Fishing – trapping – and vermin destroying
Patent
1987-05-20
1989-01-10
Hearn, Brian E.
Fishing, trapping, and vermin destroying
148DIG29, 148DIG65, 148DIG72, 148DIG119, 156692, 437133, 437905, 437970, 357 16, H01L 2120, H01L 2176
Patent
active
047973749
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention concerns improvements in or relating to methods for producing a heterostructure electronic and optoelectronic devices in particular a device based upon indium phosphide substrate material.
Such devices as aforesaid include buried double heterostructure lasers, multiple quantum well lasers, heterojunction light emitting diodes and waveguide structures.
BACKGROUND ART
Hitherto, heterostructure devices have been produced by liquid phase epitaxy (LPE) and by metal-organic chemical vapour deposition (MOCVD) growth techniques. It has been conventional practice to produce these devices by defining structure in preformed multi-layer structures.
Typical processes as aforesaid comprise:
Process schedules for the above typically employ a large number of photolithographic mask definition stages and material selective etch process sequences. Furthermore, complex and expensive lithographic techniques are required for definition of sub-micron dimension structures.
DISCLOSURE OF THE INVENTION
The present invention is intended as a simple alternative technique to the foregoing.
It has now been discovered that the metal-organic chemical vapour deposition of group III-V materials is sensitive to the crystallographic orientation of the substrate material and the group V composition in the group III-V material. For example, it has been determined that selective deposition of such materials may be achieved by the use of arsenides, such as gallium indium arsenide or aluminium indium arsenide, whilst conformal deposition of these materials may be achieved by the use of phosphides, such as indium phosphide. It is thus now possible to define processing schedules that take advantage of orientation selective deposition.
The term III-V will not be described herein as it is considered to be a term understood by those skilled in the art.
In accordance with the present invention there is thus provided a method for producing a heterostructure semiconductor device, the method comprising defining a structure in a semiconductor substrate comprising a group III-V material, the structure comprising one or more first faces orientated parallel or near parallel to a first crystallographic plane and one or more second faces parallel or near parallel to a second crystallographic plane, and exposing the structure to a group III vapour phase chemical reagent group III or a group V chemical reagent or any admixture thereof, thereby to deposit a group III-V material on a first and/or a second face in dependence upon the group V constituent in the vapour phase chemical reagent or reagents.
The vapour-phase chemical reagents aforesaid may comprise either a mixture of metal-organic reagent species, or a mixture of metal-organic and hydride or halide reagent species.
The first faces may be oriented parallel or near parallel to the (100) crystallographic plane, and the adjacent second faces may be oriented parallel or near parallel to (111) A planes, to form mesa or trough structures. (The (111) A planes, referred to here, are group III atomic planes). It is often preferable to orientate said first faces at a slight offset of up to 5.degree., preferably 2.degree., relative to the (100) crystallographic plane, to provide a better key for deposition.
The aforesaid structure may be defined using an edge-aligned mask structure and an anisotropic etchant. For example, this may be performed using one or more oxide stripes aligned with edges extending in the (011) or (011) directions and a bromine based etchant, eg. an anisotropic etchant appropriate to the material being etched e.g. Bromine/Methonol (1%) solution, to reveal the (111) A plane faces in Indium Phosphide. Typically the mask stripes may be of between 3 and 6 microns in width and the mesas/troughs of between 2 and 3 microns in depth. At greater dimensions than these, the efficacy of this technique may depend upon size effects. However, the techinique has successfully been demonstrated using mesa/troughs of up to 100 .mu.m wide in recent studies.
BRIEF INTR
REFERENCES:
patent: 3425879 (1969-02-01), Shaw et al.
patent: 3586925 (1971-06-01), Collard
patent: 4066482 (1978-01-01), Shaw
patent: 4077817 (1978-03-01), Bellavance
patent: 4084130 (1978-04-01), Holton
patent: 4114257 (1978-09-01), Bellavance
patent: 4178197 (1979-12-01), Marinace
patent: 4467521 (1984-08-01), Spooner et al.
Oron et al., "Lasing Properties of InGaAsP Buried Heterojunction Lasers Grown on a Mesa Substrate", Appl. Phys. Lett., 41(7), Oct. 1982, pp. 609-611.
Kishino et al., "Fabrication . . . of Mesa Substrate Buried Heterostructure GaInAsP/InP Lasers . . . ," IEEE J. of Quantum Electronics, vol. QE-16, No. 2 Feb. 1980 pp. 160-164.
Sugimoto et al., "InGaAsP/InP Current Confinement Mesa Substrate Buried Heterostructure Laser Diode . . . ," IEEE J. Lightwave Tech. vol. LT-2, No. 4 Aug. 1984 pp. 496-503.
Ishikawa et al., "V-Grooved Substrate Buried Heterostructure InGaAsP/InP Laser", Electronics Letters, vol. 17, No. 13, Jun. 25, 1981, pp. 465-467.
Tamari et al., ". . . Crescent InGaAsP Mesa-Substrate Buried-Heterojunction Lasers", Electronics Letters, vol. 18, No. 4 Feb. 18, 1982 pp. 177-178.
Moore Alan H.
Scott Michael D.
Bunch William
Hearn Brian E.
Oglo Michael F.
Plessey Overseas Limited
Renfro Julian C.
LandOfFree
Method for selective heteroepitaxial III-V compound growth does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for selective heteroepitaxial III-V compound growth, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for selective heteroepitaxial III-V compound growth will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2107758