The photoluminescence (PL) and electroluminescence (EL) properties of Ge-implanted SiO2 layers thermally grown on a Si substrate were investigated and compared to those of Si-implanted SiO2 films. The PL spectra from Ge-implanted SiO2 were recorded as a function of annealing temperature. It was found that the blue-violet PL from Ge-rich oxide layers reaches a maximum after annealing at 500 °C for 30 min, and is substantially more intense than the PL emission from Si-implanted oxides. The neutral oxygen vacancy is believed to be responsible for the observed luminescence. The EL spectrum from the Ge-implanted oxide after annealing at 1000 °C correlates very well with the PL one, and shows a linear dependence on the injected current. The EL emission was strong enough to be readily seen with the naked eye and the EL efficiency was assessed to be about 5×10−4.

The formation of helium induced cavities in silicon is studied as a function of implant energy (10 and 40 keV) and dose (1×1015, 1×1016, and 5×1016 cm−2). Specimens are analyzed after annealing (800 °C, 10 min) by transmission electron microscopy (TEM) and elastic recoil detection (ERD). Cavity nucleation and growth phenomena are discussed in terms of three different regimes depending on the implanted He content. For the low (1×1015 cm−2) and high (5×1016 cm−2) doses our results are consistent with the information in the literature. However, at the medium dose (1×1016 cm−2), contrary to the gas release calculations which predict the formation of empty cavities, ERD analysis shows that a measurable fraction of the implanted He is still present in the annealed samples. In this case TEM analyses reveal that the cavities are surrounded by a strong strain field contrast and dislocation loops are generated. The results obtained are discussed on the basis of an alternative nucleation and growth behavior that allows the formation of bubbles in an overpressurized state irrespective of the competition with the gas release process.

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.

Experiments are reported which explore the possibility of using low-temperature, multiple-energy Si+ ion implantation into thin SiO2 films on Si and subsequent short-time thermal processing to form silicon nanostructures capable of yielding a high-intensity emission in the short-wavelength part of the visible spectrum. A room-temperature short-wavelength PL band of high intensity was found after double implantation with energies of 200 and 100 keV at a temperature of −20 °C to a total dose of 4.8×10 16 cm−2 (atomic concentration about 2×1021 cm−3) and subsequent furnace annealing at 400 °C for 0.5 h in forming gas or by flash lamp annealing at 1050 °C for 20 ms.