A parylene coating system specifically designed for producing ultra-thin films for nanoscale device applications

Abstract

We report on a parylene chemical vapor deposition system custom designed for producing ultra-thin parylene films (5 − 100 nm thickness) for use as an electrical insulator in nanoscale electronic devices, including as the gate insulator in transistors. The system features a small deposition chamber that can be isolated and purged for process termination, a quartz crystal microbalance for monitoring deposition, and a rotating angled stage to increase coating conformity. The system was mostly built from off-the-shelf vacuum fittings allowing for easy modification and reduced cost compared to commercial parylene coating systems. The production of ultra-thin parylene films for device applications is a niche not well catered to by commercial coating systems, which are typically designed to give thicker coatings (microns) with high uniformity over much larger areas. An added advantage of our design for nanoscale device applications is that the small deposition chamber is readily removable for transfer to a glovebox to enable parylene deposition onto pristine surfaces prepared in oxygen/water-free environments with minimal contamination.

The Photo‐Hall Effect in High‐Mobility Organic Semiconductors

“…Such radicals are the essential intermediate species generated during the parylene growth process. [ 60,61 ] A few of these monomers might be trapped in the parylene‐ N film right next to the interface with the crystal and create energetic trap states for mobile holes flowing in rubrene. Eventually, they will be gradually passivated via crosslinking with neighboring polymer units, thus leading to a recovery of σ PC .…”

Nonvolatile Memory Action Due to Hot-Carrier Charge Injection in Graphene-on-Parylene Transistors

“…The SiO 2 is a thermal oxide prepared by well-established routes, and the parylene C is deposited on top by a chemical vapor deposition (CVD) process involving three stages: sublimation of the di- p -xylylene dimer at ∼120 °C, cracking into reactive monomers at ∼700 °C, and polymerization at room temperature onto the substrate, all at moderate vacuum. This process is performed in a CVD system custom-designed to give ultrathin parylene films (<100 nm) with sufficient quality for electronic device applications. , For this study the key point is that the combined thickness of SiO 2 (200 nm, refractive index n = 1.47) and parylene (70 nm, n = 1.66) (see Figure a) was chosen to be equivalent to 280 nm of a single layer of SiO 2 to retain the optical conditions favorable to graphene device fabrication . The resulting dielectric stack exhibited the purple tinge (see Figure c, inset) that is typical of such an oxide layer, making it easier to locate graphene flakes with an optical microscope.…”

“…This process is performed in a CVD system custom-designed to give ultrathin parylene films (<100 nm) with sufficient quality for electronic device applications. 10,32 For this study the key point is that the combined thickness of SiO 2 (200 nm, refractive index n = 1.47) and parylene (70 nm, n = 1.66) (see Figure 2a) was chosen to be equivalent to 280 nm of a single layer of SiO 2 to retain the optical conditions favorable to graphene device fabrication. 17 The resulting dielectric stack exhibited the purple tinge (see Figure 2c, inset) that is typical of such an oxide layer, making it easier to locate graphene flakes with an optical microscope.…”

Chemically Tunable Organic Dielectric Layer on an Oxide TFT: Poly(p-xylylene) Derivatives

“…The vapor deposition method using PPx dimers was first proposed by Gorham . The PPx coating method has been further improved to allow thickness control below 100 nm . PPx has excellent chemical resistance and physical properties and low gas and moisture permeability.…”

“…18 The PPx coating method has been further improved to allow thickness control below 100 nm. 19 PPx has excellent chemical resistance and physical properties and low gas and moisture permeability. In addition, the electrical strength is high, and the dielectric constant is measured to be around 3.…”