title: The influence of surface preparation on low temperature HfO2 ALD on InGaAs (001) and (110) surfaces.
abstract: Current logic devices rely on 3D architectures, such as the tri-gate field effect transistor (finFET), which utilize the (001) and (110) crystal faces simultaneously thus requiring passivation methods for the (110) face in order to ensure a pristine 3D surface prior to further processing. Scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy (XPS), and correlated electrical measurement on MOSCAPs were utilized to compare the effects of a previously developed in situ pre-atomic layer deposition (ALD) surface clean on the InGaAs (001) and (110) surfaces. Ex situ wet cleans are very effective on the (001) surface but not the (110) surface. Capacitance voltage indicated the (001) surface with no buffered oxide etch had a higher C(max) hypothesized to be a result of poor nucleation of HfO2 on the native oxide. An in situ pre-ALD surface clean employing both atomic H and trimethylaluminum (TMA) pre-pulsing, developed by Chobpattana et al. and Carter et al. for the (001) surface, was demonstrated to be effective on the (110) surface for producing low D(it) high C(ox) MOSCAPs. Including TMA in the pre-ALD surface clean resulted in reduction of the magnitude of the interface state capacitance. The XPS studies show the role of atomic H pre-pulsing is to remove both carbon and oxygen while STM shows the role of TMA pre-pulsing is to eliminate H induced etching. Devices fabricated at 120 °C and 300 °C were compared.
authors.affiliation: Materials Science and Engineering Department, University of California, San Diego, California 9500, USA.
authors.forename: Tyler
authors.initials: T
authors.lastname: Kent
authors.affiliation: Materials Science and Engineering Department, Stanford University, Stanford, California 94305, USA.
authors.forename: Kechao
authors.initials: K
authors.lastname: Tang
authors.affiliation: Materials Department, University of California, Santa Barbara, California 93106, USA.
authors.forename: Varistha
authors.initials: V
authors.lastname: Chobpattana
authors.affiliation: Materials Science and Engineering Department, Stanford University, Stanford, California 94305, USA.
authors.forename: Muhammad Adi
authors.initials: MA
authors.lastname: Negara
authors.affiliation: Materials Science and Engineering Department, University of California, San Diego, California 9500, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Edmonds
authors.affiliation: Materials Department, University of California, Santa Barbara, California 93106, USA.
authors.forename: William
authors.initials: W
authors.lastname: Mitchell
authors.affiliation: Global Foundries, 2600 Great America Way, Santa Clara, California 95054, USA.
authors.forename: Bhagawan
authors.initials: B
authors.lastname: Sahu
authors.affiliation: Global Foundries, 2600 Great America Way, Santa Clara, California 95054, USA.
authors.forename: Rohit
authors.initials: R
authors.lastname: Galatage
authors.affiliation: Department of Physics, Texas State University, San Marcos, Texas 78666, USA.
authors.forename: Ravi
authors.initials: R
authors.lastname: Droopad
authors.affiliation: Materials Science and Engineering Department, Stanford University, Stanford, California 94305, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: McIntyre
authors.affiliation: Materials Science and Engineering Department, University of California, San Diego, California 9500, USA.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Kummel