Science of dry etching of III-V materials

The hydrogenation of crystalline Si by methods used to passivate defects in Si solar cells has been studied by infrared spectroscopy. For these experiments, floating-zone Si that contained Pt impurities that act as traps for H was used as a model system in which H could be directly detected. In this model system, the concentration and indiffusion depth of H were determined for different hydrogenation treatments so that their effectiveness could be compared. The postdeposition annealing of a hydrogen-rich SiN x surface layer was found to introduce H into the Si bulk with a concentration of ϳ10 15 cm −3 under the best conditions investigated here.

Section: Diffusivity Of H During Hydrogenation Treatmentsmentioning

confidence: 99%

Concentration and penetration depth of H introduced into crystalline Si by hydrogenation methods used to fabricate solar cells

Kleekajai

Jiang

Stavola

et al. 2006

“…It is assumed that the isolation is provided by carrier trapping at deep energy levels in the forbidden band gap associated to the irradiation damage ͑defect isolation͒ or to specific impurities used for irradiation ͑chemical isolation͒. 1,2 Since the defect isolation process is much more versatile and simpler than chemical isolation, it is preferred for industrial applications.…”

Section: Introductionmentioning

confidence: 99%

Electrical isolation of p-type GaAs layers by ion irradiation

Boudinov

Coelho

Souza

2002

The electrical isolation of p-type GaAs layers doped with acceptor impurities incorporated in the Ga sublattice ͑Mg͒ or As sublattice ͑C͒ was studied using proton bombardment. It was found that practically the same proton dose is required to reach complete isolation ͑isolation threshold dose, D th ͒ in layers doped with either Mg or C of comparable original sheet hole concentration (p s ). This result is evidence that the sublattice where the acceptor dopant atoms are incorporated does not play any significant role for the isolation formation process in GaAs. The behavior of the recovery of the conductivity during subsequent thermal annealing was found very similar in Mg and C doped samples irradiated to equal proton doses. In samples irradiated to doses ϽD th , the sheet resistance (R s ) increases during annealing at temperatures Ͼ100°C, reaches a maximum at Х200°C, and then decreases progressively toward the original value. For proton doses ranging from D th to 5D th , the isolation is preserved up to the temperature of Ϸ500°C. The temperature of Ϸ700°C was found to be the upper limit for the thermal stability of the isolation in samples irradiated to doses of 100 D th .

“…An implant isolated region in a semiconductor device may be used as a potential alternative to mesa etching, offering simplicity, precise depth control, and compatibility with planar technology. 4,5 The ion implantation technique for electrical isolation will hereafter be called ion irradiation. The degree of electrical isolation after ion irradiation and low temperature annealing ͑100-500°C͒ is sometimes superior to that provided by mesa structures.…”

Section: Introductionmentioning

confidence: 99%

Electrical isolation of n-type and p-type InP layers by proton bombardment

Boudinov

Tan

Jagadish

2001

The evolution of the sheet resistance (R s ) of n-type and p-type conductive InP layers during proton irradiation and the stability of the formed isolation during postirradiation annealing were investigated. It was found that the threshold dose (D th ) to convert the conductive layer to a highly resistive one is different for n-and p-type samples with similar initial free carrier concentrations. From our results, one infers that the antisite defects and/or related defect complexes formed by the replacement collisions are the carrier trapping centers, where In P is responsible for electron trapping and P In for the hole trapping. A time dependence of the R s was observed after each irradiation step to doses of ХD th and higher. This time variation is related to metastable processes involving free carriers. The thermal stability of the isolation of n-type samples is limited to temperatures lower than 200°C, irrespectively of the irradiated dose. For p-type samples the thermal stability of electrical isolation is extended to 450-500°C.