present invention may include such conditions.

A twelfth invention of the present application is the method for inspecting defects of a master information carrier according to any one of the first to eleventh inventions, wherein the inspection substrate is made of a material whose main component is a constituent main component of the magnetic recording medium. It is characterized by using the existing one. This is a concept in which at least a part of the magnetic recording medium or the manufacturing state of the magnetic recording medium is diverted to the inspection substrate, and the cost can be reduced.

In the defect inspection method for a master information carrier of the thirteenth invention of the present application, in the above-mentioned first to twelfth inventions, as the inspection substrate, one whose hardness is lower than that of the master information carrier is used. Is characterized by.

The operation of the thirteenth invention is as follows. That is, conversely, when using the inspection substrate having the same hardness as or higher than the hardness of the master information carrier, the inspection substrate is unlikely to be dented due to foreign matter or abnormal protrusions on the master information carrier. Become. By using the inspection substrate having a hardness lower than the hardness of the master information carrier as in the present invention, it is possible to surely cause the inspection substrate to have a dent caused by a foreign substance or an abnormal protrusion on the master information carrier. It is possible to ensure the detection of foreign matter and abnormal protrusions on the master information carrier.

In the defect inspection method for a master information carrier according to the fourteenth invention of the present application, in the first through thirteenth inventions, the lubricant applied on the magnetic recording medium as the inspection substrate is omitted. The feature is to use the one.

The operation of the fourteenth invention is as follows. That is, on the contrary, when a test substrate coated with a lubricant is used, foreign matter on the master information carrier is less likely to be adsorbed on the test substrate. By using the inspection substrate without the lubricant as in the present invention, it becomes possible to enhance the adsorption of foreign matter on the master information carrier and ensure the detection of foreign matter on the master information carrier with the inspection substrate. .

The master information carrier defect inspection method of the fifteenth invention of the present application is characterized in that, in the above-mentioned first to fourteenth inventions, the inspection substrate has a magnetized contact side surface. There is.

The operation of the fifteenth invention is as follows. That is, when there is an abnormal protrusion in the magnetic film pattern of the master information carrier, the magnetic film may be peeled off from the master information carrier due to the contact / separation operation, but it is said that the surface of the inspection substrate has magnetic characteristics. The peeled magnetic layer can be surely magnetically attracted to the inspection substrate side, and the surface of the master information carrier is prevented from being contaminated with the peeled magnetic film.

The sixteenth invention of the present application relates to a magnetic film pattern magnetic transfer method using a master information carrier, wherein the defect inspection is performed by the master information carrier defect inspection method of the first to fifteenth inventions, and it is determined as a non-defective product. A method of magnetically transferring an information signal by the magnetic film pattern in the master information carrier to a magnetic recording medium by using the master information carrier, wherein the surface of the master information carrier on the side where the magnetic film pattern is formed is It is characterized in that the information signal by the magnetic film pattern of the master information carrier is magnetically transferred to the magnetic recording medium by bringing it into close contact with the magnetic recording medium and applying an external magnetic field.

The seventeenth invention of the present application also relates to the magnetic film pattern magnetic transfer method using the master information carrier, and the defect inspection is performed by the master information carrier defect inspection method of the first to fifteenth inventions, and it is determined as a non-defective product. A method of magnetically transferring an information signal by the magnetic film pattern in the master information carrier to the magnetic recording medium by using the master information carrier, wherein the magnetic film pattern of the master information carrier is magnetized in advance, Magnetically transferring an information signal based on the magnetic film pattern of the master information carrier to the magnetic recording medium by bringing the surface of the master information carrier on the side where the magnetized magnetic film pattern is formed into close contact with the magnetic recording medium. Is characterized by.

The difference between the sixteenth invention and the seventeenth invention is that
The difference is whether an external magnetic field is applied or, instead, it is magnetized beforehand. In these inventions, since the information signal based on the magnetic film pattern is magnetically transferred to the magnetic recording medium by using the master information carrier that has been properly inspected for defects, the magnetic transfer of the information signal can be realized efficiently and accurately. It will be possible.

[0080] The first 16-second 17 master information carrier utilization of the magnetic film patterns a magnetic transfer method magnetic recording medium in which the information signal is magnetically transferred by the shape of the disk de I <br/> disk-shaped magnetic recording medium of the invention And a magnetic recording / reproducing apparatus including a magnetic head for recording / reproducing on / from the disk-shaped magnetic recording medium, an information signal in a magnetic film pattern of a master information carrier is magnetically transferred with high accuracy. since the disc-shaped magnetic recording medium which are mounted, ing to those excellent performance of control such as tracking servo.

(Specific Embodiment) A specific embodiment of a defect inspection method for a master information carrier according to the present invention will be described below with reference to the drawings.

(Embodiment 1) The contents of magnetic transfer in Embodiment 1 of the present invention will be described with reference to FIGS.

FIG. 1 is a sectional view of the magnetic transfer apparatus according to the present embodiment, showing a state in which a master information carrier 2 for magnetic transfer and a magnetic disk 1 as a magnetic recording medium are separated from each other. FIG. 2 shows a master information carrier 2 and a magnetic disk 1.
Shows the state when is in close contact. FIG. 3 is a view showing the contact surface 3 of the master information carrier 2 with the magnetic disk 1, and the grooves 4 extend radially from the center of the master information carrier 2. In the present embodiment, the groove depth is set to about 5 μm.

In FIG. 1, 1 is a magnetic disk, and 2 is a magnetic transfer master for magnetic transfer. Reference numeral 3 denotes a contact surface of the master information carrier 2 with the magnetic disk 1, and the contact surface 3 is provided with a groove 4 radially extending from the center of the master information carrier 2. Reference numeral 5 denotes a boss fixed to the central portion of the master information carrier 2, 6 denotes a support base for supporting the magnetic disk 1, and a ventilation hole 7 for flowing gas is provided in the central portion. Reference numeral 8 is a passage for discharging gas between the master information carrier 2 and the magnetic disk 1 and for sending gas under pressure to the groove 4 which is a space between them, and 9 is a gas discharge port for discharging gas from the passage 8. Reference numeral 10 is a suction pump connected to the gas discharge port 9, and 11 is an exhaust valve for controlling the discharge of gas. Also,
12 is an air supply pump for pumping gas to the passage 8, 13
Is an air supply valve for controlling air supply.

Here, the air supply pump 12 has 0.01 μm.
m air filter is provided (not shown),
It is configured so that foreign matter of 0.01 μm or more does not enter the passage 8. Reference numeral 14 is a holding arm for holding the master information carrier 2, which is fixed to the master information carrier 2.

As a fixing method, there is a method such as adhesion, but as shown in FIG. 1, the master information carrier 2 may be adsorbed by sucking gas from a through hole provided in the holding arm 14.

The holding arm 14 is further positioned by a guide member 16 so as to be vertically slidable via an upper boss portion.

However, the method of positioning the master information carrier 2 is not limited to the method of using the holding arm 14, and it can be performed by fitting the outer circumference of the boss 5 to the inner circumference hole of the magnetic disk 1, for example. . In such a case, the shape of the boss 5 is configured as shown in FIG. 4, and the gas between the master information carrier 2 and the magnetic disk 1 is discharged and pumped through the notch 51 provided on the outer peripheral portion of the boss 5. To be done.

Next, the steps of suction / pressure feeding will be described in detail with reference to FIGS.

First, the step of separating by pressure feeding will be described with reference to FIG. Exhaust valve 11 is closed and air supply valve 13
The gas is caused to flow into the passage 8 by operating the air supply pump 12 in a state in which is opened. Then, as shown by the arrow A in FIG. 1, air is pumped upward in the vent hole 7. As a result, the air pressure-fed to the ventilation hole 7 pushes the boss 5 upward, and as shown by the arrow B,
Air is pumped into the groove 4. The air pressure-fed to the groove 4 spreads radially from the center of the master information carrier 2 to the outer periphery through the groove 4. Then, it further escapes from the groove 4 to the atmosphere through the gap between the master information carrier 2 and the magnetic disk 1.

The time elapsed at this time and the master information carrier 2
FIG. 5 shows the relationship between the atmospheric pressure of the space sandwiched between the magnetic disk 1 and the magnetic disk 1 (hereinafter referred to as space S). In FIG. 5, the air pressure in the space S is 101.3 kp after the passage of time of 3 seconds.
Momentary rise from a, then 130 kp for about 1 second
The period in which the atmospheric pressure of about a is maintained corresponds to the state in which the master information carrier 2 and the magnetic disk 1 described above are separated from each other.

In this embodiment, the upper surface of the holding arm 14 is guided by the guide member when the master information carrier 2 rises 0.5 mm integrally with the holding arm 14 from the state where the magnetic disk 1 and the master information carrier 2 are in close contact with each other. By making contact with the lower surface of 16, the distance between the magnetic disk 1 and the master information carrier 2 is controlled.

Next, the process of adhesion by suction will be described with reference to FIG.
Will be explained.

The air supply pump 12 is stopped and the air supply valve 13 is closed. Then, the holding arm 14 to which the magnetic disk 1 is fixed moves downward due to its own weight, and the boss 5 moves the magnetic disk 1 to the boss 5.
Is mounted on the magnetic disk 1 in a state of being fitted with the inner peripheral hole of the magnetic disk 1. Then, the exhaust valve 11 is opened and the suction pump 10 is operated. Then, as shown by the arrow C in FIG.
Since the gas is discharged downward, the gas inside the groove 4, that is, the gas in the space S is also discharged through the gap between the inner peripheral hole of the magnetic disk 1 and the boss 5.

Here, as shown in FIG. 3, the groove 4 does not have a shape that extends to the outermost periphery of the master information carrier 2, so that the master information carrier 2 and the magnetic disk 1 are completely formed in the outermost donut-shaped portion. It is in a state of being in close contact with the circumference, the space S is in a sealed state, and its pressure is lower than atmospheric pressure. Therefore, the magnetic disk 1 is pressed against the master information carrier 2 by the atmospheric pressure 15.

In FIG. 5, the section in which the atmospheric pressure of the space S is about 30 kpa corresponds to the above-mentioned close contact state.

Next, as shown in FIG. 2, the magnet 17 is moved in the direction of arrow D to approach the master information carrier 2,
When the distance becomes about 1 mm, the movement in the direction of arrow D is stopped, and then the magnet 17 is rotated one or more revolutions in the circumferential direction of the magnetic disk 1, that is, around the guide member 16 in the direction of arrow E. By doing so, a magnetic field (external magnetic field) necessary for transfer is applied.

As described above, in magnetic transfer, the operation of the magnetic disk 1 is only close contact / pneumatic pressure, so that the rotational phase of the magnetic disk 1 does not greatly shift before and after magnetic transfer.

Here, FIG. 6 to FIG.
This will be described in detail with reference to FIG.

As shown in FIG. 6 which schematically shows a plane of an example of the master information carrier 2, one main surface of the master information carrier 2, that is, the surface of the magnetic disk 1 on the side in contact with the ferromagnetic thin film surface, is substantially formed. The signal regions 2a are radially formed. Figure 3
6 and FIG. 6 are schematic diagrams, and in reality, FIG.
The signal area 2a in FIG. 3 is formed on the contact surface in FIG.

An enlarged view of a portion F surrounded by a dotted line in FIG. 6 is schematically shown in FIG. As shown in FIG. 7, a pattern of a digital information signal to be recorded on the magnetic recording medium is formed in the signal area 2a. For example, a master information pattern is formed at a position corresponding to preformat recording by a magnetic portion formed of a ferromagnetic thin film in a pattern shape corresponding to the digital information signal.

In FIG. 7, the hatched portion is the magnetic portion made of a ferromagnetic thin film. This Figure 7
The master information pattern shown in (1) is obtained by sequentially arranging areas of the clock signal, the tracking servo signal, the address information signal, etc. in the track length direction. The master information pattern shown in FIG. 7 is an example, and the configuration, arrangement, etc. of the master information pattern will be appropriately determined according to the digital information signal recorded on the magnetic recording medium.

For example, when a reference signal is first recorded on a magnetic film of a hard disk as in a hard disk drive and preformat recording such as a tracking servo signal is performed based on the reference signal, the master information carrier according to the present invention. Pre-format recording such as tracking servo signals is performed on the magnetic head of the hard disk drive by pre-recording only the reference signal used for pre-format recording on the magnetic film of the hard disk by using the May be used.

A partial cross section of the region shown in FIGS. 6 and 7 is shown in FIG.
Shown in.

As shown in FIG. 8, the master information carrier 2 is
A plurality of minute array patterns corresponding to information signals are formed on one main surface of the disk-shaped substrate 2b made of a non-magnetic material such as a Si substrate, a glass substrate, a plastic substrate, that is, the surface on the side where the surface of the magnetic disk 1 contacts. The recess 2c is formed in a shape, and the ferromagnetic thin film 2d, which is a magnetic part, is embedded in the recess 2c of the base 2b.

Here, as the ferromagnetic thin film 2d, many kinds of magnetic materials can be used regardless of hard magnetic material, semi-hard magnetic material, and soft magnetic material, and a digital information signal is transferred to a magnetic recording medium. Anything that can be recorded is acceptable. For example, Fe, Co, an Fe-Co alloy, or the like can be used.

In order to generate a sufficient recording magnetic field regardless of the type of magnetic recording medium on which master information is recorded, it is preferable that the saturation flux density of the magnetic material is large. In particular,
For a magnetic disk having a high coercive force exceeding 2000 Oersted and a flexible disk having a large magnetic layer thickness, sufficient recording may not be performed when the saturation magnetic flux density is 0.8 Tesla or less, and therefore, in general, it is generally impossible. Is
A magnetic material having a saturation magnetic flux density of 0.8 Tesla or more, preferably 1.0 Tesla or more is used.

The thickness of the ferromagnetic thin film 2d depends on the bit length, the saturation magnetization of the magnetic recording medium and the film thickness of the magnetic layer. For example, the bit length is about 1 μm, and the saturation magnetization of the magnetic recording medium is about 50.
0 emu / cc, the thickness of the magnetic layer of the magnetic recording medium is about 20
In the case of nm, it may be about 50 nm to 500 nm.

Here, in such a recording method, in order to obtain good recording signal quality, the pre-recording is performed based on the arrangement pattern of the soft magnetic thin film or the semi-hard magnetic thin film as the ferromagnetic thin film provided on the master information carrier. During format recording, it is desirable to excite it and magnetize it uniformly.
Further, it is desirable that the magnetic recording medium such as a hard disk is uniformly DC-erased before the signal recording using the master information carrier.

Next, a method of manufacturing the master information carrier 2 will be described.

That is, for the master information carrier used in the recording method of the present invention, a resist film is formed on the surface of a Si substrate, and the resist film is formed by a lithography technique such as a photolithography method using a laser beam or an electron beam. After exposure, development, and patterning, etching is performed by dry etching or the like to form a fine concavo-convex shape corresponding to an information signal, and then a ferromagnetic thin film made of Co or the like is sputtered, vacuum deposited, or ion plated. Method, CVD method, plating method, etc., it is possible to obtain a master information carrier in which a ferromagnetic thin film is embedded in a recess and which has a magnetic portion corresponding to an information signal.

The method of forming the uneven shape on the surface of the master information carrier is not limited to the above-mentioned method.
For example, a fine concavo-convex shape may be directly formed by using a laser beam, an electron beam or an ion beam, or a fine concavo-convex shape may be directly formed by machining.

Next, the procedure for transferring and recording the information signal corresponding to the pattern shape formed on the master information carrier 2 on the magnetic disk will be described in more detail with reference to FIGS. 9 to 11.

First, in the state where the magnet is brought close to the magnetic disk 1, the magnet is rotated parallel to the magnetic disk 1 with the central axis of the magnetic disk 1 as the rotation axis, so that the magnetic disk 1 as shown by the arrow in FIG. Is magnetized in one direction in advance (initialization).

Next, as described above, with the master information carrier 2 positioned and superposed on the magnetic disk 1,
The master information carrier 2 and the magnetic disk 1 are brought into close contact with each other uniformly, and then a magnetic field is applied in the direction opposite to the initialization as shown by an arrow E in FIG. The magnetic thin film 2d is magnetized, and the predetermined area 1 of the magnetic disk 1 superposed on the master information carrier 2
In b, an information signal corresponding to the pattern shape of the magnetic portion 2d is recorded as shown in FIG. The arrow shown in FIG. 10 indicates the direction of the magnetic field of the magnetization pattern transferred and recorded on the magnetic disk 1 at this time.

FIG. 11 shows a state during the magnetization process. As shown in FIG. 11, a magnetic field is applied to the master information carrier 2 from the outside while the master information carrier 2 is in close contact with the magnetic disk 1. By magnetizing the magnetic portion 2d by
Information signals can be recorded on the ferromagnetic layer 1c of the magnetic disk 1. That is, by using the master information carrier 2 formed by forming the magnetic portion 2d made of a ferromagnetic thin film in the array pattern shape corresponding to a predetermined information signal on the non-magnetic substrate 2b, the magnetization pattern corresponding to the information signal is used. Can be magnetically transferred and recorded on the magnetic disk 1.

As a method for transferring and recording the pattern of the master information carrier 2 on the magnetic disk 1, other than the method of applying an external magnetic field with the master information carrier 2 in contact with the magnetic disk 1 as described above. There is also a method in which the magnetic portion 2d of the master information carrier 2 is magnetized in advance and the master information carrier 2 is brought into close contact with the magnetic disk 1 in that state. Even with this method, the information signal is transferred and recorded. be able to.

Then, the separating means shown in FIG. 1 is implemented again. That is, the exhaust valve 11 is closed, the air supply valve 13 is opened, and the air supply pump 12 is operated. Then, arrows A and B
As shown in FIG. 3, the gas is pumped, the master information carrier 2 moves integrally with the holding arm 14 by the force of the gas pumping, and stops when the upper surface of the holding arm 14 contacts the guide member 16. At this time, as shown by the arrow B, the gas is kept in a state of being radially pumped from the center of the master information carrier 2 to the outer peripheral side through the groove 4.

Here, if an abnormal protrusion or a foreign substance is present on the contact surface 3 of the master information carrier 2, the magnetic transfer will cause a defect in the magnetic disk 1.

Next, a defect inspection method for a master information carrier and a magnetic recording / reproducing apparatus according to an embodiment of the present invention will be described with reference to FIGS.

FIG. 12 is a flow chart showing a method of inspecting a defect of the master information carrier in this embodiment.

First, the step of inspecting defects on the surface of the magnetic disk, which is the step of ST1 and ST4 of FIG. 12, will be described. The steps ST1 and ST4 are performed by using a defect inspection device which is a well-known means. Optical irradiation is performed by irradiating the surface of the disk with a laser and detecting the shape and size of each defect differently. A property is used, that is, a method of detecting a defect by receiving specular reflection light or scattered light of laser light is used. The outline of the defect inspection apparatus used in this embodiment will be briefly described below.

FIG. 13 is a diagram showing the defect inspection apparatus used in the steps ST1 and ST4 of FIG.
In FIG. 13, reference numeral 100 is an inspection substrate in which a NiP plating layer of about 10 μm is formed on the surface of an aluminum alloy substrate to prevent deformation, 101 is a laser light transmission system, and 102
Is a specular reflection light receiving system, 103 is a scattered light receiving system, and 104 is a data processing device. For inspection by using a rotary motor and a linear drive unit (not shown) for placing the inspection substrate 100 on the inspection substrate 100 by projecting the laser light so that a laser spot is formed on the surface of the inspection substrate 100. Board 100
The surface is spirally scanned with a laser spot. When there is a defect on the surface of the inspection substrate 100, the laser spot is scattered, so the scattered light is received by the scattered light receiving system 103 to obtain a defect data signal. The regular reflection light is received by the regular reflection light receiving system 102. In this way, each light receiving system is provided so as to correspond to the specular reflection light and the scattered light having different light intensities depending on the type of defect. Further, optical elements such as filters and lenses are provided in order to efficiently receive desired light (that is, specularly reflected light and scattered light). The light received by each light receiving system is converted into defect data via a predetermined circuit, and the data processing device 104
Entered in.

The defect data signal obtained by receiving light by each light receiving system is a predetermined unit cell on the disk surface (in this embodiment, a minute distance Δ in the radial direction of the disk).
It is stored in the address of the memory corresponding to a unit area which is a minute rectangular cell formed by r and a minute distance Δθ in the circumferential direction. The unit area of the defect inspection apparatus used in this embodiment is Δr = 10 μm and Δθ = 0.125 °.

However, as it is, even if a defect having a predetermined length or width such as one dent, scratch or particle is one defect, when it exists over a plurality of continuous unit areas, Instead of being recognized as one defect, many defects are recognized. Therefore, if there is defective data in any of a predetermined number of addresses adjacent to the address storing the defective data, the continuity of each address is identified as being continuous, and the addresses determined to be continuous by this identification. Is evaluated as one defect. As a result, the number of groups of various defects is shown regardless of the size and shape. The position coordinates of a defect are defined as the center of gravity of a group of addresses that are considered to be continuous.

In the defect inspection apparatus used in the present embodiment, the surface of the inspection substrate 100 is inspected at the time of inspection so that the rotational phase of the inspection substrate 100 does not greatly shift when the inspection substrate 100 is put in and taken out. A rotary motor (not shown) for spirally scanning is rotated back to the origin before and after the defect inspection.

In step ST1, the inspection substrate 100 in the first state is inspected for any defects that may originally exist in the inspection substrate 100 in the first state.

Next, in step ST2, it is confirmed whether or not foreign matter is present on the surface of the inspection substrate 100 in the first state. As a confirmation method, an optical defect inspection method which is a known means is used to inspect the foreign matter on the surface of the inspection substrate 100 in the first state. In this embodiment, an optical inspection apparatus which is different from the defect inspection apparatus of ST1 and which is equivalent to ST1 is used to set the detection slice level of the foreign matter to 1 μm and
It was inspected whether or not foreign matter of m or more was attached on the surface of the inspection substrate. After the inspection, if there is a foreign matter of 1 μm or more, it is determined to be NG (defective product), and if it is not present, it is determined to be OK (good product). In the case of OK, the following step ST3 is performed. In the case of NG, the inspection substrate is cleaned and regenerated. If the reproduction is also defective, discard it.

As described above, the first step is performed before the adhesion step of ST3.
By inspecting the foreign matter on the surface of the inspection substrate 100 in the state, the foreign matter on the surface of the inspection substrate 100 in the first state may conversely adhere to the master information carrier 2 and damage the master information carrier 2. It becomes possible to prevent it.

Further, in the step ST2 as well as in the step ST1, the inspection substrate 100 in the first state is prevented from being largely deviated in the rotational phase when the inspection substrate 100 in the first state is put in and taken out. At the same time, a rotary motor (not shown) that scans the surface of the inspection substrate 100 in the first state spirally returns the origin to the rotational phase before and after the defect inspection.

The step ST3 is a step of bringing the master information carrier 2 and the inspection substrate 100 in the first state in which the defect inspection has been completed into close contact with each other, and is the same as the contents described with reference to FIGS. That is, the magnetic disk 1 in FIGS. 1 and 2 may be replaced with the inspection substrate 100 in the first state, and the other configurations are exactly the same.

After that, the defects on the surface of the inspection substrate 100 in the second state are inspected. That is, the process of ST4 is performed.
The step ST4 is a step for inspecting whether or not a defect has occurred in the inspection substrate 100 by bringing the master information carrier 2 into close contact with the inspection substrate 100 in the first state. The inspection substrate in which the defects on the master information carrier 2 are transferred by the contact is the inspection substrate in the second state.

FIG. 14 is a result of the defect inspection of the inspection substrate 100 in the first state performed in the step ST1, and FIG. 15 is a result of the defect inspection performed in the step ST4, that is, the inspection substrate 100 in the second state after the adhesion. The defect inspection results are shown respectively.
14 and 15, a black circle (●) indicates the center of gravity of a defect received by the light receiving element of the regular reflection light receiving system 102.
The (center) position and the triangle mark (Δ) indicate the center of gravity (center) position of the result of light reception by the light receiving element of the scattered light receiving system 103.

Next, the step of ST5 of FIG. 12, which is a step of determining a defect caused by the master information carrier, will be described with reference to FIG. FIG. 16 is a flowchart showing the process of ST5. In FIG. 16, ST6 and ST7 are the defect inspection results of the step ST1 and the step ST4, respectively, and correspond to FIGS. 14 and 15 in the present embodiment, respectively. ST8 is the process of ST1 and S
This is a step of detecting the rotational phase shift of the inspection substrate in the defect inspection result of the step T4. First, as shown in ST9, regarding the defect inspection results on the surface of the inspection substrate 100 in the first state and the second state performed in the process of ST1 and the process of ST4, the rotation phase and position at the time of measurement of both are Specify the range that may shift. In the present embodiment, the rotary motor is provided with a return-to-origin function so that the rotational phase of the magnetic disk is not significantly deviated in the steps ST1, ST2, and ST4. Further, in the contact process of ST3, the inspection substrate 10 in the first state
Since 0 is not rotated, the rotation phase of the disk does not significantly shift. However, there is a possibility that the rotational phase may be slightly shifted due to variations in the process of transporting the inspection substrate 100 or when returning to the origin. It is preferable to specify the maximum value of the variation in the setting range of the rotational phase shift and the positional shift at this time. In the present embodiment, the range of the rotational phase shift is 1
The range of 0 ° and the positional deviation was set to 0.5 mm.

Next, step ST10 is carried out. That is, the defect inspection results of the process of ST1 and the process of ST4 are compared, and in the same defect type, the rotational phase shift amount is 10
Defects that are within ° and the amount of displacement is within 0.5 mm are listed. Among them, it is determined whether or not there is a defect detected by the light receiving element of the regular reflection light receiving system 102. If there is a defect detected by the light receiving element of the specular reflection light receiving system 102, as shown in ST11, the phase shift amount between the defects is the inspection substrate 100 in the first state in the step ST1.
And ST4, the amount of deviation from the inspection substrate 100 in the second state is determined. If there is no defect detected by the specular reflection light receiving element R, the detection result of scattered light is recognized as a phase shift. As described above, it is preferable to give priority to the result detected by the specular reflection light rather than the result detected by the scattered light of the defect used as the defect for the rotational phase correction. The reason for this will be described with reference to FIG.

FIG. 17 shows the defect measurement results of the inspection board defect inspection apparatus used in the steps ST1 and ST4. The same inspection board is returned to the origin for each measurement, and the rotary motor is turned on. It is the result which showed the gravity center (center) position of various defects when it measured 20 times continuously without removing. In FIG. 17, (a) and (b) are foreign matters, that is, defects detected by the light receiving element of the scattered light receiving system 103, and (c) and (d) are dents, that is, the regular reflection light receiving system 1.
Each of the defects detected by the light receiving element 02 is shown.
Further, the vertical direction in the drawing is the radial direction r of the inspection substrate 100,
The horizontal direction indicates the circumferential direction θ of the inspection substrate 100. The unit cell of the defect inspection apparatus used in this embodiment is Δr
= 10 μm and Δθ = 0.125 °. The number in each cell indicates the number of times the defect center was detected in that cell. As is clear from the measurement result of FIG.
(A) and (b), that is, variations in the defect position detected by the light receiving element of the scattered light receiving system 103 are the same as (c) and (d), that is, variations in the defect position detected by the light receiving element of the specular reflection light receiving system 102. By comparison, it can be seen that it is larger. Since the light receiving element of the scattered light receiving system 103 detects the scattered portion of the light from the laser spot, even if the same defect is detected, if the position or angle of laser irradiation is slightly deviated, the positional deviation of the detected portion This is because it is more likely to be the cause than the regular reflection. Therefore, it is preferable to give priority to the result detected by the specular reflection light receiving element over the result detected by the scattered light of the defect used as the defect for which the rotational phase correction is performed.

As is clear from the above, it is possible to perform a more accurate defect inspection by giving priority to the result of detecting the defect used for the defect for the rotational phase correction by the specular reflection light receiving element. Become.

By comparing the defect inspection results of the ST1 process and the ST4 process, the defects detected by the specular reflection light receiving element and having a rotational phase shift amount of 10 ° or less and a positional shift amount of 0.5 mm or less are determined. The enumerated results are shown in FIG.

In FIG. 18, ΔR is the difference in the radial direction between the defect inspection result of the step ST1 and the defect inspection result of the step ST4, and Δθ is the defect inspection result of the step ST1 and the defect inspection result of the step ST4. It represents the difference in the circumferential direction. FIG.
Therefore, in the defect inspection results in the steps ST1 and ST4, it can be determined that the rotational phase shift of the inspection substrate 100 during the defect inspection is 4.125 °. This is determined by majority vote. If the same data exists in multiple cases, the average value of them is adopted.

Next, the step of phase correction shown in ST13 of FIG. 16 is carried out. As shown in FIG. 18, the phase shift at the time of defect inspection measurement in the step ST1 and the step ST4 is 4.125 °. Based on this result, the defect inspection result data in the step ST1 is rotated by 4.125 ° in the direction in which the phase shift is corrected, that is, in the clockwise direction in FIG.

Next, the subtraction processing shown in ST14 of FIG. 16 is carried out. The subtraction process is the inspection substrate 1 in the second state.
00 for defect inspection and inspection substrate 1 in the first state
10 is a representative example of a comparison process with a defect inspection result for No. 00.

The defect inspection result of the step ST1 is subtracted from the defect inspection result of the step ST1 and the step ST4 in which the phase correction is performed by the step ST13. That is, [defect inspection result of step ST4]-[defect inspection result of step ST1].

When performing the subtraction, it is necessary to set the range in which the subtraction is performed by regarding it as the same defect. However, in the present embodiment, in consideration of the deviation of the positional deviation, the defects of the same type are radial direction. Defects in which the difference in r was 0.05 mm or less and the difference in the circumferential direction θ was 1 ° or less were regarded as the same defect and subtraction was performed. The result of the subtraction is shown in FIG.

FIG. 19 shows defect display data after the subtraction process which is the step of ST14 is performed by the above method.
From the results of FIG. 19, it can be seen that there are two defects detected by the light receiving element of the specular reflection light receiving system 102 and seven defects detected by the light receiving element of the scattered light receiving system 103.

As a result of observing the defective portion with a microscope, the defect detected by the light receiving element of the regular reflection light receiving system 102 is an abnormal protrusion existing on the surface of the master information carrier 2, and the defect by the light receiving element of the scattered light receiving system 103. It was confirmed that the detected defects were fine particles attached to the surface of the master information carrier 2.

Here, it is preferable that no lubricant is applied to the inspection substrate 100. This is because when a lubricant is applied like a normal magnetic disk, the adsorbability of foreign matter is reduced, so it becomes difficult for foreign matter to adhere to the inspection substrate 100 side, which leads to a reduction in the accuracy of defect inspection. In order to avoid a decrease in accuracy and to perform a more accurate defect inspection, the lubricant is not applied unlike a general magnetic recording medium.

As in this embodiment, by using the inspection substrate whose surface is the NiP plating layer without applying the lubricant, it is possible to surely inspect the foreign matter adhering to the master information carrier. It can be attached to the substrate.

As shown in this embodiment, the hardness of the inspection substrate 100 is preferably lower than that of the master information carrier 2. This means that if the hardness of the surface of the inspection substrate 100 is higher than the hardness of the master information carrier 2, a foreign substance higher than the hardness of the surface of the master information carrier 2 and lower than the hardness of the inspection substrate 100 is the master information. Carrier 2
If it exists on the surface of the master information carrier 2, or if there is an abnormal protrusion on the master information carrier 2, the hardness of the surface of the testing substrate 100 is higher than the hardness of the foreign matter or the master information carrier 2, and thus the testing substrate 100. There will be no depression on the surface. On the contrary, as shown in the present embodiment, by making the hardness of the surface of the inspection substrate 100 lower than the hardness of the surface of the master information carrier 2, it is possible to surely generate the depression in the inspection substrate 100. Therefore, it is possible to reliably detect the foreign matter or the abnormal protrusion existing on the master information carrier 2.

Further, in this embodiment, the inspection substrate 10 is used.
Although the aluminum substrate is coated with a NiP plating layer as 0, the invention is not limited to this. For example, Co-Re-P, Co-Ni-P, Co-Ni-R.
It may have magnetic properties such as e-P. By applying a plating layer having magnetic properties, the following effects can be obtained. That is, when the magnetic film existing on the surface of the master information carrier 2 has an abnormal protrusion, the magnetic film is peeled off from the surface of the master information carrier 2 by the contact / separation operation. When the plating layer having magnetic characteristics is applied to the surface of the substrate 1, the peeled magnetic layer can be reliably magnetically attracted to the inspection substrate 100 side. The surface of the master information carrier 2 is prevented from being contaminated with the peeled magnetic film.

By adopting the method as described above, it becomes possible to detect abnormal protrusions or foreign matter existing on the surface of the master information carrier with high sensitivity and accuracy.

Next, the flying height of the head is gradually increased by the output V of the defect of the depression detected by the light receiving element of the regular reflection light receiving system 102 and the glide height test which is a known means for the position of the defect. Magnetic disk 1 when lowered and starting to hit with the AE sensor attached to the head
FIG. 20 shows the relationship between the distance d and the distance d from the head.

It can be seen from FIG. 20 that there is a correlation between the output of the defect in the recess detected by the light receiving element of the regular reflection light receiving system 102 and the magnetic disk / head distance. Here, for example, if the flying distance between the magnetic disk / magnetic head of a certain magnetic recording / reproducing apparatus is 20 nm, the detection slice level of the output of the defect of the recess detected by the light receiving element of the regular reflection light receiving system 102, that is, The defect detectable output level is set to a predetermined value lower than Va in FIG. 20,
In the process of ST5, if the detection of the light receiving element of the specular reflection light receiving system 102 is 0, it may be judged as OK, and if it is one or more, it may be judged as NG. When the NG occurs, the defective NG is caused by the abnormal protrusion or the adhering foreign matter of the master information carrier 2. Therefore, the same defect may occur in all the magnetic disks during the magnetic transfer. Therefore, it becomes necessary to observe and remove the defect on the surface of the master information carrier 2 corresponding to the defect position. Regular reflection light receiving system 1 in step ST5
If the detection of the light receiving element 02 is 0, magnetic transfer is performed using the master information carrier 2 that has become OK, and the magnetic disk 1 after magnetic transfer may be incorporated in the drive of the magnetic recording / reproducing apparatus.

By reliably detecting the defect caused by the master information carrier by the above method, it is possible to provide a highly reliable magnetic recording / reproducing apparatus.

(Second Embodiment) Next, a defect inspection method for a master information carrier according to a second embodiment of the present invention will be described with reference to FIGS.

The difference between the first embodiment and the present embodiment is that the area on the master information carrier 2 when the master information carrier 2 and the inspection substrate 100 are in close contact with each other is magnetically transferred to the regular magnetic disk 1. This is the point that the magnetic transfer area at that time is completely included.

FIG. 21 is a diagram for pointing out a problem on which the proposal of the second embodiment is based. That is, it is a diagram for explaining the inconvenience caused by using the inspection substrate 100 having the same size as the magnetic disk 1. FIGS. 21A and 21B are diagrams schematically showing the relationship between the master information carrier 2 and the inspection substrate 100 during suction / pressurization.

In FIG. 15A, the area G is inspected by the inspection by the close contact between the master information carrier 2 and the inspection substrate 100 in the first state. Even if there is a foreign substance outside the area G, the foreign substance remains undetected. The area G corresponds to the outer shape of the magnetic disk 1. Foreign matter adheres to an extremely thin annular area, that is, an extremely thin annular area between the maximum area of the positional deviation in the surface direction and the outer shape of the magnetic disk, but since it is outside the area G, it is transferred to the inspection substrate 100 in the first state. Not done.

Next, when the inspection substrate 100 in the first state is exchanged with the regular magnetic disk 1 and then magnetic transfer is performed, if the inspection substrate 100 and the regular magnetic disk 1 have the same size, they are attached. Due to the displacement of the position, the non-inspected portion where the foreign matter remains contacts with the magnetic disk 1 as shown in FIG. 7B, so that the edge of the magnetic disk 1 may contact the foreign matter. In such a case, the degree of adhesion between the magnetic disk 1 and the master information carrier 2 is reduced in the vicinity of the foreign matter, and the output of the servo signal transferred to the magnetic disk 1 is reduced. As a result, a read error occurs and the rotation of the magnetic disk 1 is disturbed.

Therefore, by using the inspection substrate 100 having a size larger than that of the regular magnetic disk 1, the area G in FIG. 21A is widened, and the magnetic disk 1 and the inspection substrate 100 are separated. Even if the mounting position deviates, normal magnetic transfer can be performed over the entire surface of the magnetic disk, and a high-quality magnetic disk can be manufactured without lowering the servo signal output. in this case,
The master information carrier 2 and the inspection substrate 100 need only be attached once.

By the way, normally, the inspection substrate 100 is one in the middle of the manufacturing process of a regular magnetic disk,
For example, the disk having the aluminum alloy substrate as shown in the first embodiment is often used, and since the sizes are the same, in order to obtain the above effect, when the inspection substrate 100 and the master information carrier 2 are sucked / pressurized. Inspection board 10
A method of eccentricity of 0 may be adopted. It is advantageous in terms of cost.

That is, as shown in FIG. 22, contact / separation is performed a plurality of times, and the contact position of the inspection substrate 100 in the first state with respect to the master information carrier 2 is W, X,
By sequentially shifting like Y and Z, it is possible to inspect an area that completely includes the regular magnetic disk 1. Further, by adopting this method, it becomes possible to further improve the accuracy of the inspection. The contents will be described with reference to FIGS. 23 to 25.

23 to 25 show defect inspection results in the second embodiment.

FIG. 23 is a step of inspecting defects on the surface of the inspection substrate 100 in the first state, that is, S in FIG.
The defect inspection result in the process of T1 is shown.

After the step ST1, the step ST2, that is, the presence or absence of foreign matter of 1 μm or more on the surface of the inspection substrate 100 in the first state is inspected by the defect inspection apparatus. Perform a certain adhesion process. In the process of ST3, the drive unit (not shown) is arranged so that the inspection substrate 100 in the first state is arranged at the W, X, Y, and Z positions shown in FIG. 22 with respect to the guide member 16 in FIG. No) is provided. First, when the master information carrier 2 and the inspection board 100 in the first state are separated from each other as shown in FIG. 1, the inspection board 100 in the first state is indicated by W in FIG.
Of the guide member 1 by the drive unit so as to be arranged at the position
Move 6 Then, the close contact shown in FIG. 2 is performed, and the separation shown in FIG. 1 is performed again. Similarly, the guide member 16 is moved by the driving unit so that the inspection substrate 100 in the first state is arranged at the position X in FIG. 22, contact / separation is performed, and the same is performed at the position Y. , And finally at the Z position. The inspection substrate after contact / separation is the inspection substrate in the second state.

By adopting this method, the inspection substrate 100 in the first state can be brought into close contact with the master information carrier 2 in the area including the close contact area of the magnetic disk 1. That is, due to the positional deviation from the magnetic disk 1,
It is possible to perform an inspection including all the areas H where there is a possibility that foreign matter on the master information carrier 2 outside the area corresponding to the magnetic disk may come into contact with the magnetic disk 1. In FIG. 22, the possibility area H is a concentric circle with respect to the magnetic disk 1. The area shown by black dots in which foreign substances are scattered is an ultrafine annular area (see hatching).

Next, the second step which is the step ST4 in FIG.
A step of inspecting for defects on the surface of the inspection substrate 100 in the state is performed. The result is shown in FIG.

Next, the step of ST5 in FIG. 12, which is a step of determining a defect caused by the master information carrier 2, is performed. The result is shown in FIG. As is clear from this result,
By performing the adhesion of the master information carrier 2 to the inspection substrate 100 in the first state four times while changing the place, the defect caused by the foreign matter or the abnormal protrusion existing on the surface of the master information carrier 2 is eliminated. The inspection substrate 100 is to be detected a plurality of times. As a result, even a defect that may exist in the extra-fine annular region can be reliably transferred to the inspection substrate 100, and inspection omission can be reliably prevented. It is not necessary that the contact direction is changed a plurality of times by changing the contact position at every 90 degrees. For example, it may be performed 45 times or three times at intervals of 120 degrees.

By reliably detecting the defects caused by the master information carrier by the above method, it is possible to provide a highly reliable defect detection method and a magnetic recording / reproducing apparatus.

[0169]

According to the present invention, a master information carrier in which it is difficult to identify a defect such as an abnormal protrusion or a foreign substance because a magnetic film pattern corresponding to an information signal for tracking servo or the like is formed in the first place. In the defect inspection, the existence of the magnetic film pattern is achieved by constructing a unique and exquisite method that does not use the indirect defect inspection as described above and overcomes the problems newly derived from the indirect defect inspection. Therefore, it is possible to perform the defect inspection with high accuracy on the master information carrier in a fatal situation where the defect identification is originally difficult. As a result, it is possible to realize a highly reliable magnetic recording / reproducing device.

[Brief description of drawings]

FIG. 1 is a diagram showing a state in which a master information carrier and a magnetic disk are separated from each other according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a state in which a master information carrier 2 and a magnetic disk according to Embodiment 1 of the present invention are in close contact with each other.

FIG. 3 is a diagram showing a contact surface of a master information carrier with a magnetic disk according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a shape of a boss according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between elapsed time and atmospheric pressure in a close contact space according to the first embodiment of the present invention.

FIG. 6 is a diagram schematically showing a plane of an example of a master information carrier according to the first embodiment of the present invention.

FIG. 7 is an enlarged view of part F in FIG. 6 according to Embodiment 1 of the present invention.

FIG. 8 is a partial cross-sectional view of the region shown in FIGS. 6 and 7 according to the first embodiment of the present invention.

FIG. 9 is a diagram showing initialization in the first embodiment of the present invention.

FIG. 10 is a diagram showing magnetic transfer according to the first embodiment of the present invention.

FIG. 11 is a diagram showing a state during magnetization processing according to the first embodiment of the present invention.

FIG. 12 is a diagram showing a flowchart of a defect inspection process in the first embodiment of the present invention.

FIG. 13 is a diagram showing a defect inspection apparatus according to the first embodiment of the present invention.

FIG. 14 is a diagram showing a defect inspection result in the step ST1 in the first embodiment of the present invention.

FIG. 15 is a diagram showing a defect inspection result in the step ST4 in the first embodiment of the present invention.

FIG. 16 is a diagram showing a flowchart of a process of determining a defect caused by the master information carrier according to the first embodiment of the present invention.

FIG. 17 is a diagram showing barycentric positions of various defects when the same inspection substrate according to the first embodiment of the present invention is continuously measured 20 times.

FIG. 18 is a result of listing defects having a rotational phase shift amount of 10 ° or less and a positional shift amount of 0.5 mm or less among the defects detected by the light receiving element of the regular reflection light receiving system according to the first embodiment of the present invention. Showing

FIG. 19 is a diagram showing a result of subtraction according to the first embodiment of the present invention.

FIG. 20 is a diagram showing the relationship between the output of a defect in a dent detected by the light receiving element of the regular reflection light receiving system and the magnetic disk / head distance according to the first embodiment of the present invention.

FIG. 21 is a diagram schematically showing the relationship when the master information carrier and the inspection substrate according to Embodiment 2 of the present invention are in close contact with each other.

FIG. 22 is a diagram showing a contact position of the inspection substrate with respect to the master information carrier according to the second embodiment of the present invention.

FIG. 23 is a diagram showing a defect inspection result in the step ST1 in the second embodiment of the present invention.

FIG. 24 is a diagram showing a defect inspection result in the process of ST4 in the second embodiment of the present invention.

FIG. 25 is a diagram showing a result of subtraction according to the second embodiment of the present invention.

FIG. 26 is a view showing a result of observing a magnetic disk surface after conventional magnetic transfer.

FIG. 27 is a sectional view of a depressed portion of a conventional magnetic disk.

FIG. 28 is a diagram showing a result of optically measuring the state of protrusions on the entire surface of the magnetic recording medium after magnetic transfer is performed by a conventional magnetic transfer method.

[Explanation of symbols]

2 master information carrier 100 inspection substrate 101 laser light transmission system 102 specular reflection light reception system 103 scattered light reception system 104 data processing device ST1 step ST2 for inspecting defects on the surface of the inspection substrate in the first state ST2 in the first state Step ST3 of inspecting for foreign matter on the surface of the inspection substrate ST3 Step of adhering ST4 Step of inspecting defects on the surface of the inspection substrate in the second state ST5 Step of discriminating defects caused by the master information carrier

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP 2001-176065 (JP, A) JP 2002-269739 (JP, A) JP 2001-307323 (JP, A) JP 2001-357523 (JP, A) JP 2001-167434 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 5/84 G11B 5/86 G01N 21/95

Claims (19)

(57) [Claims] 1. A method for inspecting a defect of a master information carrier having a magnetic film pattern corresponding to an information signal to be magnetically transferred to a magnetic recording medium, wherein the defect on the master information carrier is in a first state. A step of inspecting a defect that may originally exist on the inspection substrate in the first state, and a master information carrier for the defect-inspected inspection substrate in the first state. A step of closely contacting and transferring a defect that may exist on the master information carrier to the inspection substrate for which the defect inspection has been completed; and an inspection of a second state corresponding to the defect transfer separated from the master information carrier. The inspection board for defects in the second state, the defect inspection result for the inspection board in the second state, and the defect inspection result for the inspection board in the first state. Defect inspection method of the master information carrier which comprises a step of determining a defect that may be present in the master information on a carrier by comparing with. 2. A defect inspection for the inspection substrate in the first state between the defect inspection process for the inspection substrate in the first state before the adhesion process and the adhesion process. Inspecting whether the number of defects or the size of the defects is less than or equal to a predetermined value, when the value exceeds a predetermined value, the process is interrupted, and when the value is less than or equal to the predetermined value, a step of advancing to the adhesion step is added The defect inspection method for a master information carrier according to claim 1, wherein 3. A defect inspection for the inspection substrate in the first state between a defect inspection process for the inspection substrate in the first state before the adhesion process and the adhesion process. In, inspect for the presence of defects of a predetermined value or more, if there are more than a predetermined number of defects, interrupt the process,
The method of inspecting a defect of a master information carrier according to claim 1, wherein a step of advancing to the step of adhering is added when the step does not exist. 4. The defect inspection method for a master information carrier according to claim 3, wherein the predetermined value is 1 μm. 5. The step of inspecting the inspection substrate in the first state includes a work of measuring a rotational phase of the inspection substrate in the first state with respect to a defect inspection means, and the inspection state in the second state. The step of defect inspection on the substrate includes an operation of measuring the rotation phase of the inspection substrate in the second state with respect to the defect inspection means, and the step of defect determination on the master information carrier through the comparison is the operation of the comparison. 5. The defect inspection method for a master information carrier according to claim 1, further comprising the step of correcting the shift between the two rotation phases. 6. The correction of the rotational phase, wherein the rotational phase of a defect detected based on the detection of specular reflection light from the inspection substrate when the inspection substrate is irradiated with light is corrected. The defect inspection method for a master information carrier according to claim 5. 7. The rotational phase is corrected by correcting the rotational phase of a defect detected based on detection of scattered light from the inspection substrate when the inspection substrate is irradiated with light. The defect inspection method for a master information carrier according to claim 5. 8. In the correction of the rotational phase, the rotational phase of a defect detected based on detection of specularly reflected light or scattered light from the inspection substrate when the inspection substrate is irradiated with light is corrected. 6. The method for inspecting a defect of a master information carrier according to claim 5, characterized in that the rotation phase correction of the defect of the detection of the specular reflection light is prioritized. 9. The defect inspection step for the inspection substrate in the first state counts the number of defects on the inspection substrate in the first state, and for the inspection substrate in the second state. The step of defect inspection is to count the number of defects on the inspection substrate in the second state, and the step of defect determination on the master information carrier through the comparison is the inspection substrate in the first state. And the defect count of the inspection substrate in the second state are judged to be the same. If they are the same, it is judged that there is no defect in the master information carrier, and if they are different, it is judged that there is a defect. The defect inspection method for a master information carrier according to any one of claims 1 to 8. 10. The defect inspection step for the inspection substrate in the first state is to extract positional information of a defect on the inspection substrate in the first state, and the inspection substrate in the second state. In the defect inspection step for extracting defect position information on the inspection substrate in the second state, and the defect determination step on the master information carrier through the comparison is performed in the first state inspection step. It is determined whether the position information of the defect regarding the inspection substrate and the position information of the defect regarding the inspection substrate in the second state are the same. If they are the same, it is determined that there is no defect in the master information carrier, and if they are different, there is a defect. The method for inspecting a defect of a master information carrier according to any one of claims 1 to 8, which is a method for determining a defect. 11. When a defect is continuously judged over a plurality of minute unit areas in which the entire area of the inspection substrate is divided into a large number, the continuous plurality of unit areas are regarded as one area, and are regarded as one area. 11. The defect inspection method for a master information carrier according to claim 10, wherein the center of gravity of the area or its vicinity is used as the position information of one defect. 12. The inspection substrate is a substrate having a size corresponding to a maximum area of the surface misregistration in consideration of the surface misalignment when the master information carrier is in close contact with the master information carrier. The defect inspection method for a master information carrier according to any one of claims 1 to 11. 13. The inspection substrate having substantially the same size as the magnetic recording medium is used, and when the master information carrier and the inspection substrate are in close contact with each other, when the master information carrier is in close contact with the master information carrier. In consideration of the positional deviation in the surface direction, the master information carrier is arranged so that the inspection substrate having substantially the same size as the magnetic recording medium comes into close contact with the entire maximum area of the master information carrier having the positional deviation in the surface direction. The contact position between the inspection substrate and the inspection substrate is changed so that the both are adhered a plurality of times.
1. A method for inspecting a defect of a master information carrier according to any one of 1 to 1. 14. The inspection substrate, which is made of a material whose main component is a main component of the magnetic recording medium, is used.
A method for inspecting a defect of a master information carrier as described in any one of 1 above. 15. The defect of the master information carrier according to any one of claims 1 to 14, wherein the inspection substrate has a hardness lower than that of the master information carrier. Inspection method. 16. The inspection substrate according to claim 1, wherein the lubricant applied on the magnetic recording medium is the lubricant omitted. Defect inspection method for master information carrier. 17. The defect inspection method for a master information carrier according to claim 1, wherein the inspection substrate has a magnetized surface on the contact side. 18. The magnetic property in the master information carrier is obtained by using the master information carrier which has been defect-inspected by the defect inspection method of the master information carrier according to any one of claims 1 to 17 and which is determined to be non-defective. A method of magnetically transferring an information signal according to a film pattern onto a magnetic recording medium, wherein the surface of the master information carrier on which the magnetic film pattern is formed is brought into close contact with the magnetic recording medium, and an external magnetic field is applied. A magnetic film pattern magnetic transfer method using a master information carrier, wherein an information signal based on the magnetic film pattern of the master information carrier is magnetically transferred to the magnetic recording medium. 19. The magnetic property of the master information carrier is determined by using the master information carrier which has been defect-inspected by the defect inspection method of the master information carrier according to any one of claims 1 to 17 and which has been determined to be non-defective. A method of magnetically transferring an information signal according to a film pattern onto the magnetic recording medium, wherein the magnetic film pattern of the master information carrier is magnetized in advance to form the magnetized magnetic film pattern of the master information carrier. A magnetic film pattern magnetic transfer method using a master information carrier, characterized in that an information signal based on the magnetic film pattern of the master information carrier is magnetically transferred to the magnetic recording medium by bringing the surface of the other side into close contact with the magnetic recording medium. .