GB2309582A - Method and apparatus for manufacturing a semiconductor device with a nitride layer - Google Patents
Method and apparatus for manufacturing a semiconductor device with a nitride layer Download PDFInfo
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- GB2309582A GB2309582A GB9613672A GB9613672A GB2309582A GB 2309582 A GB2309582 A GB 2309582A GB 9613672 A GB9613672 A GB 9613672A GB 9613672 A GB9613672 A GB 9613672A GB 2309582 A GB2309582 A GB 2309582A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
- H01L21/02227—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process
- H01L21/02252—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process formation by plasma treatment, e.g. plasma oxidation of the substrate
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
- H01L21/02227—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process
- H01L21/02247—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process formation by nitridation, e.g. nitridation of the substrate
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/028—Coatings ; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers
- H01S5/0281—Coatings made of semiconductor materials
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/0201—Separation of the wafer into individual elements, e.g. by dicing, cleaving, etching or directly during growth
- H01S5/0203—Etching
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/028—Coatings ; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers
- H01S5/0282—Passivation layers or treatments
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/16—Window-type lasers, i.e. with a region of non-absorbing material between the active region and the reflecting surface
- H01S5/164—Window-type lasers, i.e. with a region of non-absorbing material between the active region and the reflecting surface with window regions comprising semiconductor material with a wider bandgap than the active layer
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Description
2309582 - 1 METHOD AND APPARATUS FOR MANUFACTURING A SEMICONDUCTOR DEVICE
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for manufacturing a semiconductor device, particularly a semiconductor laser.
Compound semiconductor devices such as a semiconductor laser and a hetero-junction bipolar transistor are manufactured through a complicated process in which a multi-layer crystal structure serving as an active layer is epitaxially grown on a semiconductor substrate and thereafter this crystal structure is treated or processed into a desired shape. Oxidation of the treated surface in the process provides a number of surface levels, thus deteriorating the device characteristic.
For example, in the process of manufacturing a high is power laser of an A1GaAs family, a laser oscillation end face is normally formed by cleavage in air. This process provides surface potential in the oscillation end face, thus causing typical failure mode such as end face breakage which will be described below.
In the high power laser of an A1GaAs family, the presence of a surface potential in the oscillation end face equivalently decreases the band gap in the neighborhood of the end face relatively to the central portion of laser.
- 1 2 Therefore, the region in the neighborhood of the end face serves as a light absorption region for the wavelength of laser light so that an increase in an optical power output increases local heat production in the above absorption. The band gap further decreases with a rise in temperature. This provides a positive feedback of a further increased absorption in laser light and temperature rise, thus eventually leading to melting breakage. Such a phenomenon is referred to as optical damage (COD) which is a serious problem in the high power laser of an A1GaAs family. The laser having an end face window structure for restricting the optical damage has been proposed.
Fig. 5 is a perspective view showing one example of the conventional end face window structure laser. The conventional end face window structure laser is disclosed in e.g. K. Sasaki et al, Japanese Journal of Applied Physics Vol. 30, No. 5B, pp. L904-L906 (May, 1991). The conventional end face window structure laser is manufactured as follows. First, a crystal structure of laser is formed on a p-GaAs substrate 21 by an ordinary manufacturing process, and the crystal structure is cleaved in a bar state to form a cleavage end face 27 serving as a resonator end face. Thereafter, an A1GaAs layer 28 that is an window layer is grown on the cleavage end face 27. After the provision of electrodes, the structure is separated into individual laser chips.
In recent years, attempts of treating the laser end face have been actively carried out by a technique of dry etching. Further, as an attempt of suppressing oxidation of the treated surface, a "total manufacturing process" in which dry etching and epitaxial growth are carried out without touching air has been developed. For example, Fig. 6 shows the conventional total manufacturing process apparatus as disclosed in a reference: Technical Report of IEICE (The Institute of Electronics, Information and Communication Engineers), ED94-85, CPM94-81 (November, 1994). In the figure, reference numerals 7 and 8 denote an ECR etching chamber and a MOCVD chamber, respectively. In this is apparatus, the ECR etching chamber 7 and the MOCVD chamber 8 are coupled with each other through a vacuum tunnel so that after micro- treating, wafers can be transferred to the MOM chamber 8. Where this apparatus is applied to fabrication of a window structure laser, the oscillation structure end face of a laser is formed by ECR etching and subsequently a crystal layer serving as a window is formed in the MOCVD chamber 8. In this case, since the treated surface is not exposed to air, production of a surface level can be suppressed, thus enabling an improved window-structure semiconductor laser to be manufactured.
4 Figs. 7A to 7C show a method of making a sample of the window structure semiconductor laser using the total manufacturing process. First, an insulating film 32 formed on an epitaxial wafer 31 in a laser structure composed of GaAs and A1GaAs is patterned (Fig. 7A). The epitaxial wafer 31 is etched using the insulating film 32 as a mask in the ECR etching chamber (Fig. 7B). After it is transferred to the MOCVD chamber 8, an A1GaAs layer 33 is re-grown on the wafer 31. Evaluation results of the sample made by the above conventional total manufacturing process is shown in Fig. 8. In the graph of Fig. 8, the ordinate indicates a ridge width and the abscissa indicates the threshold current of a laser. Dotted lines indicate calculated values when the interface recombination speed at a re-growth boundary is estimated at 100 m/sec, 1000 m/sec and 2000 m/s and 10000 m/sec, respectively. Solid line indicate values measured in the present experiment. Generally, as regards the material of A1GaAs series, the interface recombination speed in the multi-layer structure continuously grown by e.g. MOCVD is 10 m/sec or less. However, the presence of an interface level or accumulated impurities at the interface in the multi-layer structure increases the interface recombination speed. As seen from Fig. 8, the interface recombination speed at the regrowth interface in the present experiment was 1000 - 2000 m/sec.
- 5 Since the conventional end face window structure is structured as described above, a complicated process is required in which after the crystal structure of laser is once cleaved in a bar state, the end face window layer is formed. This process is much more inferior in massproductivity than the ordinary semiconductor process in which the manufacturing process is performed thoroughly in a wafer state until the provision of electrodes. In addition, since the end face is formed by cleavage, the cleavage end face is oxidized immediately to form a surface level. For this reason, the subsequent provision of a window layer cannot give a sufficient window effect. Further, the method of treating the laser end face by dry etching, which forms the surface level owing to treating damage, oxidation after is treating, etc. cannot also solve the problem of failure due to optical damage.
The conventional total manufacturing process apparatus disclosed in the above reference: Technical Report of IEICE, ED94-85, CPM94-81 may suppress oxidation of the treated surface. But, since the value of the interface recombination speed of 1000 - 2000 m/sec in Fig.8 is approximately equal to that of the sample obtained commonly by wet etching and MOCVD re-growth in air, it cannot be admitted that the total manufacturing process could improve the interface quality. This suggests a problem that in the is conventional total manufacturing precess, in which after the etching, the wafer is transferred in vacuum and the MOCVD re growth without touching air is carried out, a large amount of impurities are left at the interface. Further, as disclosed in e.g. Technical Report of IEICE, ED94-22, CPM94-23(May, 1994) or Journal of Crystal Growth (146 (1995)527), the most serious problem in the total manufacturing process is presence of oxygen. Since the MOCVD chamber, into which large amounts of high purity oxygen is always supplied, contains very small amounts of left air, it can be supposed that in the above total manufacturing process, the wafer is contaminated within the ECR etching chamber or the vacuum tunnel.
SUMMARY OF THE INVENTION
The present invention has been accomplished in order to solve the above problem, and provides a method and apparatus of manufacturing a semiconductor device which can realize a clean treated interface in the process of successively performing ECR plasma etching and MOCVD growth, and a method of manufacturing a semiconductor laser which can suppress optical damage by realizing a clean treated interface, and has great reliability and reduce production cost.
The method of manufacturing a semiconductor device according to the present invention comprises: a first step of 6 - micro-treating the surface of a semiconductor substrate,' on which a semiconductor layer, an insulating layer, etc. are formed, in a vacuum chamber by plasma etching; and a second step of irradiating the surface of a semiconductor substrate -5 after said micro-treating with nitrogen plasma in the same vacuum chamber as in the first step, thereby forming a nitride film on said micro-treated surface.
The method of manufacturing a semiconductor device according to the present invention also comprises the steps of: a first step of microtreating the surface of a semiconductor substrate, on which a semiconductor layer, an insulating layer, etc. are formed, in a vacuum chamber by plasma etching; a second step of irradiating the surface of a semiconductor substrate after said micro-treating with nitrogen plasma in the same vacuum chamber as in the first step, thereby forming a nitride film on said micro-treated surface; and a third step of carrying out the crystal growth of a semiconductor layer on the semiconductor substrate with said nitride film thus formed.
The crystal growth is carried out by MOCVD.
The substrate transfer between the second and third steps is performed in an atmosphere of hydrogen or inert gas with high cleanliness.
The plasma etching uses ECR plasma etching.
8 The apparatus of manufacturing a semiconductor device according to the present invention comprises: a plasma etching chamber in which plasma processing is performed for a substrate located in an vacuum atmosphere and into which etching gas and nitrogen gas can be introduced; a crystal growth chamber in which semiconductor crystal is grown on the substrate located in a vacuum atmosphere; and a transfer chamber coupled with said plasma etching chamber and said crystal growth chamber, in which said substrate is transferred in an atmosphere of hydrogen or inert gas with high cleanliness.
Said plasma etching chamber is an ECR plasma etching chamber and said crystal growth chamber is an MOCVD chamber.
The method of manufacturing a semiconductor laser comprises the steps of: forming an insulating film on an epitaxial wafer having a semiconductor laser structure; patterning said insulating film so as to open an region serving as an laser oscillation end face; forming said laser oscillation end face by ECR plasma etching using the patterned insulating film as a mask; and irradiating the laser oscillating end face with nitrogen plasma in the same chamber as said ECR plasma etching is performed, thereby forming a nitride layer on the wafer surface with said laser oscillation end surface formed thereon.
- 9 The method of manufacturing a semiconductor laser according to the present invention comprises the steps of: forming an insulating film on an epitaxial wafer having a semiconductor laser structure; patterning said insulating -5 film so as to open an region to be an laser oscillation end surface; forming said laser oscillation end surface by ECR plasma etching using the patterned insulating film as a mask; irradiating the laser oscillating end surface with nitrogen plasma in the same chamber as said ECR plasma etching is performed, thereby forming a nitride layer on the wafer face with said laser oscillation end face formed thereon; and forming a semiconductor layer on said laser oscillation end face with said nitride layer thereon, said semiconductor layer having a band gap that is larger than the oscillating wavelength of laser on the laser oscillation end face.
The substrate transfer between the step of forming a nitride film and the step of forming a semiconductor layer is performed in an atmosphere of hydrogen or inert gas with high cleanliness.
BRIEF DESCRIPTION OF THE DRAWINGS
Figs. 1A to 1C are views showing a process for manufacturing a semiconductor laser according to the first embodiment of the present invention; Figs. 2A to 2D are views showing a process for manufacturing a laser-structure epitaxial wafer of the - 10 semiconductor laser according to the first and the second embodiment of the present invention; Figs. 3A to 3D are views showing a process for manufacturing a semiconductor laser according to the second embodiment of the present invention; Fig. 4 is a schematic view showing a total manufacturing process according to the third embodiment of the present invention; Fig. 5 is a perspective view showing one example of a conventional end face structure semiconductor laser; Fig. 6 is a schematic view showing a conventional total manufacturing process apparatus; Figs. 7A to 7C are views showing a process for manufacturing a sample manufactured by the conventional total is manufacturing precess apparatus; and Fig. 8 is a view for explaining problems of the conventional total manufacturing process.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Embodiment 1
Figs. 1A to 1C are views showing a process of manufacturing a semiconductor laser according to Embodiment 1 of the present invention. The process is illustrated in the form of a part of an epitaxial wafer, i. e. only a single chip cut way from the wafer (The actual process is carried out in a state of wafer and the wafer is cut into individual chips after the process is completed).
In the figure, reference numeral 1 denotes an epitaxial wafer having a laser structure; 2 an SiON film that is an insulating film; 3 an opening for pattering; and 4 an surface nitride layer. Figs. 2A to 2D show a process of making the epitaxial wafer 1 having a laser structure. This example is directed to a high power laser for exciting a fiber amplifier in a band of 0.98 gm. First, by MOCVD, on an n-GaAs substrate 11 are successively crystal-grown an n A10.48Gao-52As layer 12, an active (TQW) layer 13, a p A10.48Gao-52As layer 14, a p-Alo.6_5Gao.3_,,As(ESL) 15, another p A10.48Gao---52As layer 14 and a p-GaAs layer 16, thus making an A1GaAs multi-layer structure (Fig. 2A). By selective etching using as a mask an SiN film 17 formed on the p-GaAs layer 16, a ridge (optical waveguide) is formed (Fig. 2B). Again, by MOCVD, an n-A10.7Gao.3As current blocking layer 18 and a p-GaAs layer 19 are formed (Fig. 2C). After the SiN film 17 is removed, by MOCVD, a p-GaAs contact layer 20 is formed, thus completing the laser-structure epitaxial wafer 1 (Fig. 2D) An explanation will be given of the process of manufacturing a semiconductor laser according to this embodiment of the present invention. First, on the laser structure epitaxial structure wafer 1, an SiON film 2 that is an insulating film is formed by e.g. plasma CVD, and the 12 - wafer 1 is so patterned that the several parts of the SiON film 2 constituting oscillation end faces of laser are opened (Fig. 1A). The patterned wafer is etched by ECR plasma etching to form oscillation end faces of laser (Fig. 1B). The etching was carried out using a C12/N2 mixed gas under the condition of gas flow rate C12 = 3.0 sccm, N2 = 7.0 sccm, gas pressure of 0.4 mTorr, microwave power of 200 W, RF power of 10 W, main magnetic field current of 15A, auxiliary magnetic field current of 10A and substrate temperature of 50 'C. Under this condition, the etching speed of 1200 A/min was obtained for GaAs. Gas species of only N2 were introduced to generate nitrogen plasma, thereby nitriding the treated oscillation end face to form a surface nitride layer 4 (Fig. 1C). This treatment partially substitutes the is A1Ga(As)N/Ga(As)N layer that is the surface nitride layer 4 for the treated end face, i.e., the section of the A1GaAs/GaAs multi-layer structure. The reason of expression of (As) is that the surface subjected to ECR etching is rich in III group elements so that the surface nitrided by nitrogen plasma is considered to have become almost an A1GaN/GaN layer. The depth of the surface nitride layer 4 is estimated at about 20 A, and the band gap is estimated at about 2.5 eV.
The A1Ga(As)N/Ga(As)N layer which is the surface nitride layer 4 passed the above step is very stable so that 13 - it very efficiently serves to suppress the adsorption of residual oxygen in a chamber and a transfer chamber. This A1Ga(As)N/Ga(As)N layer, which will not greatly oxidized unlike normal A1GaAs even when exposed to air, serves as a surface protection film.
After the above steps, the SiON film 2 is removed and a p-electrode and nelectrode are formed. Thereafter, end face coating and chip separation are effected to complete chips of a semiconductor laser. The above surface nitride layer 4 serves as an oxidation protection film during the wafer processing.
As described above, in accordance with this embodiment, the etched surface of the A1GaAs/GaAs multi-layer structure having undergone ECR etching was subjected to nitrogen plasma treatment to form the surface nitride film 4. The surface nitride film 4 serves as a surface protection film which can suppress oxidation of the etched surface. This permits contamination of the treated surface to be controlled precisely so as to suppress a surface level from being formed, thereby completing a very reliable semiconductor laser.
is Embodiment 2 Figs. 3A to 3D are views showing a process for manufacturing an end face window semiconductor laser which is Embodiment 2 of the present invention. The process is 1 - 14 illustrated in the form of a part of an epitaxial wafer, i.e.
only a single chip cut from the wafer (The actual process is carried out in a state of wafer and the wafer is cut into individual chips after the process is completed). Figs. 3A to 3C are the same as Figs. 1A to 1C in connection with Embodiment 1. This embodiment also, as in Embodiment 1, uses the laser-structure epitaxial wafer 1 formed by the manufacturing process as shown in Figs. 2A to 2D. This embodiment is characterized in that the wafer with a surface nitride film 4 formed as in Embodiment 1 is transferred, in an atmosphere of hydrogen with high cleanliness, to the MOCVD chamber coupled with the ECR etching chamber, and within the MOCVD chamber, an A1GaAs window layer 5 is further on the laser oscillation end face (Fig. 3D). The end face window structure semiconductor laser according to this embodiment is manufactured by the total manufacturing process that will be described in connection with Embodiment 3. The total manufacturing process apparatus includes an ECR plasma etching chamber and a MOCVD chamber coupled with each other, in which substrate transfer is carried out in an atmosphere of hydrogen with high cleanliness.
As described in connection with Embodiment 1, the surface nitride layer 4 serves as a surface protection film.
The surface nitride layer 4 has a band gap of about 2.5 eV 2-5 which is larger than the energy 1.26 eV corresponding to 980 - run which is an oscillation wavelength of the present laser so that the nitride film itself serves as an end window layer. But, in order to suppress optical damage more surely, the thickness of the end face widow layer is desired to be 1000 3000 A or so. For this reason, in this embodiment, the surface nitride layer 4 is used as a protection film for suppressing oxidation by residual oxygen when the wafer is transferred from the ECR plasma etching chamber to the MOCVD chamber, and thereaf ter an A10.5Gao., As layer having a thickness of 2000 A is caused to be grown on the surface nitride film 4 to manufacture the end face window-structure semiconductor laser having this A1GaAs layer 5 as a window layer.
In the end face window structure semiconductor laser thus manufactured, the end face is formed by ECR plasma etching, the protection layer of the surface nitride layer 4 is formed by nitrogen plasma, the wafer is transferred in an atmosphere of hydrogen with high cleanliness to the MOCVD chamber and thereafter the A1GaAs layer 5 is formed as a window layer. Thus, contamination of the treated surface can be suppressed to form an ideal window layer. The optical damage can be suppressed which is a main cause of deterioration of current passage, thereby improving reliability of the laser. The manufacturing process can be greatly simplified as compared with the conventional end face - 16 window structure laser. This is very advantageous in reduction of the manufacturing cost. In this embodiment, although the wafer transfer was carried out in an atmosphere of hydrogen with high cleanliness, inert gas may be used in place of hydrogen to obtain the same effect.
Embodiment 3 Fig. 4 is a view showing a semiconductor device manufacturing apparatus according to Embodiment 3 according to the present invention. The semiconductor device manufacturing apparatus according to this embodiment intends to manufacture a semiconductor device such as a semiconductor laser described in connection with Embodiment 2. In the figure, reference numeral 6 denotes a preparation chamber; 7 an ECR plasma etching chamber; 8 an MOCVD chamber; and 9 a wafer take-out chamber. These chambers are connected by a wafer transfer chamber 10. The apparatus according to this embodiment, in which the ECR plasma etching chamber 7 and the MOCVD chamber 8 are unified, is a total process apparatus which can continuously effect epitaxial growth without exposing the wafer surface to air after dry etching.
Now referring to Figs. 3 and 4, an explanation will be given of the procedure of manufacturing the end face window structure semiconductor laser according to Embodiment 2 using the present total manufacturing process apparatus.
The SiON insulating film 2 formed on the laser-structure 17 - epitaxial growth wafer 1 is patterned so as to open a portion constituting a laser oscillation end face. The wafer thus prepared is set in the preparation chamber 6. After the preparation chamber 6 and the wafer take-out chamber 9 are purged by hydrogen, the wafer is introduced into the ECR plasma etching chamber 7 via the wafer transfer chamber 10. The wafer transfer chamber 7 is supplied with hydrogen and is maintained at an atmospheric pressure. Although the ECR plasma chamber 7 is always maintained at high vacuum, only during the wafer transfer, it is purged by hydrogen and returned to atmospheric pressure. Thus, the wafer can be transferred in an atmosphere of hydrogen with high cleanliness at the atmospheric pressure. In this embodiment, although the hydrogen with high cleanliness was used, inert is gas may be used in place of hydrogen.
With The ECR plasma etching chamber 7 evacuated to process pressure (0.1 1 m Torr), the ECR plasma etching is performed and the nitriding treatment is subsequently performed to form a surface nitride layer 4 serving as a protection layer. In order to effect such a series of treatments, the ECR plasma etching chamber 7 is so adapted that it can take in an etching gas and N2 gas. Af ter the nitriding treatment, the ECR plasma etching chamber 7 is hydrogen-purged to return to atmospheric pressure. The wafer is introduced into the MOCVD chamber 8 through the wafer - 18 transfer chamber 10 to make re-growth of an A1GaAs layer 5 which is a window layer. Then, the growth pressure is 50 - Torr. After the MOCVD growth, the wafer is introduced into the wafer take-out chamber 9. The wafer after passed nitrogen-purging can be taken out.
The conventional total manufacturing process apparatus in which the wafer transfer chamber serves as a vacuum tunnel suffers from contamination of the wafer surface owing to slight residual oxygen. It is also difficult to maintain the environment of vacuum with high cleanliness. As a result, in many cases, the total process apparatus is scaled up to a large scheme. Particularly, such an apparatus can not be actually applied to massproduction process. In this embodiment, the wafer transfer is effected in an atmosphere of hydrogen with high cleanliness at an atmospheric pressure so that contamination of the wafer can be suppressed. Further, after etching, since the surface stabilizing treatment by nitrogen plasma can be carried out, a very clean re-grown surface can be obtained, thus providing a reliable semiconductor device.
- 19
Claims (12)
1. A method of manufacturing a semiconductor device comprising the steps of:
micro-treating a surface of a semiconductor substrate, on which a semiconductor layer and an insulating layer are formed, in a vacuum chamber by plasma etching; and irradiating the surface of a semiconductor substrate after said micro- treating with nitrogen plasma in the vacuum chamber to form a nitride film on said micro-treated surface.
2. A method of manufacturing a semiconductor device as claimed in claim 1, further comprising a step of making a crystal-growth of a semiconductor layer on the semiconductor substrate with said nitride film thus formed.
3. A method of manufacturing a semiconductor is device as claimed in claim 2, wherein the crystal growth is carried out by MOCVD.
4. A method of manufacturing a semiconductor device as claimed in claim 2, wherein the semiconductor substrate is transferred between the step of forming the nitride film and the step of crystal growth in an atmosphere of one of hydrogen and clean inert gas with high cleanliness.
5. A method of manufacturing a semiconductor device as claimed in claim 1, wherein the plasma etching is ECR plasma etching.
6. An apparatus for manufacturing a semiconductor device comprising:
a plasma etching chamber in which plasma treatment is performed for a substrate located in an vacuum atmosphere and into which etching gas and nitrogen gas can be introduced; a crystal growth chamber in which semiconductor crystal is grown on the substrate located in a vacuum atmosphere; and a transfer chamber coupled with said plasma etching chamber and said crystal growth chamber, in which said substrate is transferred in an atmosphere of hydrogen or is inert gas with high cleanliness.
7. An apparatus of manufacturing semiconductor as claimed in claim 6, wherein said plasma etching chamber is an ECR plasma etching chamber and said crystal growth chamber is an MOCVD chamber.
8. A method of manufacturing a semiconductor laser comprising the steps of:
forming an insulating film on an epitaxial wafer having a semiconductor laser structure; patterning said insulating film so as to open an region to be an laser oscillation end face; forming said laser oscillation end face by ECR plasma etching using the patterned insulating film as a mask; and irradiating the laser oscillating end face with nitrogen plasma in the same chamber as said ECR plasma etching is performed to form a nitride layer on the wafer surface with said laser oscillation end face formed thereon.
9. A method of manufacturing a semiconductor laser as claimed in claim 8, further comprising a step of forming a semiconductor layer on said laser oscillation end surface with said nitride layer thereon, said semiconductor layer having a band gap that is larger than the oscillating wavelength of laser on the laser oscillation end face.
10. A method of manufacturing a semiconductor device as claimed in claim 9, wherein the semiconductor substrate is transferred between the step of forming the nitride film and the step of forming the semiconductor layer in an atmosphere of one of hydrogen and clean inert gas with high cleanliness.
-2211. A method of manufacturing a semiconductor device substantially as described hereinbefore with reference to and as shown in figures 1, 2 or 3 of the accompanying drawings.
12. An apparatus constructed, adapted and arranged to perform substantially as described hereinbefore with reference to and as shown in figure 4 of the accompanying drawings.
12. An apparatus constructed, adapted and arranged to perform substantially as described hereinbefore with reference to and as shown in figure 4 of the accompanying drawings.
Amendments to the claims have been filed as follows 9-3 CLAIMS 1. A method of manufacturing a semiconductor device comprising the steps of: micro-treating a surface of a semiconductor substrate, on which a semiconductor layer and an insulating layer are formed, in a vacuum chamber by plasma etching; and irradiating the surface of a semiconductor substrate after said micro-treating with nitrogen plasma in the same vacuum chamber to form a nitride film on said microtreated surface without exposing it to air.
2. A method of manufacturing a semiconductor device as claimed in claim 1, further comprising a step of making a crystal-growth of a semiconductor layer on the semiconductor substrate with said nitride film thus formed.
3. A method of manufacturing a semiconductor device as claimed in claim 2, wherein the crystal growth is carried out by MOCVD.
4. A method of manufacturing a semiconductor device as claimed in claim 2, wherein the semiconductor substrate is transferred between the step of forming the nitride film and the step of crystal growth in an atmosphere of one of hydrogen and clean inert gas with high cleanliness.
2-Mr 5. A method of manufacturing a semiconductor device as claimed in claim 1, wherein the plasma etching is ECR plasma etching.
6. An apparatus for manufacturing a semiconductor device comprising:
a plasma etching chamber in which plasma treatment is performed for a substrate located in an vacuum atmosphere and into which etching gas and nitrogen gas can be introduced; a crystal growth chamber in which semiconductor crystal is grown on the substrate located in a vacuum atmosphere; and a transfer chamber coupled with said plasma etching chamber and said crystal growth chamber, in which said substrate is transferred in an atmosphere of hydrogen or inert gas with high cleanliness.
7. An apparatus of manufacturing semiconductor as claimed in claim 6, wherein said plasma etching chamber is an ECR plasma etching chamber and said crystal growth chamber is an MOCVD chamber.
8. A method of manufacturing a semiconductor laser comprising the steps of:
Z5 forming an insulating film on an epitaxial wafer having a semiconductor laser structure; patterning said insulating film so as to open an region to be an laser oscillation end face; forming said laser oscillation end face by ECR plasma etching using the patterned insulating film as a mask; and irradiating the laser oscillating end face with nitrogen plasma in the same chamber as said ECR plasma etching is performed to form a nitride layer on the wafer surface with said laser oscillation end face formed thereon.
9. A method of manufacturing a semiconductor laser as claimed in claim 8, further comprising a step of forming a semiconductor layer on said laser oscillation end surface with said nitride layer thereon, said semiconductor layer is having a band gap that is larger than the oscillating wavelength of laser on the laser oscillation end face.
10. A method of manufacturing a semiconductor device as claimed in claim 9, wherein the semiconductor substrate is transferred between the step of forming the nitride film and the step of forming the semiconductor layer in an atmosphere of one of hydrogen and clean inert gas with high cleanliness.
2 (c 11. A method of manufacturing a semiconductor device substantially as described hereinbefore with reference to and as shown in figures 1, 2 or 3 of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8012325A JPH09205254A (en) | 1996-01-26 | 1996-01-26 | Manufacture of semiconductor device, semiconductor manufacturing device, and method for manufacturing semiconductor laser |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9613672D0 GB9613672D0 (en) | 1996-08-28 |
| GB2309582A true GB2309582A (en) | 1997-07-30 |
Family
ID=11802169
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9613672A Withdrawn GB2309582A (en) | 1996-01-26 | 1996-06-28 | Method and apparatus for manufacturing a semiconductor device with a nitride layer |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPH09205254A (en) |
| DE (1) | DE19631132A1 (en) |
| GB (1) | GB2309582A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6821806B1 (en) | 1998-09-11 | 2004-11-23 | Sharp Kabushiki Kaisha | Method for forming compound semiconductor layer and compound semiconductor apparatus |
| US8198179B2 (en) | 2007-02-21 | 2012-06-12 | Showa Denko K.K. | Method for producing group III nitride semiconductor light-emitting device |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6123414B2 (en) * | 2013-03-27 | 2017-05-10 | 三菱電機株式会社 | Semiconductor element manufacturing method and semiconductor element manufacturing apparatus |
| JP6265032B2 (en) * | 2014-04-28 | 2018-01-24 | 住友電気工業株式会社 | Semiconductor photo detector |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0448763A1 (en) * | 1990-03-30 | 1991-10-02 | Siemens Aktiengesellschaft | Process and apparatus for manufacturing conductive layers or structures for highly integrated circuits |
| EP0450255A1 (en) * | 1990-04-06 | 1991-10-09 | International Business Machines Corporation | Process for forming the ridge structure of a self-aligned semiconductor laser |
| US5336361A (en) * | 1990-03-23 | 1994-08-09 | Matsushita Electric Industrial Co., Ltd. | Method of manufacturing an MIS-type semiconductor device |
| US5376223A (en) * | 1992-01-09 | 1994-12-27 | Varian Associates, Inc. | Plasma etch process |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3886751T2 (en) * | 1988-09-12 | 1994-06-23 | Ibm | Method for etching mirror facets on III-V semiconductor structures. |
| US5144634A (en) * | 1989-09-07 | 1992-09-01 | International Business Machines Corporation | Method for mirror passivation of semiconductor laser diodes |
| US5354698A (en) * | 1993-07-19 | 1994-10-11 | Micron Technology, Inc. | Hydrogen reduction method for removing contaminants in a semiconductor ion implantation process |
-
1996
- 1996-01-26 JP JP8012325A patent/JPH09205254A/en active Pending
- 1996-06-28 GB GB9613672A patent/GB2309582A/en not_active Withdrawn
- 1996-08-01 DE DE19631132A patent/DE19631132A1/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5336361A (en) * | 1990-03-23 | 1994-08-09 | Matsushita Electric Industrial Co., Ltd. | Method of manufacturing an MIS-type semiconductor device |
| EP0448763A1 (en) * | 1990-03-30 | 1991-10-02 | Siemens Aktiengesellschaft | Process and apparatus for manufacturing conductive layers or structures for highly integrated circuits |
| EP0450255A1 (en) * | 1990-04-06 | 1991-10-09 | International Business Machines Corporation | Process for forming the ridge structure of a self-aligned semiconductor laser |
| US5376223A (en) * | 1992-01-09 | 1994-12-27 | Varian Associates, Inc. | Plasma etch process |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6821806B1 (en) | 1998-09-11 | 2004-11-23 | Sharp Kabushiki Kaisha | Method for forming compound semiconductor layer and compound semiconductor apparatus |
| US8198179B2 (en) | 2007-02-21 | 2012-06-12 | Showa Denko K.K. | Method for producing group III nitride semiconductor light-emitting device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09205254A (en) | 1997-08-05 |
| GB9613672D0 (en) | 1996-08-28 |
| DE19631132A1 (en) | 1997-07-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |