Evolution of shallow donors with proton fluence in n-type silicon

Abstract

Bipolar components that consist of p+n junctions have been irradiated by MeV protons at fluences ranging from 1011 to 1013 particles cm−2. Capacitance-voltage measurements have been used to investigate changes in the carrier concentration profiles. Shallow donors that can induce harmful effects in electronic devices have been studied as a function of fluence, flux, and annealing parameters.

Study of shallow donor formation in hydrogen-implanted n-type silicon

“…Fortunately, at the annealing temperatures where the formation of hydrogenrelated shallow donors occurred, carrier profiles almost coincided with each other irrespective of measurement temperatures, since the ratio of deep-trap concentration to shallow-donor concentration was reduced. The C-V measurement temperature was down to 30 K for such samples, and it was confirmed that carrier profiles were almost the same in the measurement temperature range 30 to 300 K. Furthermore, this result indicates that hydrogenrelated donors are indeed shallow donors as previously reported [3][4][5][6][7][8][9][10][11].…”

“…The carrier profiles are shown in figure 2 for hydrogen-implanted samples which are annealed at 300, 350, 400, 450, 500 and 550 • C. An increase in carrier concentration is observed at the annealing temperature of 300 • C with a concentration peak at the depth around the mean projected range R p = 0.86 µm of hydrogen implanted in this work whose value is revealed by the SIMS analysis as shown later in figure 3. This indicates the growth of the hydrogen-related shallow donors as reported previously [3][4][5][6]. It is noted that an increase in carrier concentration is seen in the shallower region than R p .…”

“…The zero-bias depletion layer width recovers to the pre-implantation value in the annealing temperature range 100 to 250 • C and becomes smaller in the range 300 to 450 • C. The decrease of the zero-bias depletion layer width in the range 100 to 250 • C is ascribed to the passivation of implantation-induced acceptor-type defects by hydrogen since the growth of hydrogen-related shallow donors has been reported to occur at annealing temperatures around 250 • C [3][4][5][6]. The smaller values of the zerobias depletion layer width indicate the presence of donors over the phosphorus donor concentration in the range 300 to 500 • C, consistent with the growth temperature range of hydrogen-related shallow donors.…”

“…There are several cases of formation of hydrogenrelated shallow donors, that is, hydrogen implantation [3][4][5][6], neutron transmutation doping in silicon grown in a hydrogen atmosphere [7,8], electron irradiation in silicon doped with hydrogen by annealing in an H 2 gas ambient at 1000 • C [9,10] and neutron transmutation doping and subsequent hydrogen-plasma treatment [11]. Hydrogenrelated shallow donors are formed in the temperature range 300 to 500 • C, although it is unclear whether the same kinds of donor are produced or not among these cases.…”

Strain and electrical characterization of metal-oxide-semiconductor field-effect transistor fabricated on mechanically and thermally transferred silicon on insulator films

“…It is well known that shallow donors are formed in CZ Si as a result of hydrogenation by implantation or with a rf source [33][34][35][36][37][38][39][40][41] followed by annealing at ϳ300°C or higher. Most of these donors are likely to be associated with H-enhanced thermal donors in CZ silicon due to the preponderance of interstitial oxygen O i .…”