JPH11274653A - Method for cleaving semiconductor laser substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the cleavage method of a semiconductor laser substrate, which has satisfactory productivity and has high yield at the time of cleaving and separating a semiconductor laser substrate. SOLUTION: In the cleavage method of a semiconductor laser substrate 1, the semiconductor laser substrate is cleaved and separated along a cleavage groove generated from a plurality of scribe scars 61, 62 ,..., 6n formed from one end 1a of the semiconductor laser substrate 1 containing an active layer 3 to the direction of the other end 1b, a plurality of semiconductor laser bars 7 are generated, the respective semiconductor laser bars 7 are divided into a plurality of bars in a direction different from that of the cleavage groove, and respective semiconductor layer elements 9 are formed. The scribe scars 61 , 62 ,..., 6n are sequentially formed in lengths l1 , l2 ,..., ln from a large one to a small one in a direction which is almost orthogonal to the active layer. Then, the semiconductor laser substrate 1 is sequentially cleaved in the direction of the scribe scars 61 , 62 ,..., 6n formed in the lengths l1 , l2 ,..., ln from the large one to the small one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaving a semiconductor laser substrate to produce a bar-shaped semiconductor laser and a semiconductor laser device.

[0002]

2. Description of the Related Art In order to manufacture a semiconductor laser device from a semiconductor laser substrate, it is necessary to cleave the semiconductor laser substrate into strip-shaped semiconductor laser bars. Both side surfaces of the semiconductor laser serve as resonator surfaces of the semiconductor laser element. Further, by dividing the semiconductor laser bar in a direction orthogonal to a predetermined width direction, a semiconductor laser device can be obtained. At this time, since the active layer of the semiconductor laser element is formed on the resonator surface side, both sides of the semiconductor laser must be damaged in order to obtain a semiconductor laser element having good characteristics. It is important to do without.

Hereinafter, a conventional method for cleaving a semiconductor laser substrate will be described with reference to FIGS. 3 to 7 are manufacturing process diagrams showing a method for cleaving a semiconductor laser substrate. In FIG. 4 and FIG. 5, the semiconductor laser substrate 1 and the cover sheet 8 are shown by dotted lines in order to easily explain the method of cleaving the semiconductor laser substrate.

First, the semiconductor laser substrate 1 shown in FIG. 3 will be described. As shown in FIG. 3, the semiconductor laser substrate 1 has electrodes 4 and 5 on both surfaces of a rectangular semiconductor laser crystal layer 2. On the electrode 5, a scribe flaw 1 having a length l ₀ and a depth d ₀ is provided at one end 2 a of the semiconductor laser crystal layer 2 in parallel with the cleavage direction of the semiconductor laser crystal layer 2.
1 _1, 11 _2, 11 ₃ are formed together a predetermined distance. Scribe scratches 11 ₁ , 11 ₂ , 11
Numeral ₃ is formed to facilitate cleavage of the semiconductor laser substrate 1. In addition, the scribe scratch 11 ₁ ,
11 ₂ and 11 ₃ are formed by a point scriber (not shown) so as to mechanically reach the vicinity of the surface of the semiconductor laser crystal layer 2 from above the electrode 5. Usually, the formation of the scribe scratches 11 ₁ , 11 ₂ , 11 _{3 on} the semiconductor laser substrate 1
This is performed from above the electrode 5 so as to reduce the impact from a point scriber (not shown) to the semiconductor laser crystal layer 2.
The interval between the scribed scratches 11 ₁ , 11 ₂ , and 11 ₃ is a resonator length of a semiconductor laser element described later, and is about 250 μm. An active layer 3 is formed in the vicinity of the electrode 4 of the semiconductor laser substrate 1, and the active layer 3 is formed of a semiconductor laser.
It is formed in a direction substantially perpendicular to the cleavage direction of the crystal layer 2.
That is, the active layer 3 has scribed scratches 11 ₁ , 11 ₂ , 1
It is formed on a ₃ substantially perpendicular direction.

Next, a semiconductor laser substrate cleaving apparatus 21 used for cleaving the semiconductor laser substrate 1 will be described with reference to FIG. Semiconductor laser substrate cleavage device 2
1 is a holder 15 having an opening 15a, a holder-fixing base 16 having a storage part 16a for storing the holder 15, and a holder stored in the storage part 16a of the holder-fixing base 16. The holder 15 includes a holder 17 for pressing the holder 15 to the holder 16 and a screw 18 for fixing the holder 15 to the holder 16 together with the holder 17. Further, a cutter knife 19 for cleaving and separating the semiconductor laser substrate 1 is provided below the holder 15 fixed to the holder fixing base 16.
It is fixed to the fixture 20 and arranged. The cutter knife 19 has a band-shaped blade longer than the shape of the semiconductor laser substrate 1 and can operate up, down, left and right.

[0006] The semiconductor laser substrate cleavage device 2 will be described below.
The method for cleaving the semiconductor laser substrate 1 will be described with reference to FIG. (Attaching semiconductor laser substrate) Electrode 5 having scribed flaws 11 ₁ , 11 ₂ and 11 ₃ formed on semiconductor laser substrate 1
The semiconductor laser substrate 1 is attached to the adhesive sheet 13 with the side facing upward and the electrode 4 side facing the adhesive sheet 13.
Further, a cover sheet 14 slightly smaller than the adhesive sheet 13 is placed on the semiconductor laser substrate 1 and the adhesive sheet 13 so as to cover the semiconductor laser substrate 1 (FIG. 4).

(Fixing of the adhesive sheet)
The holder 15 is placed on the adhesive sheet 13 from above the cover sheet 14 so that the semiconductor laser substrate 1 is accommodated in the opening 15a of FIG. 5 (FIG. 5). At this time, the shape of the holder 15 is substantially equal to the size of the adhesive sheet 13 and is fixed by the adhesive portion 12 of the adhesive sheet 13. As a result, the holder 15 is attached to the cover sheet 1.
4. It is integrated with the semiconductor laser substrate 1 and the adhesive sheet 13.

(Holder fixed) This semiconductor laser substrate 1
Then, the integrated holder 15 is placed in the holder storage section 16a of the semiconductor laser substrate cleavage device 21. Next, the holder presser 17 is placed on the holder 15 and the holder-fixing base 16, and the holder presser 17 is placed on the holder-fixing base 1.
6, and the holder 15 is fixed to the holder-fixing base 16 (FIG. 6).

(Cleavage of Semiconductor Laser Substrate) Thereafter, a cutter knife 19 is arranged via an adhesive sheet 13 in parallel to the cleavage direction of the semiconductor laser substrate ₁ and opposed to the scribed scratch 111. From this state, the cutter knife 19
Semiconductor laser through the door 13 - - a The substrate 1 pushed up upwardly, starting from the scribing cracks 11 _1, along the cleavage groove V caused by the scribed lines 11 _1, the adhesive sheet by
The semiconductor laser substrate 1 is cleaved (FIG. 7). Thereafter, the cutter - a knife 19 adhesive sheet - via preparative 13, opposite arranged sequentially scribed lines 11 _2, 11 _3, in a similar manner, semiconductor laser - performing cleavage The substrate 1, semiconductor laser (not shown) −
Obtain Zaba. Thereafter, by dividing the semiconductor laser into a predetermined length in a direction substantially perpendicular to the cleavage direction of the semiconductor laser (not shown), a semiconductor laser element (not shown) is obtained. The reason why the cleavage of the semiconductor laser substrate 1 is performed sequentially from the end of the semiconductor laser substrate 1 is that the work of cleavage of the semiconductor laser substrate 1 can be performed mechanically, so that the production efficiency can be improved. Is high.

Here, the mechanism of cleavage separation of the semiconductor laser substrate 1 will be described. As shown in FIG. 7, when the semiconductor laser substrate 1 is pushed up by the cutter knife 19, the point of action of the force acting on the semiconductor laser substrate 1 is such that the adhesive sheet 13 has an adhesive sheet. 13 is a position C (operating point C) in contact with the cutter knife 19 through the cover 13, and on the side of the cover sheet 14, one end D (operating point D) of the semiconductor laser substrate 1 and the semiconductor laser substrate 1 Is the other end E (action point E). When the pushing-up force N ₁ acts on the semiconductor laser substrate 1, the reaction N ₂ and the semiconductor laser substrate 1 are applied from the cover sheet 14 to one end D of the semiconductor laser substrate 1.
A drag N ₃ acts on the other end E of the arm. From such a state,
The semiconductor laser substrate 1 is cleaved with the width d ₁ and the drag force N _{2 of one} of the separated portions 11 cleaved and separated from the semiconductor laser substrate 1 about the point of action C where the thrust N ₁ acts. model of forces consisting of the product - placement F ₁ and (N ₂ × d _1), a force consisting of the product of the width d ₂ and the drag N ₃ of the other unseparated portion 1 ₂ mode - instrument F ₂ (N ₃ × d ₂ ). As a result, semiconductor laser - separation portion 1 ₁ from The substrate 1 is separated, semiconductor laser (not shown) - Zaba - is the is obtained.

[0011]

However, the conventional method for cleaving the semiconductor laser substrate 1 has the following problems. When cleaving a The substrate 1, semiconductor laser - - semiconductor laser The substrate 1, cover - sheet - elastically deformed downward about the scribing cracks 11 ₁ by drag N _2, N ₃ from preparative 14.
For this reason, the drags N ₂ and N ₃ act on the entire surface of the semiconductor laser substrate 1 on the cover sheet 14 side. Semiconductor laser
Scribe scratches 11 ₁ , 11 ₂ , 1 formed on the substrate 1
Since 1 ₃ intervals are formed by 250μm about a minute space, it acts substantially equal to or slightly less degree of drag also scribed 11 ₂ adjacent to the scribed lines 11 _1. Cleavage of the semiconductor laser substrate 1 is caused by scribing 1
1 _1, 11 _2, 11 length of ₃ l ₀ is long, as the depth d ₀ is deep, it can be easily carried out, the scribed 1
The 1 _1, 11 _2, 11 ₃ of the variation in the length l ₀ and depth d ₀ is the condition and the electrode thickness of the point scriber (not shown), resulting in variation. For this reason, as shown in FIG.
If the length l ₀ and depth d ₀ of the scribed 11 ₂ is greater than the scribed 11 _1, semiconductor laser - The substrate 1
Is not from scribe scratch 11 ₁ but from scribe scratch 1
1 ₂ would be cleaved from. Semiconductor laser - after completion of the cleavage of The substrate 1 to the last, there is a need to re-cleaving the scribing cracks 11 ₁ again, had reduced the productivity.

The cleavage of the semiconductor laser substrate 1 is performed mechanically one after the other in the order of the scribed flaws 11 ₁ , 11 ₂ and 11 ₃ under predetermined conditions.
After pushing up the The substrate 1 portion, sequentially cutter - - the knife 19 to correspond to semiconductor laser - cutter ₁ scribed knife 19 11 _2, 11 ₃ to the corresponding semiconductor laser - The substrate 1
Go to part, semiconductor laser - for cleaving is carried out by pushing up the The substrate 1, the cutting knife 19, semiconductor laser already corresponds to the cleaved scribed 11 ₂ - thus pushing up the The substrate 1 portion.

[0013] semiconductor laser - The substrate 1 is, because it is cleaved already a separate detachable section 1 ₃ unseparated portion 1 _4, cutter - a knife 19 unseparated portions 1 ₄ and the separation portion 1 ₃
In between. At this time, semiconductor laser - a The substrate 1 separating portion 1 ₃ of the side P and unseparated portion 1 _fourth aspect Q
The adhesive sheet - via the door 13 cutter - so the impact of the force pushing up by the knife 19 will act, side Q side P and unseparated portion 1 ₄ separate portions 1 ₃ being damaged. Thus, the scribed grooves 11 of the isolation portion 1 _3
1 in correspondence, the separation portion 1 ₃ of the semiconductor laser is not cleaved shown performing - Zaba - be prepared, the separation portion 1
_Since the side surface P of No. ₃ was damaged, the yield of the semiconductor laser (not shown) was low. Also, the yield of semiconductor laser elements (not shown) obtained by dividing the semiconductor laser (not shown) was low. Further, since the side face P of the isolation portion 1 ₃ of the active layer 3 is formed, since the active layer 3 being damaged, this semiconductor laser - semiconductor lasers fabricated from The substrate - The element of Le - The The desired properties were not obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a high productivity and a high yield when cleaving and separating a semiconductor laser substrate. -To provide a method for cleaving the substrate.

[0015]

According to the method for cleaving a semiconductor laser substrate of the present invention, at least a semiconductor laser including an active layer is cleaved.
The semiconductor substrate is cleaved and separated along cleavage grooves generated from a plurality of scribed flaws formed at the edge of the substrate to produce a plurality of semiconductor lasers. A method for cleaving a semiconductor laser substrate that forms a plurality of semiconductor laser elements by dividing a plurality of semiconductor laser elements in different directions, wherein the scribe flaws are sequentially reduced from a large length to a small length in a direction substantially orthogonal to the active layer. And then sequentially cleave the semiconductor laser substrate in the direction of the scribe flaw formed from the larger to the smaller length.

According to a second aspect of the present invention, in the method for cleaving a semiconductor laser substrate according to the first aspect, the scribed flaws are sequentially formed in a direction from a large to a small size in a direction substantially orthogonal to the active layer, and The scribe flaws formed from this large to small length are periodically formed in the same direction, and toward the direction of the scribe flaws formed from this large to small length,
The semiconductor laser substrate is sequentially cleaved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for cleaving a semiconductor laser substrate according to the present invention will be described with reference to FIGS. FIG.
FIG. 3 is a diagram showing scribe flaws formed on the semiconductor laser substrate used in the first embodiment of the present invention. FIG. 2 is a view showing scribed flaws formed on a semiconductor laser substrate used in a second embodiment of the present invention. The same components as those in the related art are denoted by the same reference numerals, and detailed description thereof will be omitted.

A first embodiment of the method for cleaving a semiconductor laser substrate according to the present invention will be described below. First, a scribe flaw 6 _{1 is formed} on the electrode 5 of the semiconductor laser substrate 1 used in the conventional example.
6 _2, ..., semiconductor laser to 6 _n - along the cleavage direction of The crystal layer 2, and semiconductor laser - the other end 1 from one end 1a of The substrate 1
It is formed in the direction b, and the lengths l ₁ , l ₂ ,..., l _n corresponding thereto are formed from large to small (FIG. 1A). That is, l ₁ > l ₂ >>...> L _n . By the way, in general, the longer the length of the scribe flaw, the longer the cleavage groove becomes, so that the semiconductor laser substrate is easily cleaved. For this reason, the semiconductor laser - The on the substrate 1, semiconductor laser - scribed 6 ₁ in the order in which The substrate 1 is likely to be cleaved,
6 _2, ..., so that the 6 _n is formed. Incidentally, the scribed grooves 6 _1, 6 _2, ..., a length corresponding to each of the 6 _n l _1, l _2, ..., l _n is scribed lines 6 _1,
6 _2, ..., is set to produce a difference between the length negligible variation in the depth d of 6 _n.

Thereafter, in the same manner as in the conventional method for cleaving a semiconductor laser substrate, the conventional semiconductor laser shown in FIGS.
Using the substrate cleavage device 21, the cutter knife 19 is moved from one end 1 a to the other end 1 b of the semiconductor laser substrate 1.
The adhesive sheet - via preparative 13, arranged in correspondence with the scribed lines 6 _1, cutter - performs cleavage The substrate 1 - semiconductor laser from scribed 6 ₁ push up the knife 19 upwards.
Furthermore, the same manner as described above, the cutter - adhesive knife 19 - DOO 13 sequentially scribed 6 ₂ via, ..., arranged to correspond to 6 _n, semiconductor laser - performing cleavage THE substrate 1. Thus, a semiconductor laser 7 cleaved from the semiconductor laser substrate 1 is obtained (FIG. 1B). This semiconductor laser
The semiconductor laser element 9 is obtained by dividing the cover 7 in a direction substantially perpendicular to the cleavage direction (FIG. 1C).

As described above, by the conventional semiconductor laser substrate cleaving apparatus 21 shown in FIG. 7, the scribed flaws 6 ₁ , 6 ₂ formed in the direction from one end 1a to the other end 1b of the semiconductor laser substrate 1 are removed. Since the semiconductor laser substrate can be cleaved mechanically and sequentially from..., 6 _n , the productivity is improved. The semiconductor laser substrate 1 is provided with a cutter knife 19.
There scribed 6 _1, 6 ₂ corresponding, ..., since cleavage from only 6 _n is performed, the cutter - semiconductor knife 19 has already been cleaved separated les - pushing up the The substrate portion by the impact, semiconductor laser - Semiconductor laser separated from the substrate 1
Damage to the side surface 8 of the cover 7 can be prevented. For this reason, the yield of the semiconductor laser 7 and the semiconductor laser element 9 is improved.

Next, a second embodiment of the present invention will be described. The second embodiment of the present invention is effective when the shape of the semiconductor laser substrate is large. Scribing scratches 10 ₁ , 10 ₂ ,... Are formed on the electrodes 5 of the semiconductor laser substrate 1 used in the conventional example.
With 10 _n as one set, this set is formed periodically along the cleavage direction of the semiconductor laser crystal layer 2 and from one end 1a to the other end 1b of the semiconductor laser substrate 1 (FIG. 2). ). Scribed 10 _1, 10 _2, ..., a length corresponding to the respective 10 _n m _1, m _2, ..., m _n is, m _1> m
₂ >> ... _mn . Therefore, the scribe flaws 10 ₁ ,
10 _2, ..., 10 _n is the length _{m 1, m 2, ...,} m n is the set of small from large are periodically formed.

Thereafter, in the same manner as in the conventional method for cleaving a semiconductor laser substrate, the cutter knife 19 is attached with an adhesive sheet using the semiconductor laser substrate cleavage device 21 shown in FIGS.
Via the door 13, semiconductor laser - to face the scribed 10 ₁ end 1a of the The substrate 1, the cutter - a knife 19 Choke upward, semiconductor laser from scribed 10 ₁ -
The substrate 1 is cleaved. Further, in the same manner as described above, the first set of semiconductor laser substrates 1 is cleaved with the cutter knife 19 sequentially opposed to the scribed scratches 10 ₂ ,..., 10 _n via the adhesive sheet 13. . Next, the cutter blade 19 is sequentially opposed to the second set of scribed scratches 10 ₁ , 10 ₂ ,..., 10 _n via the adhesive sheet 13 to similarly cleave the semiconductor laser substrate 1. I do. Thus, similarly to the first embodiment, a semiconductor laser 7 cleaved from the semiconductor laser substrate 1 is obtained (FIG. 1B). The semiconductor laser 7 is divided in a direction substantially perpendicular to the cleavage direction of the semiconductor laser 7 to obtain a semiconductor laser element 9 (FIG. 1C).

In this case, when cleaving from the first set of scribe flaws 10 _n , the length m of the second set of scribe flaws 10 ₁ is m.
₁ is longer than the length m _n of the scribed grooves 10 _n,
It is cleaved from scribed lines 10 _1, scribing cracks 10 _n
But are not cleaved from, the scribed lines 10 _2, ...,
By adjusting the period of 10 _n to be short, the cleavage failure portion can be reduced. The cleavage defective portion, scribing cracks 10 _2, ... are the number order of the period of 10 _n,
The ratio of the entire semiconductor laser substrate 1 is very small, and the influence on the yield of the semiconductor laser 7 obtained from the semiconductor laser substrate 1 is very small. Therefore, the cleavage of the semiconductor laser substrate 1 can be performed mechanically in the order in which the scribed scratches 10 ₁ , 10 ₂ ,..., 10 _n are formed, so that the productivity of the semiconductor laser 7 is improved. I do.

[0024]

According to the method for cleaving a semiconductor laser substrate of the present invention, scribe flaws are sequentially formed on the semiconductor laser substrate in a direction substantially perpendicular to the active layer in a length from large to small. In addition, the semiconductor laser substrate can be cleaved and separated in the order in which the scribe flaws are formed, thereby improving the productivity.
In addition, since the scribed flaw of the semiconductor laser substrate once cleaved and separated is not re-cleaved, the semiconductor laser substrate can be cleaved without being damaged, so that the semiconductor laser substrate can be obtained from the semiconductor laser substrate. The yield of the semiconductor laser can be improved. Further, scribe flaws were sequentially formed in a direction from a large size to a small size in a direction substantially orthogonal to the active layer, and the scribe flaws formed in the size from a large size to a small size were periodically formed in the same direction. So, semiconductor laser
When the size of the substrate is large, defective portions having scribed flaws can be reduced, and the yield of semiconductor lasers can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a scribed flaw formed on a semiconductor laser substrate used in a first embodiment of the method for cleaving a semiconductor laser substrate of the present invention.

FIG. 2 is a perspective view showing scribed flaws formed on a semiconductor laser substrate used in a second embodiment of the method for cleaving a semiconductor laser substrate of the present invention.

FIG. 3 is a view showing a scribe flaw formed on a conventional semiconductor laser substrate.

FIG. 4 shows a conventional semiconductor laser attached to an adhesive sheet.
It is a top view of the substrate.

FIG. 5 is a plan view of a conventional semiconductor laser substrate processed together with an adhesive sheet into a holder.

FIG. 6 is a sectional view of a general semiconductor laser substrate cleavage apparatus.

FIG. 7 is a view showing a state of cleavage of a conventional semiconductor laser substrate using a general semiconductor laser substrate cleavage device.

FIG. 8 is a diagram illustrating a state of cleavage of a conventional semiconductor laser substrate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser board, 1a ... One end, 1b ... Other end, 2 ...
Semiconductor laser crystal layer, 3 ... active layer, 4, 5 ... electrode,
6 ₁ , 6 ₂ ,..., 6 _n , 10 ₁ , 10 _{2 ,.}
11 ₁ , 11 ₂ , 11 ₃ ... scribe flaw, 7 ... semiconductor laser, 8 ... side surface, 9 ... semiconductor laser element, 12 ... adhesive part, 13 ... adhesive sheet, 14 ... cover sheet G, 15 ...
Holder, 16: Holder fixing stand, 17: Holder holder, 18: Screw, 19: Cutter-knife, 20: Cutter-knife fixing tool, 21: Semiconductor laser substrate ₀ : Depth,
15a ... opening, 16a ... holder - containing portion, V ... cleavage groove ₁ 1, 1 ₃ ... separation part, 1 _2, 1 ₄ ... unseparated portion,
l ₁ , l ₂ , ..., l _n , m ₁ , m ₂ , ..., _mn ... length

Claims (2)

[Claims] At least one of a plurality of semiconductor lasers is formed by cleaving and separating along a cleavage groove formed from a plurality of scribed flaws formed at an end of a semiconductor laser substrate including an active layer. A method of cleaving a semiconductor laser substrate for forming each semiconductor laser element by dividing each semiconductor laser into a plurality of directions different from the cleavage groove direction, The semiconductor laser substrate is sequentially formed in a direction from the large to the small in a direction substantially orthogonal to the direction, and the semiconductor laser substrate is sequentially cleaved in the direction of the scribed flaw formed in the small to the large length. Cleaving method for a semiconductor laser substrate. 2. The method according to claim 1, wherein the scribe flaws are sequentially formed in a direction substantially perpendicular to the active layer in a length from large to small, and the scribe flaws formed in the length from large to small are periodically formed in the same direction. The semiconductor laser is formed in the direction of the scribed flaw formed to have a length from small to large.
2. The method for cleaving a semiconductor laser substrate according to claim 1, wherein the cleavage of the laser substrate is performed sequentially.