JPS63228721A - Manufacture of gap single crystal wafer - Google Patents

Abstract

PURPOSE:To obtain a wafer with high yield, by slicing an ingot of GaP signal crystal along the surface inclined at more than or equal to 3 deg. in the direction of <110> from a {100} plane, and performing a vertical slicing to an edge formed by the intersection of a {111} Ga face near the {100} plane and a {011} plane. CONSTITUTION:An ingot of GaP single crystal 4 is set on an equipment in the manner in which a surface 3 shifted a 3-10 deg. in the direction of [110] from a (100) plane of the wafer is obtained, and the feed direction of a slice blade 5 is perpendicular to an edge 6 formed by the intersection of a (111) Ga face near the (100) plane and a vertical (011) face. By feeding the blade 5 in assigned directions A and E, blade traces, chipping and cracks are remarkably decreased. An OF line 2 is formed on a (11-1)P face. A {100} plane equivalent to the (100) plane and a direction of <110> equivalent to [110] also can be used.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field)
It relates to the manufacturing method for P single crystal wafers, especially Ga
It is used in a method of slicing high-quality pieces from single-crystal ingots at a high yield.

(Prior art) Orange and yellow GaAsP light emitting diodes are manufactured using (1
00) Includes a step of epitaxially growing a GaASP layer on a GaP single crystal substrate having a low index plane by vapor phase growth. In this process, hillock (hi l 1oc)
In order to obtain an epitaxial surface with few surface defects such as small protrusions and pits, and with a well-controlled doping concentration, it is necessary to tilt the epitaxial surface slightly in the <110> direction from the (100) low index plane. It is preferable to use a planar substrate, and generally planar substrates displaced from the (100) plane by 3° to 10° in the <100> direction are manufactured.

As a method for manufacturing a substrate having such a displacement plane as a main surface, there is a method of slicing a single crystal ingot along the displacement plane. However, when slicing along the displacement plane, saw marks (marks of the slicing blade), chipping, and cracks are more likely to occur than when slicing along the (100) low index plane, and the surface The quality and yield were highly variable and unstable. (100
) The larger the displacement from the surface, the more likely it is that saw marks, chipping,
The eagle grows bigger.

(Problems to be Solved by the Invention) As mentioned above, in the production of GaASP light emitting diodes, (
100) It is preferable to use a displacement plane slightly inclined from the low index plane as a planar substrate, but slicing along the displacement plane makes the surface quality and yield unstable.

-3 It is possible to slice thickly along the low-index plane (100) that is easy to slice, and then finish the desired displacement plane by angle polishing on both sides, but this may result in more grinding losses or complicate the process. There are drawbacks.

The present invention provides a method for manufacturing GaP single crystal wafers that can stably suppress the occurrence of saw marks, chipping, cracks, etc. during displacement plane slicing, which are the problems of the prior art, and can obtain high quality wafers at a high yield. The purpose is to

[Structure 1 of the invention (Means for solving the problems and their effects) The present invention has the following features:
When slicing a GaP single crystal ingot to obtain a wafer whose slice plane is a displacement plane tilted by at least 3° in the (100) direction, the wafer is sliced along the displacement plane and the above ( A GaP single crystal wafer characterized in that it is sliced by sending a slicing blade in a direction perpendicular to the ridge where the (111) Ga plane adjacent to the (100) plane intersects with the (ON) plane perpendicular to the (100) plane. This is a manufacturing method.

By slicing in the slicing blade feeding direction of the present invention, saw marks that occur when slicing in other directions,
The occurrence of chipping and cracking is suppressed, and the same surface quality and slicing yield as in the case of slicing the (100) plane can be ensured.

In this specification, planes and orientations within a crystal are expressed using (for example, <100) plane and [100] orientation.
) and [1 are used. Also, use () and 〉 for a set of equivalent planes and a set of equivalent orientations, respectively. For example, in a cubic crystal, (100).

(010), (001), (TOO), (
0+0).

Each plane of (OOT) is completely equivalent, and a set of such equivalent planes is expressed as {100} of (. write down

(Example) The present invention will be described in detail with reference to FIGS. 1 to 3. The head and tail of a GaP single crystal ingot with a diameter of 52 ± 1 + nm and a length of 120111 m were pulled and grown in the [100] direction by the pulling method, and the head and tail portions were removed by end face cutting. A cylindrical rod with a length of 100 mm was obtained by grinding the outer periphery. diameter 50
After finishing within ±0.5 mm, an orientation flat 2 with a length of 12+nm was placed on the (011) plane adjacent to the (111) 2 plane.

FIG. 1(a) is a schematic front view showing the relationship between the slicing blade feeding direction and the slicing surface (displacement surface) 3 in the manufacturing method of the present invention, and FIG. 1(b) is a plan view thereof.

Figure 2 shows a device based on the (100) plane of a GaP single crystal. In order to obtain a plane displaced by 10° from the (100} plane of GaP single crystal ingot 4 in the [101] direction, the displaced plane 3 was made parallel to the cutting surface of the inner peripheral blade. That is, Fig. 1 (a
), and the feeding direction of the rotating inner circumferential cutter 5 is arranged between the (111) Ga plane and the (100) plane, which are close to the (100) plane.
00) plane perpendicular to the (011) plane intersects with the edge 6 (see Fig. 2), that is, Fig. 1(b)
Set the GaP single crystal ingot in the slicing device as shown below. Next, a 300 Ltm thick wafer was sliced from the GaP single crystal pulling head side according to predetermined operations. In other words, feed the slicing blade in the direction shown in Figure 2.
When 150 pieces were sliced, only 3 pieces had poor thickness, resulting in a yield of 98%.

Next, the slices were sliced in the directions of arrows S to H in Figure 2 using the same procedure to obtain the results shown in Table 1.

As is clear from Table 1, in order to slice a GaP single crystal and obtain a slice plane displaced by 10° from the (10(1)) direction to the <100> direction, the (111) Ga plane and (011)
) plane, that is, the direction perpendicular to the edge where the plane intersects A
It can be seen that by sending the slicing blade in the E direction and slicing, saw marks, chipping, and cracks are significantly reduced, and the slicing yield is significantly improved.

Table 1 (Relationship between slicing direction and yield) In the above example, the GaP single crystal ingot pulling direction [10
The (100) plane perpendicular to [0] was used as a reference, and the displacement plane was tilted 10'' in the [101] direction.

If this <100> plane is used as a reference, [101], [+1
0], [ITO] An exciting displacement surface (slicing surface) with an inclination of 10' and an inclination of 10' is obtained, and in this case, the feeding direction of the slicing blade is close to the <100) plane (+11 )
Ga plane, (1'i-d>Ga plane and (011) plane, (0
11) Direction perpendicular to the edges where the planes intersect, that is, the second
The direction is A or E in the figure, and these actions and effects are equivalent to those of the previous embodiment. Also, a plane equivalent to the (100) plane may be used as the reference plane.

In addition, in this example, the seeds were pulled up and grown in the 1001 direction (of
100} Although the case of slicing a crystal from the head side has been described, the situation is exactly the same when slicing from the crystal tail side, and although a high slicing yield was obtained by the present invention, the feeding direction of the slicing blade is It must be noted that the direction is 90° different from the direction in which the slice is sliced from the side.

In the above embodiment, an example of displacement with an inclination of 10° was described, but 0 to
A shown in FIG. 2 for various displacements up to 106.

When sliced from three directions B and C, the results shown in FIG. 3 were obtained. That is, it can be seen that the effect of the present invention is particularly remarkable when the displacement angle is 3° or more.

Note that the present invention is not limited to GaP single crystals, but also applies to other GaA
It can also be applied to ■-v group single crystals such as S and InP.

[Effects of the Invention] As described above, according to the method for manufacturing a GaP single crystal wafer of the present invention, the generation of saw marks, chipping, and cracks in the conventional slicing process can be stably suppressed, and the slicing yield can be significantly increased. This has great industrial effects, as high-quality wafers can be stably obtained at the same time.

[Brief explanation of drawings]

Fig. 1 is a layout diagram showing the positional relationship between the slicing blade, its feeding direction, and the displacement plane of the single crystal ingot in the manufacturing method of the present invention; Fig. 2 is a schematic diagram showing the plane device for GaP single crystal; The figure is a diagram showing the effects of the present invention. 1... (100) plane, 2... Orientation flat, 3... Unusual elevation, 4... Single crystal ingot, 5... Slice blade, 6... Intersecting edges. (a) Figure 1

Claims (1)

[Claims] 1 <11 from {100} plane of GaP single crystal ingot
0> Slice along a displacement plane tilted by at least 3° in the direction and {111} close to the {100} plane above.
} A method for manufacturing a GaP single crystal wafer, characterized in that slicing is carried out by sending a slicing blade in a direction perpendicular to an edge where the Ga plane and the {011} plane perpendicular to the {100} plane intersect.