Bright green electroluminescence with luminance up to 2800 cd/ m 2 is reported from indium-tin-oxide/SiO 2 : Tb/ Si metal-oxide-semiconductor devices. The SiO 2 :Tb 3+ gate oxide was prepared by thermal oxidation followed by Tb + implantation. Electroluminescence and photoluminescence properties were studied with variations of the Tb 3+ ion concentration and the annealing temperature. The optimized device shows a high external quantum efficiency of 16% and a luminous efficiency of 2.1 lm/ W. The excitation processes of the strong green electroluminescence are attributed to the impact excitation of the Tb 3+ luminescent centers by hot electrons and the subsequent crossrelaxation from 5 D 3 to 5 D 4 energy levels. Light-emitting devices with micrometer size fabricated by the standard metal-oxide-semiconductor technology are demonstrated.
The use of flash lamp annealing for ultrashallow junction formation in silicon has been described. Low energy boron and arsenic implants have been heat-treated in this way using peak temperatures in the range of 1100 to 1300°C and effective anneal times of 20 and 3 ms. Secondary ion mass spectrometry and four-point probe measurements have been undertaken to determine the junction depth and the sheet resistance, respectively. Optimum processing conditions have been identified, under which one can obtain combinations of junction depth and sheet resistance values that meet the 90 nm technology node requirements and beyond.Source/drain junction depths need to be reduced in line with the continuing scaling down of deep submicrometer devices in silicon. Currently, the technique of choice for producing ultrashallow junctions ͑USJs͒ that meet the specifications of the sub-90 nm node relies on the use of ultralow energy boron ion implantation followed by extremely short time thermal annealing. 1-3 The key structural parameters of a USJ are the sheet resistance R s and junction depth X j . According to the International Technology Roadmap for Semiconductors (ITRS) 2003 4 the realization of the 90 nm node, whose year of production is 2004, calls for R s ഛ 663 ⍀/ᮀ and X j ഛ 20.4 nm. The respective values for the 65 nm node, which is scheduled for the year 2006 are R s ഛ 884 ⍀/ᮀ and X j ഛ 13.8 nm.Thermal annealing techniques such as rapid thermal processing ͑RTP͒ and, more recently, spike RTP 1-3,5,6 have been adequate to control the processing of mainstream devices. These annealing methods, however, will soon become unsuitable for the USJs required in the near future. The reason is that the effective anneal times 7 used are still relatively long, being in the order of 1 s or more. The fabrication of USJs necessitates both very high annealling temperatures for achieving high electrical activation, and extremely short times of heat-treatment to minimize the effect of dopant transient enhanced diffusion ͑TED͒ 8 responsible for the undesirable junction broadening. The attempts to meet these two competing requirements have led to great interest in the development of alternative ultrafast heat-treatment methods, of which laser thermal processing ͑LTP͒ 9 and flash-assisted RTP ͑fRTP™͒ 10,11 are presently among the most promising ones.The common feature of all ultrafast thermal annealing processes is the use of a small thermal budget involving a high peak temperature, T max , coupled with a very short effective time of the anneal cycle and very high ramp-up/cool-down rates. LTP has some inherent problems associated with dopant deactivation and process integration. In fRTP™, the device structure is exposed to a short duration pulse or flash ͑on the order of milliseconds͒ of intense light produced by an arc lamp.We have developed and tested successfully an alternative version of ultrarapid thermal processing based on the use of a xenon flash lamp system, hereafter referred to as the flash lamp annealing ͑FLA͒ technique. Results of a p...
The processes of electro- (EL) and photoluminescence (PL) and charge trapping in Er-implanted SiO2 containing silicon nanoclusters have been studied. It is shown that in Er-doped SiO2 with an excess of silicon nanoclusters of 10 at. %, a strong energy transfer from silicon nanoclusters results in a ten-fold increase of the PL peak at 1540 nm from Er luminescent centers, whereas the EL is strongly quenched by the excess silicon nanoclusters. It is further shown that the implantation of Er creates in the oxide positive charge traps with a giant cross section (σh0>10−13cm2). Introducing subsequent silicon nanocrystals in the oxide leads to the formation of negative charge traps of a giant cross section (σe0>10−13cm2). The possible reason for the EL quenching in the Er-doped SiO2 by silicon nanoclusters is discussed.
Efficient blue electroluminescence peak at around 440nm with a maximum output power density of 34mW∕cm2 was obtained from Ce and Gd coimplanted metal-oxide-semiconductor light emitting devices. Energy transfer from Gd3+ to Ce3+ ions was observed during the excitation process, leading to a more than threefold increase of the external quantum efficiency of the blue Ce3+ luminescence up to 1.8%. This is evidenced by the increase of the excitation cross section of Ce3+ ions from 4.8×10−13to3.5×10−12cm2 and the simultaneous reduction of the decay time and the impact cross section of Gd3+ ions.
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