JP2005142391A - Optical semiconductor device and its producing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical semiconductor device and its producing process in which production yield can be enhanced by suppressing cracking of a substrate in the production process without deteriorating the characteristics. <P>SOLUTION: The optical semiconductor device comprises an optical semiconductor element having an element region on a compound semiconductor substrate wherein an angle of 5-85° is set between the dicing direction of the optical semiconductor element and the orientation of cleavage surface of the compound semiconductor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical semiconductor device using a compound semiconductor substrate and a manufacturing method thereof.

  In general, an optical semiconductor element (chip) used in an optical semiconductor device such as an LED is formed by forming an element region on a compound semiconductor substrate and dicing it (see, for example, Patent Document 1).

At this time, dicing is usually performed along the crystal orientation of the compound semiconductor substrate. For example, as shown in FIG. 8, after an element region is formed on the surface of the GaP substrate 11 (100), it is patterned in a lattice shape so as to be parallel (0 degree) / 90 degrees with the (100) orientation flat 16 ( The dicing pattern 17) is 1st dicing (half dicing) from the element region side. Then, after mesa etching, 2nd dicing is performed from the substrate side, and after mesa etching, the chips are separated.
Japanese Patent Laid-Open No. 2002-231994

  However, after the first dicing, there is a problem that the substrate is broken even though the substrate is not separated. Although the cause of such a problem can be attributed to each process and handling between processes, it has been difficult to suppress this particularly during mass production.

  Therefore, the present invention aims to provide an optical semiconductor device and a method of manufacturing the same that can eliminate the conventional problems and suppress the cracking of the substrate in the manufacturing process and improve the yield without deteriorating the characteristics. It is what.

  According to one aspect of the present invention, an optical semiconductor element having an element region formed on a compound semiconductor substrate is provided, and an angle between a dicing direction of the optical semiconductor element and a fracture interface direction of the compound semiconductor is 5 to 5 An optical semiconductor device characterized in that the angle is 85 degrees is provided.

  According to another aspect of the present invention, the predetermined dicing pattern is formed so that the angle between the step of forming the element region on the compound semiconductor substrate and the fracture interface of the compound semiconductor is 5 to 85 degrees. And a method of forming an optical semiconductor element by dicing the compound semiconductor substrate with the dicing pattern.

  According to one embodiment of the present invention, it is possible to provide an optical semiconductor device and a method for manufacturing the same that can suppress the cracking of the substrate in the manufacturing process and improve the yield without degrading the characteristics.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view of an optical semiconductor element in the optical semiconductor device of this embodiment, and FIG. 2 is a top view. As shown in the figure, an element region 2 is formed on a GaP substrate 1, and n-side and p-side electrode portions 3 and 4 are formed on each surface. A (100) plane ((010) plane) 5 which is a fracture interface (peel interface) of the GaP substrate is in the diagonal direction of the element.

  Such an optical semiconductor element is formed as follows. As shown in FIG. 3, an element region is formed on the (100) surface of the GaP substrate 1 on which the (100) orientation flat 6 is formed, and one axis is 45 degrees with the orientation flat by a normal PEP (Photo Etching Process). Then, the dicing pattern 7 is formed in a lattice shape.

  Next, as shown in FIG. 4, electrode portions 3 and 4 having a predetermined pattern are formed on the p side and the n side by vapor deposition and lift processes, and then the dicing blade 8 extends from the formation surface side of the element region 2 to the GaP substrate 1. 1st dicing and mesa etching are performed. At this time, a significant difference in the etching shape and the etching rate was not recognized as compared with the pattern having a parallel (0 degree) / 90 degree pattern with the conventional orientation flat.

  Further, as shown in FIG. 5, 2nd dicing and mesa etching are performed from the substrate side to separate the respective optical semiconductor elements. At the time of 2nd dicing, compared with what was diced by the conventional cracking interface, although a cross section has an unevenness | corrugation, it becomes flat similarly to the past by mesa etching.

  In this way, an optical semiconductor element diced at 45 degrees with the orientation flat of the GaP substrate is formed, and an optical semiconductor device is configured through processes such as mounting and bonding.

  When the life evaluation was performed by energizing the optical semiconductor device thus formed and measuring the time when the optical output was 70%, no significant difference was observed with respect to the conventional optical semiconductor element, and the application of a constant current was confirmed. No significant difference was found in the output voltage (DC characteristics) due to. Also, no significant difference was observed in the optical characteristics.

  On the other hand, Table 1 shows the results of strength evaluation (simple flexural strength evaluation) after 1st dicing. Evaluation is performed according to the following flow.

1) The substrate 1 (about 230 μm thick) on which the dicing pattern is formed is fixed so that the center portion of the substrate is positioned on the end surface of the inspection table. At this time, the table end surface 8 is parallel (A) or 45 degrees (B) with the orientation flat 6 as shown in FIG.

2) Apply a weight of 2-3mm from the periphery of the substrate with a gauge.

尚、ここで、切り込み量とは、基板表面より１ｓｔダイシングにより切り込まれた深さを示す。 3) Apply weight gradually and read the tension (gauge value) at the time of breakage

Here, the cut amount indicates the depth cut by the first dicing from the substrate surface.

  At this time, the crack directionality has a strong correlation with the dicing pattern line, and it is found that the crack directionality is extremely weak against the stress in the 90 degree direction in the conventional patterning in the 90 degree direction. On the other hand, it can be seen that the dicing pattern formed at 45 degrees has higher cracking strength than the conventional pattern.

  In the optical semiconductor device thus formed, the crack strength is improved, so that the crack loss after the first dicing is reduced, and the yield can be improved.

(Embodiment 2)
In the present embodiment, although it is almost the same as in the first embodiment, the dicing pattern 7 ′ is not formed in the direction of 45 degrees, and one axis has an angle of 60 degrees with the orientation flat 6 as shown in FIG. Is different in that.

  Also in the present embodiment, an optical semiconductor device is formed as in the first embodiment, and similarly, the crack loss after the 1st dicing is reduced, and the yield can be improved.

In these embodiments, a GaP substrate is used as the compound semiconductor substrate, but the present invention is not limited to this, and a compound semiconductor substrate such as a GaAs substrate, a LiAlO ₂ substrate, or a sapphire substrate can be used. Further, in the GaP substrate, the cracking interface (peeling interface) is the (100) plane, but the plane orientation differs depending on these crystal systems, and each has only to have a predetermined angle with the cracking interface.

  In this case, it is necessary to have an angle of 5 to 85 degrees. If it is less than 5 degrees or exceeds 85 degrees, the angle with the cracking interface is small, so if stress is applied after 1st dicing, it will cleave at the cracking interface. More preferably, it is 30 to 60 degrees.

In the optical semiconductor element formed in these embodiments, the shape itself is not different from the conventional one, but the fracture surface is formed by a destructive test (for example, intensive stress is applied to the central portion to cause destruction). However, it is possible to find a difference by forming it at a predetermined angle (5 to 85 degrees) with respect to the dicing direction of the element.
In addition, this invention is not limited to embodiment mentioned above. Various other modifications can be made without departing from the scope of the invention.

1 is a cross-sectional view of an optical semiconductor element in one embodiment of the present invention. 1 is a top view of an optical semiconductor element in one embodiment of the present invention. FIG. 6 illustrates a dicing pattern of a semiconductor element according to one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor element in one embodiment of the present invention. 4A and 4B illustrate a manufacturing process of a semiconductor element in one embodiment of the present invention. 10A and 10B illustrate a method for evaluating a semiconductor element according to one embodiment of the present invention. FIG. 6 illustrates a dicing pattern of a semiconductor element according to one embodiment of the present invention. The figure which shows the dicing pattern of the conventional semiconductor element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11 GaP board | substrate 2 Element area | region 3 N side electrode part 4 P side electrode part 5 Cracking interface 6, 16 Orientation flat 7, 17 Dicing pattern 8 Inspection table end surface

Claims (5)

Comprising an optical semiconductor element having an element region formed on a compound semiconductor substrate;
An optical semiconductor device, wherein an angle between a dicing direction of the optical semiconductor element and a cracking interface direction of the compound semiconductor is 5 to 85 degrees.   The optical semiconductor device according to claim 1, wherein the angle is 30 to 60 degrees.   The optical semiconductor device according to claim 1, wherein the compound semiconductor substrate is a GaP substrate. Forming an element region on the compound semiconductor substrate;
Forming a predetermined dicing pattern so that an angle with the cracked interface of the compound semiconductor is 5 to 85 degrees;
A method of manufacturing an optical semiconductor device, comprising: a step of dicing the compound semiconductor substrate with the dicing pattern to form an optical semiconductor element.   The method of manufacturing an optical semiconductor device according to claim 4, wherein the angle is 30 to 60 degrees.

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