Effect of Thermal Treatment on Carbon-Doped Silicon Oxide Low Dielectric Constant Materials

Abstract

Carbon-doped silicon oxide (SiOCH) low dielectric constant (low-k) material is a good candidate for advanced interconnect technology. Good thermal stability of the dielectric is required due to the many thermal processes involved during IC fabrication. The thermal stability of tetramethylcyclotetrasiloxane (TMCTS) based plasma-enhanced chemical vapor deposition (PECVD) carbon doped low-k material with annealing temperature from 400 to 800 degrees C in N2 was studied. The thermal stability temperature of TMCTS based carbon doped low-k material is 600 degrees C. Above 600 degrees C annealing, the thermal energy can break Si-CH3, Si-C, Si-H, and C-H bonds leading to outgasing, which results in film composition change, weight loss, and thickness shrinkage. Film composition changes, especially carbon loss and oxygen incorporation, can degrade its reliability extremely. Carbon is desorbed in the form of CH4, CO, and other hydrocarbon.

Optical and chemical characterization of expanding thermal plasma-deposited carbon-containing silicon dioxide-like films

“…The ex situ absorption at room temperature is added as reference (empty symbols). [45], suggesting that the annealing process should not alter the dielectric properties of the deposited films. After the samples are transferred to the vacuum chamber and heated, the water absorption (3250 cm − 1 ) decreases due to desorption of physisorbed water from the pores.…”

Electrical Properties of Selectively Deposited Graphene‐Like Film on Silicon Oxide/Silicon Structures Preirradiated with Low Energy Electrons

“…Indeed, carbon incorporation into silicon oxide is known to lowering oxide dielectric constant. [12] The GLF-gated MOS structures preirradiated with 3 keV electrons demonstrate quite different type of C-V characteristics. Figure 5a shows the C-V curves obtained after preirradiation with the dose of 500 μC cm À2 .…”

Porous SiOCH Thin Films Obtained by Foaming

“…It is difficult to formally identify the gas molecule produced during the curing: the literature mentions the possible formation of methane, carbon monoxide, and other hydrocarbons. 40 By analogy with a polymer foaming process, it can be assumed that methyls depleted during the UV curing act as the main source of gas which can coalesce in order to create porosity. The larger the methyl depletion is, the higher the creation of gases (probably hydrocarbons) and the creation of porosity are.…”