Metal gate-HfO2 metal-oxide-semiconductor capacitors on n-GaAs substrate with silicon/germanium interfacial passivation layers

Kim, Hyoung Sub; Ok, I.; Zhang, Manhong; Lee, Tackhwi; Zhu, Feng; Lan, Yu; Lee, Jack C.

doi:10.1063/1.2396912

Cited by 59 publications

(40 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These efforts are summarized in a review paper. 14 On the other hand, attempts to control GaAs and InGaAs surfaces by Si ICL and Si/ Ge ICL have also been made by other groups such as Morkoç and co-workers [15][16][17] and, more recently, Lee and co-workers 18,19 in order to realize high performance GaAs MOS transistors.…”

Section: Introductionmentioning

confidence: 99%

Formation of ultrathin SiNx∕Si interface control double layer on (001) and (111) GaAs surfaces for ex situ deposition of high-k dielectrics

Akazawa

Hasegawa

2007

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

View full text Add to dashboard Cite

In order to realize pinning-free high-k dielectric metal-insulator-semiconductor ͑MIS͒ gate stack on ͑001͒ and ͑111͒B oriented GaAs surfaces using the Si interface control layer ͑Si ICL͒ concept, formation of a SiN x / Si ICL double layer was investigated as a chemically stable structure on ͑001͒ and ͑111͒B surfaces which allows ex situ deposition of HfO 2 high-k dielectric films without losing the benefit of Si ICL. First, Si ICLs grown by molecular beam epitaxy ͑MBE͒ on ͑001͒ and ͑111͒B GaAs surfaces with various initial surface reconstructions were investigated in detail by reflection high energy electron diffraction and x-ray photoelectron spectroscopy ͑XPS͒ investigations at each step of the interface formation. Large shifts of the surface Fermi level position toward unpinning were observed after Si ICL growth on appropriately formed Ga-stabilized surfaces. It was found that Si layers grow epitaxially with Si-Ga bonds at the Si/ GaAs interface and Si-As termination on top, suggesting surfactant roles played by As atoms. Then, an ultrathin SiN x buffer film was formed on the Si ICL by its in situ partial nitridation in the MBE chamber. An XPS analysis of the resultant SiN x / Si ICL double layer formed on ͑001͒ and ͑111͒B surface indicated that the structure is chemically stable against air exposure on both surfaces in the sense that it prevents the host GaAs surface from subcutaneous oxidation, although SiN x film itself partially turns into SiO x N y . Finally, high-k MIS capacitors were formed by ex situ deposition of HfO 2 on the SiN x / Si ICL/GaAs structure after transferring the sample through air. The capacitance-voltage ͑C-V͒ analysis indicated that the MIS interface is completely pinning-free with a minimum interface state density in the range of low 10 11 cm −2 eV −1 .

show abstract

Section: Introductionmentioning

confidence: 99%

Formation of ultrathin SiNx∕Si interface control double layer on (001) and (111) GaAs surfaces for ex situ deposition of high-k dielectrics

Akazawa

Hasegawa

2007

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

View full text Add to dashboard Cite

show abstract

“…This factor has been one of the main obstacles to the development of viable high-k/III-V devices, since a high interface state density ͑D it ͒ has a critical detrimental effect on device characteristics, and as such has motivated extensive research in trying to understand the cause of these defects, and on the passivation of the high-k/III-V interface in an attempt to reduce D it . [1][2][3][4][5][6][7] One of the more common ex situ passivation techniques involves the use of sulfur based chemicals such as ammonium sulphide ͑NH 4 ͒ 2 S. [8][9][10][11][12] Aqueous ͑NH 4 ͒ 2 S is widely used due to its' effectiveness at removing native oxides, and at improving the electrical characteristics of devices fabricated on ͑NH 4 ͒ 2 S treated surfaces. 5,6 In addition, passivation in ͑NH 4 ͒ 2 S solution is a relatively quick, cost-effective, and straight-forward process.…”

Section: Introductionmentioning

confidence: 99%

A systematic study of (NH4)2S passivation (22%, 10%, 5%, or 1%) on the interface properties of the Al2O3/In0.53Ga0.47As/InP system for n-type and p-type In0.53Ga0.47As epitaxial layers

O’Connor

Brennan

Djara

et al. 2011

Journal of Applied Physics

123

View full text Add to dashboard Cite

In this work, we present the results of an investigation into the effectiveness of varying ammonium sulphide (NH4)2S concentrations in the passivation of n-type and p-type In0.53Ga0.47As. Samples were degreased and immersed in aqueous (NH4)2S solutions of concentrations 22%, 10%, 5%, or 1% for 20 min at 295 K, immediately prior to atomic layer deposition of Al2O3. Multi-frequency capacitance-voltage (C-V) results on capacitor structures indicate that the lowest frequency dispersion over the bias range examined occurs for n-type and p-type devices treated with the 10%(NH4)2S solution. The deleterious effect on device behavior of increased ambient exposure time after removal from 10%(NH4)2S solution is also presented. Estimations of the interface state defect density (Dit) for the optimum 10%(NH4)2S passivated In0.53Ga0.47As devices extracted using an approximation to the conductance method, and also extracted using the temperature-modified high-low frequency C-V method, indicate that the same defect is present over n-type and p-type devices having an integrated Dit of ∼2.5×1012 cm−2 (±1×1012 cm−2) with the peak density positioned in the middle of the In0.53Ga0.47As band gap at approximately 0.37 eV (±0.03 eV) from the valence band edge. Both methods used for extracting Dit show very good agreement, providing evidence to support that the conductance method can be applied to devices incorporating high-k oxides on In0.53Ga0.47As.

show abstract

“…[12][13][14] Although several attempts [9][10][11]15 applied sulfur treatment as a GaAs surface preparations and improved electrical performance for ALD high-k on III-V MOS devices was reported, the bonding arrangement at the sulfide passivated interface with deposited high-k dielectrics has still not been clearly revealed.…”

mentioning

confidence: 99%

Hf O 2 gate dielectric on (NH4)2S passivated (100) GaAs grown by atomic layer deposition

Chen

Sun

Kim

et al. 2008

Journal of Applied Physics

View full text Add to dashboard Cite

The interface between hafnium oxide grown by atomic layer deposition and (100) GaAs treated with HCl cleaning and (NH 4 ) 2 S passivation has been characterized.Synchrotron radiation photoemission core level spectra indicated successful removal of the native oxides and formation of passivating sulfides on the GaAs surface. Layer-bylayer removal of the hafnia film revealed a small amount of As 2 O 3 formed at the interface during the dielectric deposition. Traces of arsenic and sulfur out-diffusion into the hafnia film were observed after a 450 o C post-deposition anneal, and may be the origins for the electrically active defects. Transmission electron microscopy cross section images showed thicker HfO 2 films for a given precursor exposure on S-treated GaAs versus the SLAC-PUB-12802 September 2007Submitted to Journal of Applied Physics 2 non-treated sample. In addition, the valence-band and the conduction-band offsets at the HfO 2 /GaAs interface were deduced to be 3.18 eV and a range of 0.87-0.97 eV, respectively. It appears that HCl+(NH 4 ) 2 S treatments provide a superior chemical passivation for GaAs and initial surface for ALD deposition.

show abstract

Metal gate-HfO2 metal-oxide-semiconductor capacitors on n-GaAs substrate with silicon/germanium interfacial passivation layers

Cited by 59 publications

References 12 publications

Formation of ultrathin SiNx∕Si interface control double layer on (001) and (111) GaAs surfaces for ex situ deposition of high-k dielectrics

Formation of ultrathin SiNx∕Si interface control double layer on (001) and (111) GaAs surfaces for ex situ deposition of high-k dielectrics

A systematic study of (NH4)2S passivation (22%, 10%, 5%, or 1%) on the interface properties of the Al2O3/In0.53Ga0.47As/InP system for n-type and p-type In0.53Ga0.47As epitaxial layers

Hf O 2 gate dielectric on (NH4)2S passivated (100) GaAs grown by atomic layer deposition

Contact Info

Product

Resources

About