JPS6058690A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To maintain the reliability of the manufacturing process by confirmation of the result of quality judgement at the time of characteristic inspection on the basis of signs by a method wherein signs indicating the apearance of semiconductor elements are marked on the surface of the semiconductor element. CONSTITUTION:An InPn single crystal ingot 1 is sliced into a wafer 2 to be processed, the wafer 2 being severed and contained in a liquid epitaxial device, and rectangular wafers 4 being then produced. Next, each wafer 4 is subjected to growing treatment and treatments such as partial diffusion and electrode formation, resulting in the formation of a plurality of semiconductor element regions 5 in n colums and m lines. At this time, an address 6 consisting of the colum number 7 and the line number 8 of the wafer 4 is marked in each region 5. Then, a semiconductor laser element 9 is formed by separation of the wafer 4 at the boundary of the regions 5 so that the end surface of a resonator may become a mirror surface. The result of quality judgement at the time of characteristic inspection is confirmed on the basis of the address 6, and accordingly the reliability of the manufacturing process for the semiconductor device is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a semiconductor device and a method for manufacturing the same, and particularly to a technique that is effective when applied to a semiconductor device manufacturing technique that emits atoms from an end face of a semiconductor element.

[Background technology]

Semiconductor laser devices are widely used as light emitting sources for audio discs, video discs, optical communications, and the like.

A semiconductor laser element (chip) that emits a laser beam and is incorporated into a semiconductor laser device is described, for example, in Nikkei Electronics Magazine, September 14, 1981, pages 138-151.
"Semiconductor laser that meets the demands of audio discs"
As described in the above, since the structure is such that laser light is emitted from the end face of the chip, it is not possible to test the characteristics of the chip in the state of the wafer on which the chip is manufactured. For this reason, when testing the characteristics, the wafer is cut into strips and the output surface (end of the common camera) from which the laser emits light is emitted at regular intervals on both sides is exposed, either as a strip or as a chip. I am doing it. Furthermore, screening to eliminate defective products and early failure products prior to shipment is, of course, performed on the chip.

However, in the above-mentioned inspection state, inspection information such as characteristic inspection and screening is performed on strips of wafers or individual chips, so the distribution and correlation of defective products on the wafer cannot be determined. failure analysis,
The inventors of the present invention clearly pointed out that a problem arises in that it is difficult to take effective measures to improve the characteristics.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device and a method for manufacturing the same, in which failure analysis and defect removal measures are easy to take.

The above and other objects and novel features of the present invention are as follows:
It will be clear from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

That is, in the manufacture of semiconductor laser devices, before the wafer is divided into semiconductor laser devices, the address of each unit block on the wafer is indicated on the surface of the unit block that will become each semiconductor laser device on the wafer. ,
As a result, even if the characteristics are measured and screened in the state where the semiconductor laser elements are separated into semiconductor laser elements, it is possible to easily confirm which position on the wafer each semiconductor laser element was placed in by checking the address, and the confirmation results can be checked. By being able to provide feedback to semiconductor device manufacturing, it is possible to manufacture semiconductor devices with high reliability and high yield.

〔Example〕

FIGS. 1 to 1E are a perspective view, a plan view, and a cross-sectional view showing an outline of a method for manufacturing a semiconductor laser device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a method for manufacturing a BH (buried heterostructure) type semiconductor laser device. In this example, InGaAsP/In
A method for manufacturing a P-based long wavelength semiconductor laser will be described.

As shown in FIG. 1(a), an InP single crystal ingot 1 is first prepared, and then this single crystal ingot 1 is sliced to produce a processing wafer 2 having a thickness of several hundred μm.

In addition, before slicing the single crystal ingot 1, the orientation flat 3 is set so that the crystal plane direction can be confirmed.
Set it up.

Next, this processing wafer 2 is divided into rectangular wafers 4 that can be accommodated in a jig of a liquid phase epitaxial apparatus. In this example, from one processing wafer 2, A, B, O, D
Four wafers 4 are formed as shown in the figure (see BL).

Next, each wafer 4 is sequentially subjected to a liquid phase epitaxial growth process 9, partial diffusion, electrode formation, etc., to form semiconductor regions 5 in one column and m rows as shown in FIG. On this occasion,
An address 6 indicating its own position on the wafer 4 is displayed on the surface of each semiconductor element region 5. That is, address 6
is constituted by column number 7 at the upper left corner of semiconductor element region 5 and row number 8 at the lower right corner.

Next, the wafer 4 is divided at the boundary between each semiconductor element region 5, and semiconductor elements (chips) 9 are formed as shown in FIG.
form. The chip 9 is placed between the bones of the wafer 4 so that the end face of the resonator 10 becomes a mirror surface during analysis. Incidentally, column number 7 and row number 8 are formed by partially etching away the electrode 11 (area indicated by hatching in the figure) provided on the upper surface of the chip 9, as shown by dl in the figure.

Here, a method for manufacturing the buried heterostructure (BH) type chip 9 will be briefly described with reference to FIGS. 2(al) to (d).

First, the wafer 4 is prepared as shown in FIG. ' active layer 14.p-I
nP cladding layer 15. A multilayer growth layer 17 consisting of a cap layer 16 of p-1nGaAsP is provided, and a buffer layer 13. Activity/i14. A double heterojunction structure is formed by the rough cladding layer.

Next, as shown in FIG. 2B, a striped mask layer 18 is formed parallel to the main surface of the wafer 4 by conventional photolithography, and then etched to the middle of the buffer layer 13. An etching groove 19 is formed to reach the surface.

These etching grooves 19 extend in a direction perpendicular to a bone cut plane between the bones of the wafer 4 in chip formation to be described later. Note that the lower portion of the mask layer 18 remains in the shape of an inverted mesa, and the width of the active layer 4 is approximately several μm.

Next, after removing the mask M18, p-1nP blocking [120, n-InP cladding N21s
' Form a cap layer 37 of InGaAsP. Further, after partially forming the P3 edge film 22 on the lower surface of the wafer 4, the insulating film 22 is used as a mask to reach the middle of the cap layer 16 and the cladding layer 15 which is the lower layer of the cap layer 16. A Zn diffusion layer 23 in which Zn is diffused is formed ζf. In addition, the main surface and back surface (lower surface) of the wafer 4
Fluorescent electrodes 11.24 are formed on the VC. The electrode (upper electrode) 11 on the main surface has a structure in which it is divided on the central green of the cap layer 37, and when it is divided by scribing! , to prevent defective separation due to defective breakage of the pole 11. Note that this upper electrode 11 is formed by depositing an electrode material over the entire area of the evaporator, forming a mask layer made of photoresist on the electrode material, etching using the mask layer as a mask, and then removing the mask layer. It can be formed by nine.

Therefore, in this embodiment, an address pattern is provided in the photomask pattern when forming the mask layer, and the upper electrode 11 (for example, the lower layer is an Or
When forming a floating AU (with an upper layer of about 3000 A) by etching, address 6 consisting of column number 7 and row number 8 is formed on upper electrode 11 at the same time. At this time, column number 79 row number 8 is provided at a position off from above the resonator so that current flows uniformly to the electrode portion on the resonator and good laser oscillation occurs.

Next, after applying an external force with a knife or the like to one end of the wafer 4 and running interosseous lines at regular intervals along the interosseous surface of the crystal, the wafer 4 is scribed and cracked in a direction perpendicular to the interosseous lines. The strip is made into a strip, and the strip is broken at the interosseous line by cracking to form an H-shaped semiconductor laser element (chip) 9 as shown in the figure (dl).

Next, such a chip 9 is assembled into a package as shown in FIG. 1(e). That is, the package includes a disk-shaped copper stem 24 and a main surface of this stem 24 (
It consists of a metal cap 25 that is hermetically sealed on the upper surface. A heat sink 26 is provided on the main surface of the stem 24.
is fixed, and the chip 9 is fixed to the inner surface of the heat sink 26 via a submount 27. Lasers 5Y and 2B emit light from the upper and lower ends of the chip 9. The laser beam 28 emitted upward is transmitted to the transparent glass plate 2 airtightly attached to the opening of the cap 25.
It is emitted to the outside through a transparent window 30 formed by 9. Further, on the lower surface of the stem 24, there is a light receiving element 31 for monitoring the optical output of the laser beam 28 emitted downward.
is installed. Roughly speaking, a predetermined number of leads 32 are insulatively penetrated and fixed to the stem 24, and wires 33 connected to the electrodes of the light receiving element 31 and the semiconductor laser element 9 are connected to the inner ends of the leads 32. ing.

In manufacturing such a semiconductor laser device, the characteristics of the semiconductor laser element 9 are inspected, and only non-defective products are assembled into a package. Furthermore, after packaging, screening is performed to remove assembly-defective products and early failure products.

〔effect〕

(1) According to the present invention, it is possible to know the results of a characteristic test in a chip state or a strip state as to whether the product is good or defective as a position distribution on the wafer from the address displayed on the chip. Therefore, if the characteristic defects are closely related to the liquid phase epitaxial growth process used to form the multilayer growth layer of the wafer, it is necessary to know whether the liquid phase epitaxial growth process is performed uniformly over the entire wafer. It also serves as a guideline, and by modifying the liquid phase epitaxial growth conditions, changing the jigs, etc. used based on these failure analysis results, it is possible to improve the characteristics and improve reliability and yield based on the improved characteristics. can get.

(2) Similarly to (1) above, even in the case of characteristic defects caused by the Zn diffusion layer reaching the active layer, if the defect distribution on the wafer shows a certain tendency, liquid-phase epitaxial growth treatment can be applied similarly to the above effect. Modification of conditions.

It becomes possible to modify the Zn diffusion processing conditions, and the characteristics can be improved.

(3) Furthermore, as a result of aging and screening of the completed semiconductor laser device after packaging, it is possible to know the distribution trend of defective chips on the wafer by checking the addresses of the chips. can. As a result, defects caused by previous and previous processes can be known, and measures to reduce defects can be taken, and the occurrence of products with defective characteristics and early failures can be reduced, and yield and reliability can be improved.

(4) Since the column numbers and row numbers of the present invention are arranged symmetrically with respect to the center of the main surface of the depth, when one number is found, it is convenient to find the other number. effective.

(5) Due to (II to (3)) above, a synergistic effect can be obtained in that products of excellent quality can be manufactured at low cost due to improved yield and improved reliability.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, FIG. 3 shows an example in which more information is incorporated into the main surface of a semiconductor laser element (chip) 9, and the symbol indicating the origin of the chip 9 is 4XM class. . These symbols are shown with hatching in the same way as in the previous example.
It can be formed by partially etching away 1, and
It is provided at a position off from above the resonator lo. One of the symbols is column number 7 in the upper left corner of chip 9, as in the previous embodiment.
and wafer position number 34 in the processing wafer 2 at the lower left corner of the chip 9 [in this example, as shown in FIG. The wafer position number 34 indicates the wafer 4 at position A, since four wafers 4 are cut out from the wafer 2 labeled A to D.), and the manufacturing lot number (L3) shown at the lower right corner of the chip 9. 35. Processing wafer number 36 in single crystal ingot 1 shown at the center right of chip 9 (in this example, it is shown that processing wafer 2 is the sixth cut from the top of single crystal ingot 1) ).

In this embodiment, in addition to the effects of the previous embodiment, the crystal tendency in the axial direction and the plane direction perpendicular to the axis of the single crystal ingot 1, as well as the manufacturing tendency, etc., can cause defects in the chip 9 and its mounted products. It is also possible to analyze whether there is a deep correlation between the occurrence of the disease and the occurrence of the disease, and this information can be accurately fed back to the manufacturing system.

[Application field]

The above explanation has mainly been about the application of the invention made by the present inventor to the long-wavelength semiconductor laser device manufacturing technology, which is the background field of application, but the invention is not limited thereto. Manufacturing technology for semiconductor laser devices with various structures that emit light (including near-infrared light) and visible light, and edge-emitting light emitting diodes that emit light from the edge, as well as manufacturing other semiconductor devices using silicon substrates. The same applies to technology.

[Brief explanation of drawings]

FIG. 1 (al to tel are diagrams showing an outline of a method for manufacturing a semiconductor laser device according to an embodiment of the present invention, and FIG. 2(a) to
(dl is the same) A cross-sectional view showing a method for manufacturing a BH-type semiconductor laser device, and FIG. 3 is a plan view of a BH-type semiconductor laser device according to another embodiment of the present invention. 1... Single crystal ingot, 2 ...Wafer for processing, 3
...Orientation flat, 4...Wafer,
5... Semiconductor element area, 6... Address, 7... Column number, 8... Row number, 9... Semiconductor laser element (chip), 10... Resonator, 11... Electrode, 12...
Substrate, 13... Buffer layer, 14... Active layer, 15
...Clad layer, 16...Cap layer, 17...
Multilayer growth layer, 18... Mask 1. 19... Etching groove, 20... Blocking layer, 21... Cladding layer, 22... Insulating film, 23... Zn diffusion layer, 24...
... Stem, 25... Cap, 26... Heat sink, 27... Submount, 28... Laser light,
29...Transparent glass plate, 30...Transparent window, 31...
・Photodetector, 32...Lead, 33...Wire 3
4...Wafer position number, 35...Manufacturing lot number,
36... Wafer number for processing, 37... Cap layer. Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A semiconductor device characterized in that a symbol indicating the origin of the semiconductor element is displayed on the main surface of the semiconductor element. 2. The above symbol is the address of the semiconductor element on the wafer. 2. The semiconductor device according to claim 1, wherein a part or all of a manufacturing lot number is displayed on a single crystal ingot and a semiconductor device manufacturing lot number. 3. The semiconductor device according to claim 1, wherein the semiconductor element is a semiconductor laser element that emits light from an edge surface or a T-diode that emits light from an edge surface. 4. A method for manufacturing a semiconductor device comprising the steps of dividing a wafer into semiconductor elements, and inspecting the characteristics of the divided semiconductor elements, the method comprising: dividing a wafer into pieces into semiconductor elements; and testing the characteristics of the divided semiconductor elements. The method includes the step of providing a symbol indicating the origin of the single block region on the main surface of the single block region, and after the characteristic inspection step, the correlation between the characteristic inspection information and the origin of each semiconductor element is analyzed using the symbol. a step of determining manufacturing conditions for a semiconductor device manufacturing system.