Ultra-thin SiN Research Articles

Investigation of ultra thin SiN xO y layers produced by low-energy ion implantation with NRA and channeling-RBS

Near surface SiN x O y layers are produced by molecular ion implantation of 15N 2 18O into c-Si at RT. 15N and 18O depth profiles are analysed by the resonant nuclear reactions 15N (p, αγ) 12C ( E res = 429 keV; Γ res = 120 eV) and 18O(p, α) 15N ( E res = 152 keV; Γ res = 50 eV), respectively. The disorder at the SiN x O y /Si interface is obtained by channeling-RBS ( 4He +, E 0 = 1.7 MeV). After processing by electron beam rapid thermal annealing (peak temperature T = 1100°C for t = 15 s, ramping up and down 5°C/s) no changes in the depth distributions are obtained, whereas the thickness of the disordered region beneath the implanted layer decreases depending on the annealing process. The channeling-RBS spectra are compared with spectra simulated by the MABIC code.

High-speed (104 °C/s) scanning microcalorimetry with monolayer sensitivity (J/m2)

We introduce a high sensitivity (1J/m2) scanning microcalorimeter that can be used at high heating rates (104 °C/s). The system is designed using ultrathin SiN membranes that serve as a low thermal mass mechanical support structure for the calorimeter. Calorimetry measurements of the system are accomplished via resistive heating techniques applied to a thin film Ni heating element that also serves as a thermometer. A current pulse through the Ni heater generates heat in the sample via Joule heating. The voltage and current characteristics of the heater were measured to obtain real-time values of the temperature and the heat delivered to the system. This technique shows potential for measuring irreversible heat of reactions for processes at interfaces and surfaces. The method is demonstrated by measuring the heat of fusion for various amounts of thermally evaporated Sn ranging from 50 to 1000 Å.

Comparative study of the properties of ultrathin Si3N4 films with Auger electron spectroscopy, spectroscopic ellipsometry, and Raman spectroscopy

Ultrathin Si3N4 films are characterized with Auger electron spectroscopy, spectroscopic ellipsometry (SE), and Raman spectroscopy (RS). It is shown that Ar+ sputtering induces preferential nitrogen sputtering which causes problems in the determination of the interface location. Film thickness measurements with the nondestructive SE technique result in film thicknesses systematically larger than those calculated from the Auger sputter profiling, for films thinner than 100 Å. Furthermore, analysis of the SE and RS data shows that the films are dense and stoichiometric while the stress induced by the Si3N4 film on the Si substrate amounts to 2–3 kbar.