A model of secondary radiation damage accumulation during ion implantation is suggested. It is assumed that the dominating processes during radiation damage are the diffusion of simplest defects, their coagulation into complexes which are stable under implantation temperature, and capture of diffusing defects by traps. The dependence of the secondary complex concentration on the dose rate, target temperature, dose and the depth distribution of these complexes for different trap concentrations, and degrees of absorption of mobile defects a t the surface of the crystal are derived. npcl HOHHO# aMnnaHTauua. IlpennonaraeTcH, ¶TO noMmclpymuclMcl npoqeccaMn ue@eKToB, EIX Koarymum B KoimaeKcbI, KoTopMe ycToikclBbI npa TeMnepaType npenJIaraeTCH MOneJIb HaKOnJIeHMR BTOpMqHOfi PanMaUkIOHHOfi UeQeKTHOCTH B @OPMclPOBaHHki PanHaUkiOHHOfi He@eKTHOCTEI RBJIRIOTCH : lI[A@@Y3llH IIpOCTefiLLIllX MMlIJIaHTaUHH, 3aXBaT Acl@@YHHMPYH)UIclX Ae@KTOB BHYTpeHHEIMM CTOKaMM. nOny ¶eHbI 3aBITCMMOCTb KOHUeHTpaukicl BTOPHrIHbIX KOMnJleKCOB OT nJIOTHOCTEI HOHHOrO TOKB, TeMnepaTypbI MMUIeHU, n O 3 b I M PaCnpeHeJIeHMR BTMX KOMnJIeKCOB no r n y 6~a e lIJIR pa3JlkisHbIX KOHUeHTpaUM# JIOByWeK 1.I CTeneHM IIOrJIOUeHLIR IIO&BUm-HbIX He@eKTOB Ha ITOBepXHOCTEI KpclCTaJIJIa.

The phase composition of aluminium films after bombardment with boron, carbon, nitrogen, phosphorus, and arsenic ions is investigated by the electron‐diffraction method. It is shown that in all the cases except of bombardment with B+ ions the known compounds of aluminium with the indicated species are formed. The phase formed as a result of B+ bombardment could not be identified with the known aluminiumborides. It is shown that the texture of the formed phases is determined by the texture of the initial aluminium films indicating the epitaxial (or endotaxial) character of growth of these phases. In some cases AIP and AlAs phases are formed in an amorphous state. This is explained by insufficient substrate temperature for the crystallization or by amorphization under ion beam action. It is further shown that at bombardment of α‐iron films with C+ ions ϵ‐carbide is formed which after annealing at T ≧ 300 °C transforms into cementite.

No abstract

Pecularities of amorphous layer production in silicon under ion bombardment with middle energy ions were examined by electron diffraction. He4, B11, C12, N14, Ne20, P31, Ar40, As75, and Xe131 ion beams with energy of 50 keV were used. It was established that for light ions in a definite range of doses two amorphous layers are formed — an external layer and an internal one (sandwich structure). Doses necessary for amorphization and the thicknesses of the amorphous layers were determined. The results are discussed in terms of a model connected with the radiation defect accumulation. It is shown that for heavy ions the amorphization doses and the thicknesses of amorphous layers agree with the calculated distribution and concentration of radiation defects without taking account of their migration and annealing; for light ions under the given experimental conditions it is necessary to take account of the decreasing of a number of defects in the zone of displacements due to their migration and (or) annihilation.

The effective values (i.e. values calculated supposing compensation to be absent) of the ionization energies Ea, d of boron and phosphorus introduced into silicon by ion implantation are determined using Hall measurements. At annealing temperatures ≦ 500 °C, Ed for phosphorus exceeds the “normal” values associated with the presence of compensation by acceptor levels of radiation defects. Under the same conditions the compensation degree is higher for specimens cut out perpendicularly to the [110] axis in comparison with specimens of [111] orientation. For boron in p‐type silicon an increase is found of the effective ionization energy (in comparison with the usual one); Ea first grows with dose (up to 2 × 1014 ions/cm2) and then decreases. For n‐type silicon irradiated with boron, an effective deepening of the level is observed at small doses only and is explained as being due to compensation. An explanation of the mentioned regularities is suggested.