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1.
《Electron Device Letters, IEEE》1984,5(3):78-81
A capless annealing method for GaAs, employing short (1-10-s) thermal heat pulses from a graphite strip heater, is described. Results with29Si+ implanted into semi-insulating chromium-doped HB and chromium-doped LEC GaAs are presented. The samples were annealed at temperatures as high as 1000°C in a stationary N2 atmosphere with the implanted surface in close contact with a flat graphite strip heater surface. The wafers were covered with a graphite lid, effectively confining the volatile arsenic to a very small volume around the sample and providing a uniform temperature environment. Implantation efficiencies were high, and the quality of the implanted surface remained excellent after annealing. 相似文献
2.
The authors emphasize controlled shallow doping of GaAs by ion implantation and its limitations to state-of-the-art GaAs IC technology. The authors discuss the electrical activation behavior of implanted silicon in GaAs upon subsequent capless or silicon nitride capped rapid thermal annealing (RTA). It is demonstrated that atomic H diffuses into the implanted region of GaAs from a plasma-enhanced chemical vapor deposition Si3N4 cap during the deposition as well as during subsequent annealing, and the H retards the electrical activation kinetics of the implanted Si. Thru-Si cap dopant implants into GaAs have been studied to enhance dopant concentration in the surface region of the GaAs by recoil-implanted Si from the cap. Application of ion implantation to achieve buried-p layers in GaAs is also briefly discussed 相似文献
3.
Incoherent light from high-intensity halogen lamps was used for capless annealing of 2-inch GaAs wafers following silicon ion implantation. Fabrication of depletion mode MESFETs on the annealed wafers was used to study the DC characteristics and uniformity achieved with this annealing method. An average mutual transconductance of 110 mS/mm was obtained with MESFET fabricated wafers which were uniformly implanted at 5 × 1012 cm?2 with Si+ at 80 keV and subsequently annealed at 900°C for 2 s. The carrier concentration profiles obtained with this method are shown to be sharper than those obtained with furnace annealed wafers, which in turn results in a sharper device pinch-off voltage. 相似文献
4.
Rapid thermal annealing (RTA) technology offers potential advantages for GaAs MESFET device technology such as reducing dopant
diffusion and minimizing the redistribution of background impurities. LEC semi-insulating GaAs substrates were implanted with
Si at energies from 100 to 400 keV to doses from 1 × 1012 to 1 × 1014/cm2. The wafers were encapsulated with Si3N4 and then annealed at temperatures from 850-1000° C in a commercial RTA system. Wafers were also annealed using a conventional
furnace cycle at 850° C to provide a comparison with the RTA wafers. These implanted layers were evaluated using capacitance-voltage
and Hall effect measurements. In addition, FET’s were fabricated using selective implants that were annealed with either RTA
or furnace cycles. The effects of anneal temperature and anneal time were determined. For a dose of 4 × 1012/cm2 at 150 keV with anneal times of 5 seconds at 850, 900, 950 and 1000° C the activation steadily increased in the peak of the
implant with overlapping profiles in the tail of the profiles, showing that no significant diffusion occurs. In addition,
the same activation could be obtained by adjusting the anneal times. A plot of the equivalent anneal times versus 1/T gives
an activation energy of 2.3 eV. At a higher dose of 3 × 1013 an activation energy of 1.7 eV was obtained. For a dose of 4 × 1012 at 150 keV both the RTA and furnace annealing give similar activations with mobilities between 4700 and 5000 cm2/V-s. Mobilities decrease to 4000 at a dose of 1 × 1013 and to 2500 cm2/V-s at 1 × 1014/cm2. At doses above 1 × 1013 the RTA cycles gave better activation than furnace annealed wafers. The MESFET parameters for both RTA and furnace annealed
wafers were nearly identical. The average gain and noise figure at 8 GHz were 7.5 and 2.0, respectively, for packaged die
from either RTA or furnace annealed materials. 相似文献
5.
Numerous commercially available semi-insulating GaAs substrates have been implanted with silicon ions and the post implantation annealing carried out using the technique of capless annealing in an arsine atmosphere. Results are presented on the implanted atomic silicon distribution along with carrier concentration and mobility profiles, Hall mobility and percentage activation figures for various implanted substrates. The phenomenon of thermally induced surface conduction layers in semi-insulating GaAs is discussed in the context of a capless annealing technique. 相似文献
6.
Recent results of a capless method of annealing ion implanted GaAs are reported. The physical mechanism and effectiveness of the process are described and comparison of doping profiles from wafers annealed with a reactively sputtered Si3N4 dielectric encapsulation and with the capless process is given. Capless annealing is shown to consistently result in narrower profiles for various dopants and implant energies. The observed differences are shown to be consistent with enhanced diffusion in the dielectric capped samples, and the effective diffusion coefficients, which are of the order of 10?15 cm2/s for Se, differ by as much as a factor of two. 相似文献
7.
Carey A. Pico Michael A. Lieberman Nathan W. Cheung 《Journal of Electronic Materials》1992,21(1):75-79
The feasibility of plasma immersion ion implantation (PHI) for multi-implant integrated circuit fabrication is demonstrated.
Patterned Si wafers were immersed in a BF3 plasma forp-type doping steps. Boron implants of up to 3 × 1015 atoms/cm2 were achieved by applying microsecond negative voltage (-2 to -30 kV) pulses to the wafers at a frequency of 100 Hz to 1
kHz. After implantation the wafers were annealed using rapid thermal annealing (RTA) at 1060° C for 20 sec to activate the
dopants and to recrystallize the implant damaged Si. For the PMOS process sequence both the Si source-drain and polycrystalline
Si (poly-Si) gate doping steps were performed using PIII. The functionality of several types of devices, including diodes,
capacitors, and transistors, were electrically measured to evaluate the compatibility of PIII with MOS process integration. 相似文献
8.
《Electron Device Letters, IEEE》1986,7(1):13-15
Be-implanted GaAs are annealed by rapid thermal annealing (RTA) using halogen lamps. Electrical properties of the annealed GaAs are investigated, emphasizing those at 77K for application to the p+-layer of Be-implanted WSix -gate self-aligned two-dimensional hole gas (2- DHG) FET. An electrical activation of 90 percent (for 2.0 × 1013cm-2) or 80 percent (for 2.2 × 1014cm-2) is obtained. An annealing temperature dependence of carrier freezing at 77K is observed for higher dose samples. The phenomenon is attributed to the redistribution of impurity atoms near the high-concentration peak. 相似文献
9.
《Electron Device Letters, IEEE》1984,5(5):133-135
Composite TaSi2 /n+ poly-Si structures have been formed by rapid thermal annealing (RTA). Polysilicon films 0.2 µm thick were deposited on oxidized Si wafers by LPCVD and heavily doped with phosphorus by diffusion. A layer of TaSix 0.22 µm thick was then cosputtered on polysilicon from separate targets. The as-deposited samples were annealed by RTA using high-intensity tungsten lamps. Uniform stoichiometric low-resistivity tantalum disilicide was formed by RTA in 1 s at 1000°C. The sheet resistance and grain size of the silicide layers are comparable to those formed by conventional furnace anneals. The surface morphology of the RTA samples is superior to that obtained by furnace annealing. These results show that RTA technique has a great potential for low-resistivity tantalum silicide formation in VLSI circuits. 相似文献
10.
11.
本文报导了LEC法半绝缘砷化镓单晶中含碳量对SI-GaAs热稳定性的影响。在800℃以上退火,发现当晶体中C含量大于1.5×10~(16)cm~(-3)时,SI-GaAs的热稳定性变差;而C含量小于5×10~(15)cm~(-3)时,通常表现出良好的热稳定性。 相似文献
12.
C. S. Ma P. W. Chan V. C. Lo C. W. Ong S. P. Wong 《Journal of Electronic Materials》1994,23(5):459-464
Deep level photoluminescence of rapid thermal annealed (RTA) undoped liquid-encapsulated Czochralski InP has been studied.
Aband occurring at 1.20 eV, not observed in as-grown sample, became a dominant deep level peak after a 10-s rapid thermal
annealing process. However, after high temperature or prolonged annealing, it disappeared again. Ion implantation by various
species such as phosphorus, argon, and tin was carried out. The 1.20-eV band observed after RTA was found to be suppressed
by the phosphorus-implantation but enhanced by tin implantation, suggesting that its origin may be due to the formation of
phosphorus vacancy single point defect. 相似文献
13.
《Electron Device Letters, IEEE》2008,29(12):1356-1359
14.
15.
《Electron Device Letters, IEEE》1987,8(5):185-187
The suitability of MBE-grown GaAs layers on Si substrates has been studied for ion-implanted GaAs MESFET technology. The undoped as-grown GaAs layers had a carrier concentration below 1014cm-3. Uniform Si ion implants into 4-µm-thick GaAs layers on Si were annealed at 900°C for 10 s, using a rapid-thermal-annealing (RTA) system. Both the activation and the doping profile were similar to those obtained in bulk semi-insulating GaAs under similar conditions. The SIMS profiles of Si and As atoms near the GaAs/Si heterointerface were identical before and after the RTA process, indicating negigible interdiffusion during the implant activation. Dual implants of a shallow n+ layer and an n-channel layer were used to fabricate GaAs MESFET's with a recess-gate technology. Selective oxygen ion implantation was used for device isolation. The maximum transconductance obtained was 135 mS/ mm compared to typical values of 150-180 mS/mm obtained in our laboratory on GaAs substrates in similar device structures. 相似文献
16.
在 95 0°C和 1 1 2 0°C温度下 ,对非掺杂半绝缘 LECGa As进行了不同 As气压条件下的热处理 ,热处理的时间为 2~ 1 4小时。发现不同 As压条件下的热处理可以改变 Ga As晶片的化学配比 ,并导致本征缺陷和电参数的相应变化。在 95 0°C和低 As气压条件下进行 1 4小时热处理 ,可在样品体内 (表面 1 5 0 μm以下 )引入一种本征受主缺陷 ,使电阻率较热处理前增加约 5 0 % ,霍尔迁移率下降 70 %。这种本征受主缺陷的产生是由于热处理过程中样品内发生了 As间隙原子的外扩散。提高热处理过程中的 As气压可以抑制这种本征受主缺陷的产生。真空条件下在 1 1 2 0°C热处理 2~ 8小时并快速冷却后 ,样品中的主要施主缺陷 EL2浓度约下降一个数量级 ,提高热处理过程中的 As气压可以抑制 EL2浓度下降。这种抑制作用是由于在高温、高 As气压条件下 ,发生了间隙原子向样品内部的扩散 相似文献
17.
Formation and analysis of shallow arsenic profiles 总被引:1,自引:0,他引:1
Clayton S. Springer L. Offord B. Sedgwick T. Reedy R. Michel A. Scilla G. 《Electronics letters》1988,24(14):831-833
Shallow arsenic implants were activated by furnace and rapid thermal annealing (RTA). Comparisons of junction depths measured by secondary ion mass spectrometry (SIMS) and spreading resistance (SR) showed SIMS values 50-90 nm deeper than SR values, due to ion knock-on during SIMS profiling 相似文献
18.
Close contact rapid thermal annealing of semi-insulating GaAs:Cr implanted with Si, Si + Al, and Si + P has been studied using
variable temperature Hall effect measurements and low temperature (4.2K) photoluminescence (PL) spectroscopy. Isochronal (10
sec) and isothermal (1000° C) anneals indicate that As is lost from the surface during close contact annealing at high anneal
temperatures and long anneal times. Samples which were implanted with Si alone show maximum activation at an annealing temperature
of 900° C, above which activation efficiency decreases. Low temperature Hall and PL measurements indicate that this reduced
activation is due to increasing auto-compensation of Si donors by Si acceptors at higher anneal temperatures. However, co-implantation
of column V elements can increase the activation of Si implants by reducing Si occupancy of As sites and increasing Si occupancy
of Ga sites, and therebyoffset the effects of As loss from the surface. For samples implanted with Si + P, activation increases continuously up to a maximum at an anneal temperature
of 1050° C, and both low temperature Hall and PL measurements indicate that autocompensation does not increase in this case
as the anneal temperature increases. In contrast, samples implanted with Si + Al show very low activation and very high compensation
at all anneal temperatures, as expected. The use of column V co-implants in conjunction with close contact RTA can produce
excellent donor activation of Si implanted GaAs. 相似文献
19.
JIN Rui-min ZHENG Xiao-yan CHEN Lan-li LUO Peng-hui GUO Xin-feng LU Jing-xiao 《半导体光子学与技术》2009,15(2):117-119
Amorphous silicon films prepared by PECVD on glass substrate were crystallized by conventional furnace annealing (FA) and rapid thermal annealing ( RTA),respectively. From the Raman spectra and scanning electronic microscope(SEM),it found that the thin films made by RTA had smooth and perfect structure,while the thin films annealed by FA had a higher degree of structural disorder. 相似文献
20.
Rapid thermal annealing (RTA) of neutron transmutation doped Si wafers is shown to be an alternative to conventional furnace
annealing. Measurements of resistivity and deep level transient spectroscopy (DLTS), demonstrated annealing on wafers with
diameters up to 75 mm. A 4.5 kW incoherent-light RTA furnace was used. Evidence for crystalline slip was found but this did
not appear to affect the results. The slip was more severe for the larger diameter wafers. Some results from a DLTS examination
of a partially rapid-thermal-annealed wafer are presented. 相似文献