AVS 53rd International Symposium
    Thin Film Tuesday Sessions
       Session TF+SS-TuA

Invited Paper TF+SS-TuA1
Surface Functionalization for Selective Area ALD

Tuesday, November 14, 2006, 2:00 pm, Room 2022

Session: Surface Functionalization for Selective Area ALD
Presenter: S.F. Bent, Stanford University
Authors: R. Chen, Stanford University
J. Hong, Stanford University
S.F. Bent, Stanford University
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Atomic layer deposition (ALD) is a powerful ultra-thin film deposition method for preparing a variety of materials. Typically, the process permits nano-scale control of materials in the vertical direction. To develop the method for three-dimensional control of materials, we have been investigating an area-selective ALD technique which will enable micro- and ultimately nano-scale definition of the lateral structure. Our approach is to chemically modify the substrate surface in order to impart spatial selectivity to ALD. Our focus is on both oxide materials (e.g. HfO@sub 2@ and ZrO@sub 2@) and metals (e.g. Pt) deposited by ALD. We have investigated several different types of self-assembled monolayers (SAMs) as resists against ALD using both solution and vapor delivery methods. Oxide-coated substrates (e.g. SiO@sub 2@) have been protected using organosilane-based SAMs, and hydrogen-terminated Si and hydrogen-terminated Ge protected by reaction with alkenes or alkynes. We have followed the SAM properties as a function of molecular structure and formation time using a variety of experimental techniques and have correlated the properties of the SAMs with their efficacy as ALD resists. With the successful ALD resists, area-selective ALD has been carried out using different patterning methods to define the lateral structure. Both microcontact printing of the SAMs and selective functionalization of a SiO@sub 2@/Si structure have been used to achieve area-selective ALD. We have compared the selectivity between the two methods, and will discuss the differences in the context of the SAM resist requirements. We will also show that by choosing either silylation- or hydrosilylation-based chemical functionalization, a single patterned oxide substrate can be used for either positive or negative pattern transfer into the ALD film.