Physical and Electrical Characteristics of Methylsilane- and Trimethylsilane-Doped Low Dielectric Constant Chemical Vapor Deposited Oxides

Abstract

This work investigates the physical and electrical properties of two species of inorganic C-doped low dielectric constant ͑low-k͒ chemical vapor deposited ͑CVD͒ organosilicate glasses ͑OSGs, ␣-SiCO:H͒. They are both deposited by plasma-enhanced CVD ͑PECVD͒ processes using methylsilane ͓͑CH 3 ͒SiH 3 , 1 MS͔-and trimethylsilane ͓͑CH 3 ͒ 3 SiH, 3 MS͔-based gases as the reagents, and are designated as OSG1 and OSG2, respectively. Experimental results indicate that the thermal stability temperature of OSG1 is 500°C, while that of OSG2 is 600°C, based on the results of thermal annealing for 30 min in an N 2 ambient. The deterioration of the low-k property in OSG1 is predominately due to the thermal decomposition at temperatures above 500°C of methyl (ϪCH 3) groups, which are introduced to lower the density and polarizability of OSGs. For the Cu-gated oxide-sandwiched low-k dielectric metal-insulator-semiconductor ͑MIS͒ capacitors, Cu permeation was observed in both OSG1 and OSG2 after the MIS capacitors were bias-temperature stressed at 150°C with an effective applied field of 0.8 MV/cm. Moreover, Cu appeared to drift more readily in OSG1 than in OSG2, presumably because OSG1 has a more porous and less cross-linked structure than OSG2. The Cu penetration can be mitigated by a thin nitride dielectric barrier.

Low–Dielectric Constant Insulators for Future Integrated Circuits and Packages

“…The cage structure has eight silicon atoms at the vertices of a cube. Although the silica structure is stable at high temperature, SQ compounds in the cage structure are highly sensitive to thermally activated redistribution processes and to oxidation at temperatures greater than 350 • C in the presence of even low levels (ppm) of oxygen (68)(69)(70). Another issue with SQ compounds is the absorption of moisture (71,72).…”

Properties of Hydrogenated Nanoporous SiC: An Ab Initio Study

“…Figure 5 illustrates a bulk SiC unit cell versus a unit cell with a single pore. Applying classical dielectric theory to the unit cell with a nanopore (Figure 5(b)), the total dielectric constant ( npSiC ) can be written as [10,23]…”

An Electrical, Compositional, and Structural Study on Low-k Silsesquioxane Dielectric Thin Films

“…5a͒, and it is mostly caused by moisture evaporation from either the surfaces or interfaces of the powder particles at the temperatures below 100°C. Standard technology of the MSQ films allows one to avoid strong moisture absorption, 27,28 and it results in lower relative changes in density of our material during its thermal treatment up to 400°C. Further T a increment till 500°C leads to the density increment of only about 0.003 g/cm 3 .…”