Invited Paper PS2-ThA1
High Quality Thin Films Deposited at Low Temperatures by Plasma Enhanced ALD and CVD Techniques

Thursday, October 23, 2008, 2:00 pm, Room 306

Low temperature deposition of thin films is becoming increasingly important with a growing range of low thermal budget materials being used in device research. The rapid development and predicted future market for plastic electronics has resulted in a greatly increased focus on thin film depositions below 150ºC. This contribution will address the challenges of low temperature deposition in the context of some example applications including; depositing directly onto photo-resist for lift-off, Si₃N₄ MIM capacitor technology for MMIC and RF-MEMs¹ and Al₂O₃ moisture permeation barriers for polymer based devices such as flexible OLEDs.² The study will focus on two chemical vapour deposition (CVD) techniques ideally suited for low temperature deposition namely; Inductively Coupled Plasma CVD and Remote Plasma Atomic Layer Deposition. For any thin film CVD process it is widely true that film quality will degrade at lower temperatures. This degradation is most often measured by decreasing film density, refractive index, breakdown voltage and adhesion; and increasing film impurities and wet etch rates. By using the energetic and reactive plasma species to replace thermal energy it is possible to deposit films with acceptable quality at room temperature, i.e. 25ºC. By generating the plasma remotely such improved film quality can be achieved with low plasma damage to the substrate.

¹Low temperature high density Si₃N₄ MIM capacitor technology for MMMIC and RF-MEMs applications. K. Elgaid, H. Zhou, C. D. W. Wilkinson and I. G. Thayne, Microelectronic Engineering, Volumes 73-74, June 2004, Pages 452-455
²Plasma-assisted atomic layer deposition of Al₂O₃ moisture permeation barriers on polymers. E. Langereis, M. Creatore, S.B.S. Heil, M.C.M. van de Sanden, and W.M.M. Kessels, Appl. Phys. Lett. 89, 081915 (2006).