Stress Reduction of Amorphous Silicon Deposited by PECVD. (2nd March 2016)

• Record Type: Journal Article
• Authors: Pérez, César B.; Reyes-Betanzo, C.
• Editors: López-Cuevas, Jorge; Robles Hernandez, Francisco C.
• Is Part Of: MRS proceedings. Volume 1812(2016)
• Publication Date: 2016-03-02
• Subjects: Amorphous, -- Thermal stresses, -- Plasma-enhanced CVD (PECVD) (deposition); Electrical engineering -- Congresses; Physics -- Congresses; Materials -- Research -- Congresses; Materials science -- Congresses; 620.11
• DOI: 10.1557/opl.2016.26
• Languages: English
• ISSNs: 0272-9172

Abstract

ABSTRACT: Amorphous silicon (α-Si) was deposited on glass substrates by PECVD at different deposition conditions in order to characterize the residual stress on the film. Subsequently, a thermal-annealing was applied for different times at 400 °C in a N2 atmosphere, aiming to reduce the stress in the films. The deposition power was between 15 and 30 W at 13.56 MHz, the pressure in the chamber was adjusted in a range from 600 to 900 mTorr, and the temperature was varied from 140 to 200 °C. The stress was determined by using the Stoney equation, measuring the curvature and thickness of the α-Si films with a stylus profilometer. A deposition rate between 7-24 nm/min was obtained, and the time for thermal-annealing needed to reduce the stress was reduced from 10 to 2-4 h, obtaining a minimum compressive stress of 17 MPa. With this value of stress, it was possible to use the α-Si as masking material for wet etching of glass during the manufacturing of microfluidic devices, in order to obtain microstructures in the glass with 150 μm in depth.