JP3488643B2 - Optical information recording medium and mastering method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writable optical information recording medium such as a phase change optical disk and a mastering method thereof.

[0002]

2. Description of the Related Art Generally, in a writable optical information recording medium of this kind, a sync signal and address information for position search (hereinafter, these information are referred to as "preformat information").
Is formed in advance as a phase groove on the disk substrate. As a method of forming such preformat information as a phase groove, a method of wobbling the groove and a length, interval, position of a discontinuous groove (hereinafter, this groove is referred to as “phase pit”) are set. There is a method to change.

In order to increase the recording capacity of an optical disk, the interval between the grooves serving as information recording tracks (hereinafter,
If this distance is made narrower (referred to as "track pitch"), a sufficient C / N cannot be obtained by the wobbling method, and the recording capacity is also limited.

Therefore, Japanese Patent Application Laid-Open No. 9-17029 proposes to form a phase pit on a land located between the grooves. FIG. 11 schematically shows an optical information recording medium of this idea, in which a phase pit P is formed on a land L which is a portion between the grooves G. As shown in the figure, the phase pit P has a shape in which the grooves G of adjacent tracks are connected to each other, that is, a ladder shape.

On the other hand, as a method of reproducing such a phase pit P, a photodiode divided into two in the radial direction of the optical disk (direction orthogonal to the track direction) is arranged in the light receiving system, and this photodiode is subjected to photoelectric conversion. There is a method of detecting it as a difference signal of the signals thus obtained (for details, refer to FIG. 8 and the corresponding description in JP-A-9-17029). Further, when the phase pits P are present on both the lands L located on the left and right of the groove G, the preformat information is simultaneously read and interferes (crosstalk), so that the phase pits P are formed. Two types of preformat information patterns are prepared for even-numbered EVEN and odd-numbered ODD, and these patterns are switched and used in the case of an arrangement in which crosstalk occurs (the same publication). See FIG. 2 and corresponding description therein). This approach eliminates the problem of crosstalk.

[0006]

In the above-mentioned publication, two types of patterns of preformat information formed by the phase pits P are prepared for the crosstalk problem, and the patterns are arranged when the crosstalk occurs. Since they are switched and used, it can be said to be effective as a means for solving the crosstalk problem.

However, while detecting the position where the crosstalk occurs (that is, the position where the phase pits P exist at the lands L located on the left and right across the groove G at the same time) during exposure of the master, the even pattern for even numbers and the odd number for odd numbers are detected. It can be said that it is technically very difficult to perform exposure by changing over the ODD pattern for use. That is, if there is no error in the rotation speed of the exposure master, it is possible to encode the phase pit pattern of the pre-format information in which the even-numbered EVEN pattern and the odd-numbered ODD pattern are switched by calculating the position where the crosstalk occurs. However, there is an error (generally 0.1% or less) in the rotation speed of the exposure master,
It is not possible to use the calculation method. Therefore, in practice, it is necessary to detect the position where crosstalk occurs while monitoring the number of revolutions of the exposure master, and switch between the even EVEN pattern and the odd ODD pattern for exposure. However, since the length of the phase pit P in the track direction is on the order of submicrons and is extremely short, it is necessary to detect the error in the rotational speed on the order of at least ns.
The error that the rotation speed detection device itself has also causes an error in the position detection where the crosstalk occurs.

Although not described in detail in the above-mentioned publication, as a method for reproducing the preformat information formed by the phase pits P, a push-pull signal (P
There is a method using a ush-Pull signal = difference signal. The reproducing principle will be described with reference to FIGS. 12 and 13. 12
FIG. 6B shows the waveform of the push-pull signal generated near the ladder-shaped phase pit P when the reproduction beam B crosses the disc radial direction as shown in FIG. The push-pull signal in this case is a sine wave having the track pitch TP as one cycle, but in the ladder-shaped portion where the phase pits P are present, the radial cross-sectional shape is asymmetric with respect to the track center indicated by the broken line. The center of the phase pit P (indicated by a one-dot chain line in the figure) is displaced from the track center of the groove G by a dimension s in the radial direction. Therefore, FIG.
When a signal is reproduced while tracking control is performed along the groove G as shown in (a), the peak of the push-pull signal as shown by the magnitude A is shown at the position of the phase pit P as shown in (b) of the same figure. Therefore, if the presence or absence of a peak such as A or the occurrence position is detected, the phase pit P
It is possible to reproduce the pre-formatted information formed in. FIG. 14 shows an example of the signal waveform of the phase pit P in this system.

However, at the location where the phase pits P simultaneously exist on the lands L located on the left and right sides of the groove G (the cross-sectional positions of the tracks Tr3 and Tr4 shown in FIG. 11B, see FIG. 15A). The presence of the phase pit P does not make the radial cross-sectional shape of the ladder portion asymmetrical (the shift s does not occur at the center of the phase pit P as can be seen from the push-pull signal in FIG. 15B). ), A peak like A does not occur in the push-pull signal when the signal is reproduced while tracking control is performed along the groove G. That is, when the phase pits P are simultaneously present on the lands L located on the left and right sides of the groove G, the problem that the preformat information formed by the phase pits P cannot be detected occurs. Therefore, in order to solve this problem, even when reproducing with a push-pull signal, two types of patterns of the preformat information formed by the phase pits P, that is, even EVEN and odd ODD are prepared, and crosstalk occurs. In the case of such an arrangement, it is necessary to switch and use these patterns.

Further, when information is recorded in the groove G, the radial spread of the recording mark M is the groove G and the land L.
It is known to be cut off at the wall with. When recording is performed in the vicinity of the phase pit portion formed as in the above-mentioned publication example, the recording mark M spreads toward the phase pit P formed on the land L as shown in FIG.
The phenomenon of sticking out occurs. This protrusion phenomenon adversely affects the phase pit signal, and is shown in FIG.
As in the case shown in (d), the phase pit signal is distorted or the signal amplitude is reduced. As a result, there is a fatal problem that the phase pit P cannot be detected during reproduction and the address information cannot be reproduced.

By the way, as described above, even when the phase pits P are simultaneously present on the lands L located on the left and right of the groove G, the preformat information formed by the phase pits P can be detected. This optical information recording medium has been proposed by the present applicant as Japanese Patent Application No. 9-230696. FIG. 17 shows an example thereof, in which the phase pits P are always formed in an asymmetric shape in the radial direction. That is, the phase pits P are not completely formed in a ladder shape and have a length shorter than the track pitch.
FIG. 18 shows an example of the signal waveform of the phase pit P. According to this proposed example, even if there is a phase pit in the adjacent track, the track center of the phase pit and the track center of the groove G are always displaced by s, and the phase pit P can be detected. However, also in the case of this proposed example, the same problem occurs with respect to the spread of the recording mark M at the time of recording described above.

Therefore, according to the present invention, even if phase pits are present on the lands located on the left and right sides of the groove, they are not interfered with, and even after recording, the address information and the like formed by the phase pits are accurately reproduced. It is an object of the present invention to provide an optical information recording medium that can be used.

Furthermore, the present invention provides a mastering method for an optical information recording medium, which can achieve good results by clarifying the mastering conditions of the groove and phase pits of the optical information recording medium which can achieve the above object. The purpose is to

[0014]

According to another aspect of the present invention, there is provided an optical information recording medium, wherein an information recording track is a groove.
An optical information recording medium preformat information is formed as a phase pit, attention phase pit for the target groove has the same groove depth as the groove groove depth, the watch
The Heidelberg <br/> Lube be adjacent to the target phase pit side of the eye grooves between Rutotomoni the target groove connected radially are shaped partition wall occurs in the radial direction.

Therefore, since the partition wall is not directly connected to the target groove and the target phase pit in the target track, the phase pits exist on the lands located on the left and right sides of the groove, so that interference occurs. Of course, due to the effect of the partition wall, the stable phase pit signal can be obtained without deterioration of the phase pit signal after recording, and the address information can be reproduced correctly.

According to a second aspect of the present invention, the radial width Δ of the partition wall and the track pitch TP in the optical information recording medium according to the first aspect satisfy the relationship of Δ / TP ≧ 0.1.

Therefore, since the radial width Δ of the partition wall is set to a range capable of blocking the spread of the recording mark, the partition wall effect can be surely exhibited and the deterioration of the phase pit signal after recording can be prevented. .

According to a third aspect of the present invention, in the optical information recording medium of the first aspect, the width Wp of the phase pit, the circumferential length Lp, the track pitch TP, and the spot diameter BD of the recording / reproducing beam are: , Lp / BD <1.0, 0.
The relationship of 8 ≦ Wp / TP ≦ 0.9 is satisfied.

Therefore, since the width Wp of the phase pit is set within the range in which the signal amplitude of the phase pit can be made sufficiently large, a stable phase pit signal can be obtained and the address information can be reproduced correctly.

According to a fourth aspect of the invention, in the optical information recording medium according to the first aspect, the width Wp of the phase pit, the circumferential length Lp, the track pitch TP, and the spot diameter BD of the recording / reproducing beam are: , 1.0 ≦ Lp / BD, 0.
The relationship of 5 ≦ Wp / TP ≦ 0.8 is satisfied.

Therefore, the length Lp of the phase pit in the circumferential direction is
Is set within a range in which the signal amplitude of the phase pit can be made sufficiently large, so that a stable phase pit signal can be obtained and the address information can be correctly reproduced.
According to a fifth aspect of the invention, in the optical information recording medium according to the first aspect, the width Wp of the phase pit, the circumferential length Lp thereof, the track pitch TP, and the spot diameter BD of the recording / reproducing beam are 1. 0 ≦ Lp / BD, 0.8 ≦ Wp / T
The relationship of P ≦ 0.9 is satisfied.

Therefore, since the width Wp of the phase pit and the length Lp in the circumferential direction thereof are set within the range in which the signal amplitude of the phase pit can be made sufficiently large, a stable phase pit signal can be obtained and the address can be obtained. Information can be reproduced correctly.

A mastering method for an optical information recording medium according to a sixth aspect of the invention is a method for mastering a groove and a phase pit in the optical information recording medium according to any one of the first to fifth aspects. Two exposure beams, one for the groove and one for the phase pit, are used for mastering. The spot diameter of the exposure beam for the groove is BD1, the spot diameter of the exposure beam for the phase pit is BD2, and these two exposure beams are used. Where L is the spot interval and Δ is the radial width of the partition wall, Δ = L- (BD1 / 2)-(B
The relationship of D2 / 2) is satisfied.

Therefore, since the mastering condition can be determined by calculation, the radial width Δ of the partition wall can be adjusted to an arbitrary value.

According to a seventh aspect of the present invention, in the mastering method of the optical information recording medium according to the sixth aspect, the size of the spot diameters BD1 and BD2 is fixed, and either one of the two exposure beams is used. The angle of incidence of the exposure beam of (1) on the objective lens was changed by the light deflection element to adjust the spot interval L.

Therefore, it is possible to easily and accurately change and adjust the width Δ of the partition wall in the radial direction.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. Note that, also in this embodiment,
A groove serving as an information recording track is indicated by G, a land between the grooves G is indicated by L, and a phase pit indicating preformat information is indicated by P. The groove width of the groove G is Wg, and the groove width of the phase pit P is Wp.

In the optical information recording medium of the present embodiment, basically, the phase pits P are not completely formed in a ladder shape as shown in FIG. 1, but are formed with a length shorter than the track pitch. Thus, the track center of the phase pit P and the track center of the groove G are displaced by s.
That is, it has almost the same configuration as the already proposed example shown in FIG.

Here, in the present embodiment, FIG.
As shown in, certain tracks to be recorded / played back
(1) The groove G (attention groove) and the phase pit (1) (attention phase pit P) arranged on the same track are not connected in the radial direction, and the partition wall 1 exists. The phase pit (1) is formed in a shape that is connected to the groove G (adjacent groove) of the track (3) adjacent to the phase pit (1) side of the track ( 1) . By the way, in the case of the proposed example of FIG. 17, as shown in FIG.
A groove G (a target groove) of a certain track (1) (a target track) to be recorded / reproduced and a phase pit (1) (a target phase pit P) arranged on the same track are connected in the radial direction. The groove G of the adjacent track
It is formed in such a shape that there is a partition wall between and.
That is, the direction of the phase pit P with respect to the radial direction is opposite to that of the present embodiment and the proposed example.

In such a structure, the track (1)
2 is reproduced in the direction indicated by the arrow in FIG. 2, the peak of the push-pull signal generated from the phase pit P has a polarity (indicated by the direction of the peak on the paper surface) of the case of the already proposed example shown in FIG. Appear the same. The polarity of the peak is a signal that is determined depending on which of the left and right sides the phase pit P exists with respect to the groove G. Therefore, although there is a difference in the presence or absence of the partition wall 1, the phase pits P are arranged on the same side with respect to the groove G in the case of the present embodiment and the case of the already proposed example. As in the case, it is possible to maintain the advantage that the polarities of the peaks are the same. Therefore, basically, even when the phase pits P are simultaneously present on the lands L located on the left and right of the groove G, the pre-format information formed by the phase pits P can be detected.

Further, as an effect of the partition wall 1, as shown in FIG. 3, the recording mark M recorded to the groove G of the track (1) indicates the address information of the track (1) to be the recording and reproducing It is prevented from spreading to the phase pit (1) side. That is, the recording mark M as described in FIG.
Does not protrude to the side of the phase pit P. However,
In FIG. 2, when the recording mark is recorded on the groove G of the track (3) adjacent to the track (1) , the recording mark protrudes into the phase pit (1). Since the track pitch TP is used, the recording mark portion protruding in the phase pit (1) when reproducing the track (1) is located at the hem portion where the light intensity of the reproduction beam is not present. The influence of the signal (crosstalk signal) leaking from the adjacent track is low, and the deterioration of the phase pit signal as shown in FIGS. 16B to 16D does not occur. In this manner, according to the present embodiment, the phase pit signal after recording does not deteriorate due to the effect of the partition wall 1, and a stable phase pit signal is obtained, so that the address information can be correctly reproduced.

Some devised examples of the basic configuration example of the present embodiment will be described below.

Inventive Example 1 This embodiment shown in FIG. 2 and FIG.
When the track (1) is reproduced when the groove G and the phase pit P are arranged as in the case of the already proposed example shown in FIG. 8, a push-pull signal generated from the phase pit (1) and the phase pit (2). The peak polarities of are opposite to positive and negative. Further, the peak value (amplitude of the phase pit signal) is larger in the arrangement in which the groove of the reproduction track and the phase pit are connected (the phase pit is closer to the track center of the groove G). Therefore, in FIG. 18, the phase pit
The signal amplitude of (1) is A1, and the signal amplitude of the phase pit (2) is A2.
Then, there is a relation of A1> A2. On the other hand, in FIG. 2 showing the present embodiment, if the signal amplitude of the phase pit (1) is B1 and the signal amplitude of the phase pit (2) is B2, then B1
<B2, and the magnitude relationship of the signal amplitude is opposite to that in the case of FIG.

Here, tentatively, in FIGS. 2 and 18, the shapes (groove depth and groove width) related to the groove G and the phase pit P.
Are the same, the relationship of A1 = B2 and A2 = B1 is established. If the track of interest to be recorded / reproduced is track (1) , A1> B1. As described above, in the case of the present embodiment, the phase pit P is located farther in the radial direction than the track center of the groove G to be recorded and reproduced as compared with the case of FIG. May be lower than in the case of FIG. In FIG. 4, the circumferential length Lp of the phase pit P and the spot diameter BD of the recording / reproducing beam are Lp / B.
20 is a graph showing the phase pit signal amplitudes in the case of FIG. 18 (the proposed method is the conventional method (2)) and in the case of FIG. 2 in the case of D = 0.5. The phase pit signal amplitude in FIG. 4 indicates a numerical value obtained by dividing the push-pull signal output value B1 in FIG. 2 by the sum signal Rf and normalizing the value. It can be seen that in the state where the phase pit P is not completely connected to the groove G (range where Wp / TP <1), the phase pit signal amplitude is lower in the case of FIG. 2 showing the present embodiment.

In this respect, according to FIG. 4, in the case of FIG. 2, the state where the phase pit is connected to the adjacent groove (Wp / TP
= 1), the phase pit signal amplitude becomes maximum. Conditions for providing the partition wall 1 for blocking the spread of the recording mark M (Wp / TP
In the range of <1), the phase pit signal amplitude decreases. In the experiment, the radial width Δ of the partition wall 1 (see FIG. 6) is at least Δ / TP = 0.1 (Wp / TP =
It was confirmed that the presence of 0.9) can prevent the recording mark M from spreading. Therefore, also in the present embodiment,
If Δ / TP = 0.1 is set, Wp /
It can be seen that in the vicinity of TP = 0.9, there is not much difference between the phase pit signal amplitudes as compared with the case of FIG. As a result, it is possible to minimize the decrease in the phase pit signal amplitude in this embodiment.

Inventive Example 2 As in Inventive Example 1, if Wp / TP = 0.9 is set, a decrease in phase pit signal amplitude can be suppressed. But,
On the other hand, since the width Δ of the partition wall 1 is very narrow, it is difficult to form a stable groove in the mastering process. From the viewpoint of ease of mastering, Wp / TP = 0.6
It is desirable to set it to about 0.9. However, Wp
As can be seen from FIG. 4, the decrease in the amplitude of the phase pit signal is too large only by setting /TP=0.6 to 0.9. Therefore, it is necessary to take measures to compensate for the decrease. In this case, it can be dealt with by setting Lp / BD ≧ 1.0. Figure 5
This point will be explained with reference to. This Figure 5 shows Wp / TP =
6 is a graph showing a change in the amplitude of the phase pit signal when the ratio of the circumferential length Lp of the phase pit P to the spot diameter BD is changed, taking the case of 0.7 as an example. The phase pit signal amplitude in FIG. 5 also indicates a value obtained by dividing the push-pull signal output value B1 in FIG. 2 by the sum signal Rf and standardizing it. According to this graph, Lp / BD ≧
It can be seen that by setting 1.0, a phase pit signal having a large amplitude can be stably obtained, and the problem of a decrease in phase pit signal amplitude can be avoided. Moreover, according to such conditions, the manufacturing margin in the mastering process is increased,
A manufacturing process of an optical information recording medium with high yield can be provided.

Device 3 In consideration of these points, in order to obtain the largest phase pit signal amplitude, Wp / TP = 0.9 (Device 1) and L
It can be said that the combination condition should be p / BD ≧ 1.0 (invention example 2). However, this combination alone may reduce the manufacturing margin in the mastering process. In this devised example 3, a mastering method (master exposure method) for adjusting the width Δ of the partition wall 1 with high accuracy will be clarified with reference to FIGS. 6 and 7.

In FIG. 6, the section (1) is a region where the groove G and the phase pit P exist, and the section (2) is the groove G.
Indicates the region where only exists. Groove G and phase pit P
In the area where and exist at the same time, the resist master 2 is exposed by using the two exposure beams for the groove and the phase pit at the same time.
In the region where only the resist exists, the resist master 2 is exposed using only the groove exposure beam. At this time, the width of the partition wall 1 in the radial direction is Δ, the spot interval between the two exposure beams is L, and the spot diameter of the exposure beam for the groove is BD.
1. The spot diameter of the exposure beam for the phase pit is BD2
(See FIG. 7) Since the groove width formed by mastering and the spot diameter of the master exposure beam are almost equal,
It can be seen that the relationship Δ = L- (BD1 / 2)-(BD2 / 2) holds. From this relational expression, the spot diameters BD1 and BD of the exposure beam for the groove and the exposure beam for the phase pit and the spot distance L between them may be appropriately selected for the required width Δ of the partition wall 1. I understand. This relational expression can be applied to the above-mentioned device examples 1 and 2.

In order to secure the manufacturing margin in such a mastering process, it is important that the width Δ of the partition wall 1 can be adjusted arbitrarily and with high accuracy. Generally, in order to adjust the spot diameter of the laser beam, a method of changing the diameter of the beam incident on the objective lens is used. According to the exposure optical system shown in FIG. 8, after the beam emitted from the laser light source 3 is split into the groove exposure beam and the phase pit exposure beam by the polarization beam splitter 4, the groove exposure beam is The resist film 9 of the resist master 2 is irradiated through the beam expander 5, the deflection prisms 6, 7 and the objective lens 8, and the exposure beam for the phase pit passes through the deflection prism 10 and the optical modulator 11, and then the beam expander. The resist 9 on the master 2 is irradiated with light through the panda 12, the deflection prisms 13, 6, 7 and the objective lens 8. Here, the beam diameter is widened or narrowed by using means such as the beam expanders 5 and 12. However, in this case, the influence of the deviation of the laser optical axis is large and the accuracy of adjusting the width Δ of the partition wall 1 is improved. It is difficult to raise. In this respect, in this devised example 3, the spot diameters BD1 and BD2 of the two exposure beams are
Is fixed, and the incident angle to the objective lens 8 is provided by interposing the optical deflecting element 14 in the optical path of one exposure beam (for example, the groove side is shown, but it may be the phase pit side). The spot interval L is adjusted by changing the. According to this, the width Δ of the partition wall 1 can be adjusted easily and with high accuracy only by changing the voltage value for the light deflection element 14.

[0040]

EXAMPLES A concrete manufacturing method of the optical information recording medium based on the above description and the resulting products will be described as Examples 1 and 2.

Example 1 Generally, a plastic substrate of such an optical information recording medium is mass-produced by injection molding from a mold called a stamper. The stamper is manufactured according to the stamper manufacturing process (mastering) shown in FIG. In this process, first, the photoresist film 9 is applied to the glass substrate 15 and baked to manufacture the resist master 2 (resist master manufacturing step ... FIG. 9A). Next, resist master 2
Focused laser beam, here, an Ar laser 3
(See FIG. 8) to form a latent image (master exposure step ... FIG. 9B). The exposed resist master 2 is developed to form a groove pattern 16 on the photoresist film 9 (developing step ... FIG. 9C). A Ni film is sputtered on the surface of the resist master 2 having the groove pattern 16 formed on the photoresist film 9 to form a conductive film 17 (conductive film processing step ... FIG. 9D). This conductive film 17
Ni is laminated on the top to form the Ni electroformed plate 18 (Ni electroforming step ... FIG. 9E). The Ni electroformed plate 18 is peeled from the glass substrate 15, and the stamper 19 is completed through cleaning, back surface polishing, and inner / outer diameter processing (peeling, cleaning, back surface polishing, processing step ... FIG. 9 (f)).

Here, FIG. 10 shows a model of the master exposure process shown in FIG. 9B. In this master disc exposure, the resist master disc 2 is laterally fed while being rotated by the turntable 20, and the laser beam of the Ar laser 4 is condensed and irradiated onto the resist master disc 2, whereby the groove pattern 16 for the groove is formed.
Are formed in a spiral shape. Reference numeral 8 is an objective lens.

Regarding the master exposure performed on such a principle, when the master G is exposed to the groove G including the phase pits P as in the devises 1, 2, and 3 in the above-described embodiment,
As described in FIG. 8, two exposure beams for the groove and the phase pit are used. These two exposure beams are arranged so as to be displaced in the radial direction, and at the same time, the resist master 2
The master is exposed by focusing it on top. Therefore, during master exposure, the address information corresponding to the groove being exposed (target groove) is recorded by the phase pits (target phase pits) simultaneously exposed to the master. Further, since the spiral continuous groove is formed, the exposure beam for the groove is continuously irradiated onto the resist master 2, but the exposure beam for the phase pit is provided only at the portion where the phase pit P is arranged. It is irradiated intermittently (ON / OFF control is performed by the optical modulator 11).

An optical information recording medium as described in Deviation Example 2 was produced by using such a method, and its evaluation was performed. Here, the groove depth of the groove G and the phase pit P is about 600Å, the groove width Wg of the groove G is about 0.3 μm, the groove width Wp of the phase pit P is about 0.5 μm, and The length Lp is about 1 μm, the track pitch TP is 0.74 μm, and the radial width Δ of the partition wall 1 is about 0.2 μm.
And In addition, the wavelength of the semiconductor laser for recording and reproduction is set to 63
The objective lens 8 has a numerical aperture NA of 0.60 and a recording / reproducing beam spot diameter of about 0.8 μm. Further, as a recording material of the optical information recording medium, a phase change material (A
gInSbTe) was used. As a result, regarding such an optical information recording medium, the phase pit signal amplitude is 0.2
It was confirmed that the strength was obtained to some extent, the waveform of the phase pit signal amplitude was not distorted even after recording, and the address information could be stably reproduced.

Embodiment 2 Here, an actual mastering condition in the case of Device 3 will be described. The groove depth of the groove G and the phase pit P is about 600Å, the groove width Wg of the groove G is about 0.3 μm,
The groove width Wp of the phase pit P is about 0.65 μm, the circumferential length Lp of the phase pit P is about 1 μm, and the track pitch T
P is 0.74 μm, and the radial width Δ of the partition wall 1 is about 0.1.
μm. As a mastering condition at this time, the spot diameter BD1 of the exposure beam for the groove and the spot diameter BD2 of the exposure beam for the phase pit are substantially equal to each other and are about 0.
The spot interval L was about 0.4 μm at 3 μm. Also,
The wavelength of the semiconductor laser for recording / reproducing was 635 nm, the numerical aperture NA of the objective lens 8 was 0.60, and the beam spot diameter for recording / reproducing was about 0.8 μm. Further, as a recording material of the optical information recording medium, a phase change material (AgInSbTe) is used.
Was used. As a result, with respect to such an optical information recording medium, a strength of about 0.35 is obtained as the phase pit signal amplitude, the waveform of the phase pit signal amplitude is not distorted even after recording, and the address information can be stably reproduced. It could be confirmed.

[0046]

According to the first aspect of the present invention, since a partition is not directly connected between the target groove and the target phase pit in the target track, the lands located on the left and right sides with the groove interposed therebetween. Even if there is a phase pit on the upper side, interference is not received, and due to the effect of the partition wall, a stable phase pit signal can be obtained without deterioration of the phase pit signal after recording, and the address information is reproduced correctly. Can be made.

According to the second aspect of the present invention, since the radial width Δ of the partition wall is set to a range capable of blocking the spread of the recording mark, the partition wall effect can be surely exhibited, and the phase pit signal after recording can be achieved. Can be prevented from deteriorating.

According to the third aspect of the present invention, the width Wp of the phase pit is set within the range in which the signal amplitude of the phase pit can be made sufficiently large, so that a stable phase pit signal can be obtained and the address information can be correctly obtained. Can be played.

According to the invention described in claim 4, since the length Lp in the circumferential direction of the phase pit is set within the range in which the signal amplitude of the phase pit can be made sufficiently large, a stable phase pit signal can be obtained. , The address information can be reproduced correctly. According to the invention of claim 5, the width Wp of the phase pit and the length Lp in the circumferential direction thereof are set within a range in which the signal amplitude of the phase pit can be made sufficiently large, so that a stable phase pit signal is obtained. The address information can be reproduced correctly.

According to the sixth aspect of the invention, when mastering the optical information recording medium according to any one of the first to fifth aspects, the mastering condition can be determined by calculation. The width Δ of can be adjusted to an arbitrary value.

According to the seventh aspect of the invention, in the mastering method for the optical information recording medium according to the sixth aspect, the adjustment of the width Δ of the partition wall in the radial direction can be easily and accurately performed.

[Brief description of drawings]

FIG. 1 shows an optical information recording medium according to an embodiment of the present invention, in which (a) is a plan view, (b) is a cross-sectional view at position (1) , and (c) is at position (2) . FIG.

FIG. 2 is a schematic diagram showing the relationship between phase pits and phase pit signal waveforms.

FIG. 3 is a schematic diagram for explaining the effect of the partition wall.

FIG. 4 is a graph showing the relationship between the width of a phase pit and the phase pit signal amplitude.

FIG. 5 is a graph showing the relationship between the length of a phase pit and the phase pit signal amplitude.

6A and 6B show a master exposure method for phase pits, FIG. 6A is a plan view, and FIG. 6B is an explanatory view of an exposure beam of an exposure beam;
(C) is a sectional view of the exposure state at the position (1 ) of (a),
(D) is a sectional view of the exposure state at the position (2 ) of (a).

FIG. 7 is an explanatory diagram showing spot diameters and spot intervals of two exposure beams.

FIG. 8 is a configuration diagram showing an optical system for exposing a master.

FIG. 9 is a process diagram showing a stamper manufacturing process.

FIG. 10 is a perspective view showing a master exposure model.

11A and 11B show a conventional optical information recording medium, where FIG. 11A is a plan view, FIG. 11B is a sectional view at a position (1) , and FIG. 11C is a sectional view at a position (2) .

FIG. 12 shows the principle of phase pit reproduction, (a) is a plan view and (b) is a waveform diagram of a push-pull signal.

13A and 13B show a principle of reproducing a phase pit accompanying tracking, wherein FIG. 13A is a plan view and FIG. 13B is a waveform diagram of a push-pull signal.

FIG. 14 is a schematic diagram showing the relationship between the phase pit and the phase pit signal waveform.

FIG. 15 shows a case where a phase pit cannot be reproduced,
(A) is a plan view and (b) is a waveform diagram of a push-pull signal.

FIG. 16 is an explanatory diagram showing distortion of a phase pit signal waveform due to recording mark protrusion.

FIG. 17 shows an optical information recording medium of an already proposed example, (a) is a plan view, (b) is a sectional view at a position (1) , and (c) is a sectional view at a position (2) .

FIG. 18 is a schematic diagram showing the relationship between the phase pit and the phase pit signal waveform.

[Explanation of Codes] 1 Partition 14 Optical Deflection Element G
Groove P Phase pit Wg Groove groove width Wp Phase pit groove width Lp Phase pit length

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Claims (7)

(57) [Claims] 1. An optical information recording medium having an information recording track as a groove and pre-format information as phase pits, wherein the phase pit of interest for the groove of interest has the same groove depth as the groove groove depth . The attention
Light that is formed in a shape partition wall is generated in the radial direction between the Rutotomoni the target groove connected radially to the Heidelberg Le <br/> over blanking be adjacent to the target phase pit side of the groove Information recording medium. 2. The optical information recording medium according to claim 1, wherein the radial width Δ of the partition wall and the track pitch TP satisfy the relationship Δ / TP ≧ 0.1. 3. The width Wp of the phase pit, the length Lp in the circumferential direction thereof, the track pitch TP, and the spot diameter BD of the recording / reproducing beam are Lp / BD <1.0 0.8 ≦ Wp / TP ≦ The optical information recording medium according to claim 1, wherein the relationship of 0.9 is satisfied. 4. The width Wp of the phase pit, the length Lp in the circumferential direction thereof, the track pitch TP, and the spot diameter BD of the recording / reproducing beam are 1.0 ≦ Lp / BD 0.5 ≦ Wp / TP ≦ The optical information recording medium according to claim 1, wherein the relationship of 0.8 is satisfied. 5. The width Wp of the phase pit, the length Lp in the circumferential direction thereof, the track pitch TP, and the spot diameter BD of the recording / reproducing beam are 1.0 ≦ Lp / BD 0.8 ≦ Wp / TP ≦ The optical information recording medium according to claim 1, wherein the relationship of 0.9 is satisfied. 6. A method for mastering a groove and a phase pit in the optical information recording medium according to claim 1, wherein the mastering has two grooves for the groove and the phase pit. , The spot diameter of the exposure beam for the groove is BD1, the spot diameter of the exposure beam for the phase pit is BD2, the spot interval between these two exposure beams is L, and the radial width of the partition wall is Δ. , Δ = L- (BD1 / 2)-(BD2 /
2) A mastering method for an optical information recording medium, which satisfies the following relationship. 7. The spot interval L1 is fixed by changing the size of the spot diameters BD1 and BD2, and the incident angle of one of the two exposure beams with respect to the objective lens is changed by an optical deflecting element. 7. The method for mastering an optical information recording medium according to claim 6, wherein the adjustment is performed.