Thermal Diffusion of Sodium in Silicon Nitride Shielded Silicon Oxide Films

Abstract

The ability of silicon nitride layers deposited on silicon oxide‐passivated silicon to act as contamination barriers has been measured through the use of a radioisotope, sodium‐22. Transport studies at 500°C have shown that the concentration of sodium reaching the silicon oxide‐silicon interface Was reduced one thousandfold when a 1000Aå shield of silicon nitride was present. These nitride films which may be deposited by any one of several techniques act not only as mechanical barriers against sodium penetration, but also as sodium getters. The amount of sodium retained by the silicon nitride film depends mainly on the film deposition temperature. For example, silicon nitride films deposited at 850°C trap more sodium than those deposited at 1100°C. The presence of moisture in the ambient atmosphere during any annealing process of a silicon nitride shielded silicon oxide film will release some of the sodium trapped in the nitride layer and allow it to move to the silicon oxide‐silicon interface.

Water Contamination in Thermal Oxide on Silicon

“…Furthermore, profiles for wet diffusions peaked at the silicon, which has been associated with image charge in the silicon (22). Such an effect has been previously noted (13). 7.…”

“…Increased sodium transport in the presence of water (13) and increased wet oxidation rates in the presence of sodium (12) have been shown. Increased sodium transport in the presence of water (13) and increased wet oxidation rates in the presence of sodium (12) have been shown.…”

A 250 <italic>μ</italic>m × 57 <italic>μ</italic>m Microscale Opto-electronically Transduced Electrodes (MOTEs) for Neural Recording

“…A related problem is appropriate encapsulation of MOTEs to allow reliable chronic implantation. Preliminary studies indicate that encapsulation using a combination of atomic layer deposition (ALD) of Si02, Si x N y , and parylene, often used for biological coatings [49, 51], should allow for >1 year of deployment. In addition, the silicon substrate of the CMOS requires an opaque coating (such as metal) to prevent excessive optical generation of carriers that can generate unwanted currents in the CMOS circuits.…”

Aqueous ionic effect on electrochemical breakdown of Si-dielectric–electrolyte interface

“…Yet how the metal ions travel within the dielectric layer and modify its properties is controversial. Impregnation of ions into the insulators mostly involves harsh conditions so that the intrinsic nature of insulator undergo severe changes far from its pristine state[24][25][26][27][28][29][30] , resulting in the inconsistency of experimental results. Therefore, the study on this type of system require a less invasive method that can minimally modify the property of as-deposited insulator film.…”