Deposition of SiNx:H thin films by the electron cyclotron resonance and its application to Al/SiNx:H/Si structures

Abstract

We have analyzed the electrical properties and bonding characteristics of SiNx:H thin films deposited at 200 °C by the electron cyclotron resonance plasma method. The films show the presence of hydrogen bonded to silicon (at the films with the ratio N/Si<1.33) or to nitrogen (for films where the ratio N/Si is higher than 1.33). In the films with the N/Si ratio of 1.38, the hydrogen content is 6 at. %. For compositions which are comprised of between N/Si=1.1 and 1.4, hydrogen concentration remains below 10 at. %. The films with N/Si=1.38 exhibited the better values of the electrical properties (resistivity, 6×1013 Ω cm; and electric breakdown field, 3 MV/cm). We have used these films to make metal-insulator-semiconductor (MIS) devices on n-type silicon wafers. C–V measurements accomplished on the structures indicate that the interface trap density is kept in the range (3–5)×1011 cm−2 eV−1 for films with the N/Si ratio below 1.38. For films where the N/Si ratio is higher than 1.4, the trap density suddenly increases, following the same trend of the concentration of N–H bonds in the SiNx:H films. The results are explained on the basis of the model recently reported by Lucovsky [J. Vac. Sci. Technol. B 14, 2832 (1996)] for the electrical behavior of (oxide–nitride–oxide)/Si structures. The model is additionally supported by deep level transient spectroscopy measurements, that show the presence of silicon dangling bonds at the insulator/semiconductor interface (the so-called PbN0 center). The concentration of these centers follows the same trend with the film composition of the interface trap density and, as a consequence, with the concentration of N–H bonds. This result further supports the N–H bonds located at the insulator/semiconductor interface which act as a precursor site to the defect generation of the type •Si≡Si3, i.e., the PbN0 centers. A close relation between interface trap density, PbN0 centers and N–H bond density is established.

Low interface trap density in rapid thermally annealed Al/SiNx:H/InP metal–insulator–semiconductor devices

“…5,13 For that reason, a simultaneous decrease of dangling-bond density is obtained. 5,14 Since the dangling bonds are electrically active, a reduction of their concentration induced by RTA may also induce a decrease of D it at the interface according to the data of Fig. 3.…”

Electrical Characterization of High-K Dielectric Gates for Microelectronic Devices

“…These values do agree with those obtained when using HLCV technique. Moreover, this distribution show a profile consisting on broad gaussian peaks, as is usually reported for silicon nitride films [49][50][51][52][53]. …”

Electrical characterization of electron cyclotron resonance deposited silicon nitride dual layer for enhanced Al/SiNx:H/InP metal–insulator–semiconductor structures fabrication

“…In previous works, 13,14 we have studied the influence of the nitrogen content in the interface quality, and insulator film properties of dielectric layers deposited on different substrates. In particular, the samples studied were Al/SiN x :H/Si and Al/SiN x :H/InP.…”