LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics最新文献

{"title":"High Performance 1.53 /spl mu/m InGaAsP/lnP Surface Emitting Distributed Feedback Laser Diodes With Monolithic Integrated Microlens","authors":"B. Stegmuller, H. Westermeier, W. Thulke, G. Franz, D. Sacher","doi":"10.1109/LEOSST.1991.639017","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.639017","url":null,"abstract":"","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"397 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123542474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication Of InGaAs/GaAs Quantum Well Demultiplexing Metal-semiconductor-metal (MSM) Photodetectors Using Selective Bandgap Tuning","authors":"A. Choudhury, P. Melman, A. Silletti, E. Koteles, B. Foley, B. Elman","doi":"10.1109/LEOSST.1991.639025","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.639025","url":null,"abstract":"Bandgap differences in adjacent absorbing sections are essential for demultiplexing and detection of different wavelengths in optical demultiplexers. This can be accomplished by applying one of various techniques, such as etch and regrowth, selective area epitaxy, impurity-induced disordering (IID) of quantum wells, and impurity-free vacancy diffusion (IFVD), to modify the shapes of quantum wells in the absorbing layer. In IFVD, vacancies are created and diffused to enhance intermixing of atoms at the quantum well interfaces, causing a bandgap energy shift that can be accomplished in either of two methods. One method relies on deposition of a silicon dioxide (or nitride) layer on a GaAs cap layer and promotes incorporation of Ga atoms in it at elevated temperature, creating Ga vacancies which then diffuse into the quantum well.1 A PIN photodetector has been demonstrated using this method., In the other method, a low energy ion implantation (i.e., As+) produces shallow damage on the GaAs cap layer by knocking out Ga atoms from their sites. The Ga vacancies thus created are diffused into the quantum well structure at high temperature.3 This method has better control of the continuous energy shift of the absorbing layer as a function of implant and annealing parameters4 than the first method and was applied in this work. A 5.5 nm wide 1n,,Gao.,As/GaAs strained layer quantum well structure, as shown in Figure 1, was used for device fabrication. The waveguide is defined by the AlGaAs cladding layers with a GaAs core layer on both sides of the quantum well. Part of the photodetector area was defined by photolithography and implanted with 35 keV, 2 x 1014 cm-2 As+ ions. Photoresist was removed in boiling acetone. The sample was then annealed capless in a rapid thermal annealing (RTA) system at 85OOC for 120 s. Room temperature photoluminescence (PL) showed a 30 nm (37 meV) shift in the absorption bandedge between the implanted and unimplanted regions. When oxygen (0,) plasma instead of acetone was used for photoresist removal prior to RTA, no such wavelength shift was observed. It is postulated that excess oxygen from 0, plasma on the GaAs surface forms strong bonds with the Ga vacancies and stops them from diffusing in during RTA. However, after RTA, the sample was treated in O2 plasma for a few minutes before Ti/Pt/Au Schottky fingers were deposited on the defined photodetector area. Figure 2 shows room temperature photocurrent response of the detectors illuminated from the top. The energy shift is dominated by heavy hole exciton peaks. The small peak around 910 nm corresponds to the light hole transition in the unimplanted detector. Figures 3 and 4 show the detector response for TE and TM modes, respectively. For this measurement, a fiber was butt-coupled at the front edge of the detector. It is clear from the figures that the detectors are polarization sensitive. The crosstalk for TE mode in the long wavelength detector (Figure 3) is due to insuffic","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"317 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132942859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication Of Circular Gratings On Lnp By E-beam Lithography And Reactive Ion Etching","authors":"M. Fallahi, C. Wu, C. Maritan, K. Fox, C. Blaauw","doi":"10.1109/LEOSST.1991.638990","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.638990","url":null,"abstract":"We demonstrate the possibility of fabricating second and first-order circular gratings on InGaAsPDnP waveguides by electron beam (E-beam) lithography of a single PMMA resist layer and two-step reactive ion etching (RE). Recently, there has been a growing interest in the study of circular grating resonators. Circular gratings have potential applications in low-divergence surface-emitting DFB lasers and in multi-port couplers[ 11. In spite of some theoretical works, it seems that no report on the fabriation of circular gratings on semiconductor materials has been published. This is probably due to the technical challenge in making circular gratings by conventioanl holographic techniques. The electron beam @-beam) lithography [2] offers high definition and reproducibility at small dimensions( nanometer grating lines), as well as flexibility in defining complex structures. We report here our results in fabricating first-order and second-order circular gratings on InP by E-beam writing and RIE etching. Our electron beam lithography system is a modified JEOL JSM-840A Scanning Electron Microscope (SEM). A commercial CAD package, DesignCAD, is used for the programmable pattern layout. A pattern generator driven by the CAD output package controls the electron beam of the SEM. The samples used in our experiment were grown by MOCVD on InP substrates. A double heterostructure planar waveguide was formed by the growth of a bottom cladding layer of InP (d =lo00 nm), followed by a guiding layer of InGaAsP ( hg =1.3 pm, d =170 nm) and a top cladding layer of InGaAsP (hg=1.0 pm, d= 200 nm). In the fabrication of circular gratings, a thin layer of Si02 (100nm) was deposited on the sample. Its purpose is to avoid erosion of the polymethyl methacrylate (PMMA) resist during the reactive ion etch (RE) process of InGaAsP. Then, a layer of PMMA resist of thickness 250 nm was spun on top of the sample and baked for 90 minutes at 165O C. Patterns of circular gratings were defined on the PMMA by using an electron beam exposure at 40 kev. The beam current was 150 pA and the line dose was 1.35 nc/cm. The resist was then developed in methyl isobutyl ketone (MIBK) at 21°C for 1 minute and rinsed in isopropanol. The circular gratings were then transferred into the Si02 layer by RIE, using CF4/H2, with the resist as a mask. After stripping the resist, the gratings were etched into the InGaAsP by R E using C W A r RE. Finally, the residual Si02 layer was removed. Figs.1-2 show the SEM photographs of a second-order circular grating and a secondorder+ first-order combination produced by the above techniques. The period of the second-order grating period is 0.398 pm and that of the first-order grating is 0.199 pm for an optical wavelength of 1.3 pmThe second grating has 350 circles while the combination","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127097572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RIBE And Sulfur-passivated For GaAiAs/GaAs BH Lasers","authors":"T. Tamanuki, F. Koyama, K. Iga","doi":"10.1109/LEOSST.1991.638939","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.638939","url":null,"abstract":"Micro-cavity surface emitting (SE) lasers(’) are becoming attractive for application to optoelectronics as well as lightwave communications. In order to realize micronor submicron-order cavity devices, the development of fine fabrication processes must be established. In this study, we have introduced an ammonium sulfide ((NH4)2Sr) treatment(2) into the MOCVD regrowth process, in order t o reduce the surface recombination on the side walls of a buried GaAs active region. Additionally, we discuss the active region size dependence of the threshold current in micro-cavity surface emitting (SE) lasers by taking the surface passivation into account. Also, we have introduced reactive ion beam etch (RIBE) to make micro-structures. First, we have applied the sulfur passivation to fabricate a buried heterostructure (BH) laser as shown in Fig. 1. The stri e widths are chosen to be 10 pm and 15 pm,respectively. We grew a standard DH structure witR active layer thickness of 0.5 pm. After forming a IO or 15 pm wide Si02 stripe mask, we chemically etched the sample to reach the the n-GaAlAs cladding layer with a H20:H202:H2S04 (8:8:1) solution at 20 “C to form mesas, and rinsed in deionized (DI) water. These samples were soaked in an (NHq)2Sz solution (sample “S-lo” and “S-15”) for about 8 hours, rinsed with DI water and were blown dry with N2 gas. The passivated samples were loaded into the MOCVD reactor and heated for 20 min at 630 “C. By this heat treatment the sulfur layer is believed to be completely removed, since the evaporation temperature of sulfur is 520 “ C (3) . After the current blocking layers were regrown and we formed the electrodes. The samples without ammonium sulfide treatment (sample “0-IO” and ‘c0-1577) were also fabricated for comparison. Tested samples were cleaved with 300 pm cavity length. We measured light output/current characteristics under pulsed condition at room temperature. In Table I we have summarized the accumulative data on the threshold current density and leakage current due to surface recombination. The stripe contact laser which does not have a BH structure is denoted as sample “St-15”. From Table I, the surface recombination velocity v, of the ( NH4)2SZ-passivated surfaces were reduced by one order in comparison with the non-passivated samples. Using these values, we can estimate the threshold current of micro cavity SE lasers. Figure 2 shows the dependence of threshold on active region diameter with the surface recombination velocity as a parameter. In case of v,=O, an ultra-low threshold current as low as 1 p A is possible when an active region can be D I pm as shown by the curve A(4). However, the ultimate threshold is limited to be 250 p A without the surface passivation (curve C). The threshold can be reduced by one order of magnitude as indicated by the curve B by using this passivation technique, compared with no passivation. Next, in an ultra high vacuum background Cl2-RIBE, we have found an isotropic etching co","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127547400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In-situ Processing Of GaAs/AiGaAs By Low Damage Selective Etching And Focussed Ion Beam Patterning","authors":"J. Skidmore, G. D. Spiers, J. English, Z. Xu, D. L. Green, D. Young, L. Coldren, E. Hu, P. Petroff","doi":"10.1109/LEOSST.1991.639006","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.639006","url":null,"abstract":"In-situ processing of III-V materials has attracted interest because of the capability to perform regrowth without having to expose surfaces to atmospheric or process-related contamination. However, the advantage of in-situ processing will not be fully realized until the following problems are addressed. First, a UHV dry etching process must be developed that has a high degree vertical and lateral resolution (to that obtained by MBE). Second, ion beams commonly used in etching processes are known to cause damage, and regrown material may be of poor quality even though the sample surface remains under vacuum. For these reasons, we use a dry etching process that combines a microwave excited chlorine radical beam with a low voltage argon ion beam (Radical Beam Ion Beam Etching (RBIBE)) which has been shown to provide smooth and highly chemically enhanced etching of GaAs [l]. We describe initial experiments performed in an integrated in-situ system incorporating RBIBE dry etching, MBE-regrowth and focused ion beam mOdifica tion. The in-situ processing system is shown in Fig. 1. The etching chamber (Fig. lb) is interconnected between two Varian Gen-II MBE's along a vacuum tunnel. A load-locked UHV shuttle/STM combination connects the tunnel to a Microbeam Inc. FIB system. As stated above, with RBIBE, independent control of the chemical component (Cl*) and physical component (Ar+) is achieved. This allows a detailed understanding of the role that chemical enhancement (etch rate) has on reducing damage from ion bombardment. We have performed electrical measurements of Schottky diodes (I-V and C-V) and cathodoluminescence from quantum wells near etched surfaces and found that RBIBE is lower in damage than ion beam assisted etching (where the chlorine is not \"cracked\") [2]. This is because in the case of RBIBE, to achieve the same etch depth, a smaller ion dose is needed. Also, a lower ion energy can be used. We are also using the etching chamber in conjunction with the FIB system for pattern transfer. Temkin et aZ.[3] has previously reported direct write-etching of InP by ion beam assisted etching of FIB-damaged substrates, but to our knowledge, it has not been reported in the GaAs/AlGaAs material system. A 50 keV focused Au+ beam was used to damage a GaAs/AlGaAs superlattice substrate to a dose of -1016/cm2. Afterwards, molecular chlorine etching was performed as shown schematically in Fig. 2. The damaged region is etched 1500 %r deep, far beyond the predicted implant range (400 A) and the surrounding undamaged etch depth i s only 150 %r giving a selectivity of 1O:l. Some of the selectivity may result from a thin native oxide on the surface which serves as a mask for the chemical etch, as well as from a higher etch rate of the damaged material. Further studies of direct write-etching -varying dose, ion energy, and ion species (Au and Si) -will elucidate this. The removal of implant damage by chemical etching is assessed by cathodolumhescence.","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125453955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design And Fabrication Of In-plane Ridge Waveguide Surface Emitting Lasers With Two Dry Etched 45/spl deg/ Total Reflection Mirrors","authors":"C. Chao, K. Law, J. Merz","doi":"10.1109/LEOSST.1991.639018","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.639018","url":null,"abstract":"In-plane surface emitting lasers (IPSELs) with 450 internal total reflection mirror(s) or external 4 5 O beam deflector@) may be used for optoelectronic integrated circuit (OEIC).1-3 In this work we describe a new ridge waveguide IPSEL (RW-IPSEL) structure with two 450 dry etched mirrors and an epitaxial grown distributed Bragg reflector (DBR). A 5pm wide device has continuous-wave (CW) threshold current at 1OmA which is a significant improvement among similar IPSELs.","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130146090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In-situ CI/sub 2/ Thermal Etching Of GaAs/AiGaAs For Damage Removal In A Plasma Etcher","authors":"J. Lechaton, P. Buchmann, H. Dietrich, G. Sasso, P. Vettiger, D. Webb","doi":"10.1109/LEOSST.1991.639007","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.639007","url":null,"abstract":"Energetically directed ions are necessary, in plasma processing, to achieve the anisotropic etching required for fabricating low loss and closely spaced micrometer structures in OEIC (e.g. lasers with etched mirrors [I], optical waveguides etc). However, plasma processes, by their very nature, cause surface and subsurface crystalline damage, resulting in high electron-hole ,recombination rates that degrade the device performance and reliability. Even at low ion energies (20 eV) the damage still extends to a depth of approximately 3 nm [2]. It was demonstrated [3] that GaAs can be chemically etched with a C1, gas at elevated temperatures, damage free, using an ultrahigh vacuum system.","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"139 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132781610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"III-VI Interfacial Compounds","authors":"M. Kobayashi, D. Menke, R. Gunshor, D. Li, Y. Nakamura, N. Ōtsuka","doi":"10.1109/LEOSST.1991.638943","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.638943","url":null,"abstract":"In recent years there has been considerable activity involving the growth of a variety of heterojunctions such as 111-V/III-V and 11-VyII-VI. Unlike these homovalent heterostructures, ZnSe/GaAs and CdTe/InSb heterojunctions are characterized by a chemical valence mismatch at the interface. An investigation of the interfacial regions of ZnSe/GaAs and CdTeDnSb heterovalent structures are discussed. It had been previously speculated that the ZnSe/GaAs interfaces were associated with the presence of an interfacial layer of Ga2Seg [ 11. TEM studies of heterojunctions formed on Asdeficient GaAs surfaces indicated the presence of a uniform band interpreted as an interfacial compound having an average thickness of 2 monolayers. Image simulations strongly supported the identification of zincblende Ga2Seg as the interfacial layer [2]. A series of experiments was performed in which the GaAs epilayer surface stoichiometry was systematically varied prior to the nucleation of the ZnSe epilayer. Using C-V measurements, it was determined that the interface properties improved as the GaAs surface became increasingly As deficient. A procedure was devised to provide a deliberate method to form the interfacial layer. The procedure involved the intentional reaction of Se with a (4x3) GaAs surface prior to the nucleation of ZnSe. Figure 1 shows in situ X P S spectra from Se3d and Ga3d core levels for a ~ ( 4 x 4 ) GaAs epilayer, a (2x1) Se-stabilized ZnSe epilayer, a deliberately grown Ga2Seg epilayer, and a Se-reacted layer. It is apparent that the line shape of the Se3d features originating from the Se-reacted layer, and those from the Ga2Se3 epilayer are quite similar. The Se-reacted layer and the Ga2Seg epilayer both show two doublets of comparable magnitude for which the area ratio of the high binding energy feature to the low binding. enerev feature is 2:l","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124379070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Etch Resistance Of Focused-ion-beam-implanted SiO/sub 2/","authors":"B. Geil, S. Merritt, G. Simonis, M. Dagenais","doi":"10.1109/LEOSST.1991.639022","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.639022","url":null,"abstract":"The etch rate of CVD Si02 in buffered hydrofluoric acid (BHF) is reduced after implantation with a 15 to 25 keV gallium focused ion beam (FIB). This effect is of interest for direct-write patterning of submicron Si02 features for semiconductor strain-confined quantum wires, quantum dots, for impurityor vacancy-induced disordering in optoelectronic integrated circuits and for fabrication lithography for other devices. Direct write into Si02 eliminates several lithographic steps and, if combined with dry etch development techniques, is of interest for use in multi-chamber all-vacuum processing.1 This approach also minimizes implant damage in the semiconductor sample. We investigated the effect of gallium ion dose on the etch rate of CVD Si02 in 2: 1,7: 1, and 20:l BHF. Regions of 5x70 pm2 area on these samples were implanted with the Micrion 808 FIB using a 0.15-pm FWHM beam. The dose was varied from 0.01 to 0.16 nC/pm2. The samples were etched in BHF, rinsed in deionized water, and profiled using a Tencor Alpha-Step 200 profilometer. The thickness of the unimplanted Si02 and the step height, or contrast, of the implanted region relative to the unimplanted region were measured as a function of etch time.The data obtained with a 7: 1 BHF etchant show the step height is a function of implant dose, with an optimum dose of about 0.04 nC/pm2 = 2 . 5 ~ 1 0 ~ ~ ions/cm2 (see Fig. 1). The effect of implantation is essentially to delay the onset of the normal etch rate. An optimum dose exists because of two competing effects: f i i t , a dose-dependent substantial reduction of the etch rate in the thin (hundreds of Angstroms) implanted Si02 layer and second, FIB milling removal of the implanted SiO2. The transition between reduced and normal etch rates was also investigated using other strengths of BHF solution at an FIB energy of 25 keV. 20:l BHF is shown in Fig. 2 Comparable step heights were observed for a 15 keV FIB energy. The optimum-dose Si02 step heights for the 25 keV data were 985, 1625, and 3500 Angstroms for 20:1,7:1, and 2: 1 BHF, respectively. This phenomenon appears similar to etch rate reduction found in boron doped glass (BSG) etched in 1O: l BKF 2. Gallium oxides, if present, would be expected to have a corresponding effect.","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129554086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication Of Grating-surface-emitting Semiconductor Lasers","authors":"G. Evans, N. Carlson, J. Hammer, D. Bour, J. Kirk, S. Liew, H. Lee, W. Reichert, R. Defreez, C.A. Wang, H.K. Choi, J. Walpole, J. Butler","doi":"10.1109/LEOSST.1991.638988","DOIUrl":"https://doi.org/10.1109/LEOSST.1991.638988","url":null,"abstract":"A sketch of a grating-surface-emitting (GSE) laser is shown in Fig. 1. The gratings between the gain sections provide feedback for laser oscillation in second order and couple out the laser radiation perpendicular to the surface in both directions in first order. With proper choice of grating parameters, a portion of the light is passed completely through each grating section and serves to injection lock additional gain sections in the longitudinal direction. GSE laser array technology has experienced steady progress over the last two years [ 11. Improvements in material quality and uniformity have made it possible to coherently couple two dimensional GSE lasers over distances larger than 1 cm. These devices can produce peak outputs of 32 W per surface and continuous power outputs of over 3 W per surface With differential quantum efficiencies of > 40 % per surface. Variations on the basic GSE laser concept have resulted in Master Oscillator Power Amplifier (MOPA) GSE arrays [2,3] and GSE devices with active grating outcoupling [4,5]. GSE arrays with 10 elements per gain section and 20 gain sections have obtained cw threshold current densities of under 140 A/cm2. Linewidths in the 30 to 60 MHz range have been obtained with output powers of 100 to 250 mW/surface.","PeriodicalId":435740,"journal":{"name":"LEOS 1991 Summer Topical Meetings on Epitaxial Materials and In-Situ Processing for Optoelectronic Devices. Photonics and Optoelectronics","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127069806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}