Deposition of SiO₂ by Plasma Enhanced Chemical Vapor Deposition as the Diffusion Barrier to Polymer Substrates

Abstract

SiO 2 thin films were deposited at the temperatures < 150 C by plasma enhanced chemical vapor deposition (PECVD) using a tetraethylorthosilicate (TEOS)/N 2 /O 2 gas mixture, and the physical and chemical characteristics as well as the characteristics as a transparent diffusion barrier to H 2 O were investigated. Using a gas combination of TEOS(40 sccm)/O 2 (500 sccm)/ N 2 (100 sccm) at source power of 500 W and dc bias voltage of À350 V, SiO 2 with a stoichometric composition of SiO 2 and a smooth surface similar to the substrate could be deposited. When a multilayer diffusion barrier composed of parylene(800 nm)/SiO 2 (100 nm)/parylene(800 nm)/SiO 2 (100 nm)/parylene(800 nm) was formed on a polyethersulfone (PES) substrate, the water vapor transmission rate (WVTR) of the substrate was decreased from 54.1 to 0.3 gm/ (m 2 Áday).

Water diffusion coefficient measurements in deposited silica coatings by the substrate curvature method

“…It has been extensively studied and quantified by numerous techniques including infrared absorption [1][2][3][4] and Raman spectroscopy [5] of hydroxyl groups, water vapor transmission rate measurements [6], and secondary ion mass spectrometry of D 2 O [7]. This work applies a substrate curvature method previously used to deduce the room temperature diffusivity of water in polymer coatings [8] to deposited silica coatings.…”

Characteristics of SiOxNy films deposited by inductively coupled plasma enhanced chemical vapor deposition using HMDS/NH3/O2/Ar for water vapor diffusion barrier

“…4(b) shows the measured WVTRs of the multiple thin films deposited on the PES for a 60 nm-thick SiO x N y film. As references, the WVTRs of PES (200 μm) and PES (200 μm)/ parylene (800 nm) obtained from a previous experiment [1] were also included. As shown in the figures, the WVTRs of the PES (200 μm) and PES (200 μm)/parylene (800 nm) were 54.1 g/(m 2 day) and 40.4 g/(m 2 day), respectively.…”

“…can cause damage or a malfunction [1,2]. Therefore, permeation barrier films are used to enhance the lifetime of these devices.…”

Optical Constant and Conformality Analysis of SiO2 Thin Films Deposited on Linear Array Microstructure Substrate by PECVD

“…Conformality, conformal coverage, or step coverage are important for many applications such as array optical filters, microelectronics [7][8][9], integrated circuit technologies [10,11], and nano-imprint lithography [12,13]. The main methods of preparing SiO 2 thin films are physical vapor deposition (PVD), chemical vapor deposition (CVD), Sol-Gel method, and liquid precipitation deposition (LPD) [14][15][16][17]. Generally, when the thin film is deposited on a patterned substrate with CVD technology, it is easy to obtain good conformality, while it is difficult with PVD [18,19].…”