Effects of Fluorine Plasma Treatment on the Electronic Structure of Plasma-Enhanced Atomic Layer Deposition HfO[sub 2]

Abstract

We investigated the effects of fluorine treatments on the electrical properties and electronic structures of plasma-enhanced atomic layer deposition HfO 2 gate oxides, depending on the treatment process. Pre-and postoxide-deposition fluorine treatments were carried out using CF 4 plasma. Improved dielectric properties were achieved by predeposition treatment, while degradation of electrical properties was observed for postdeposition treatment. Based on the electronic structure analysis using X-ray photoemission spectroscopy and near-edge X-ray absorption fine structures, we found that the enhanced dielectric properties of the pretreated HfO 2 are induced by the defect passivation and conduction-band offset increase.

Passivation of oxide traps in gallium arsenide (semiconductor) metal-oxide-semiconductor capacitor with high-k dielectric by using fluorine incorporation

“…3(a), which supports that fluorine incorporation in the high-k dielectric is effective only for the plasma treatment after the deposition of the high-k dielectric, basically consistent with the result in Ref. 23. The not-so clear F 1s peak of the Pre-F sample indicates less F incorporated at/near the high-k/GaAs interface and thus less passivation of dangling bonds there, leading to larger D it than that of the Post-F sample as supported by the data in Table I.…”

“…The Pre-F sample shows the largest leakage current (7.04 Â 10 À4 A/cm 2 at gate voltage of 1 V) probably because the predeposition F treatment induces radiationrelated damage to the GaAs surface and also results in excess F interstitials at the interface in the form of gap states. 17,23 In order to clarify the effects of the fluorine treatment, the chemical states in the dielectric layer and at/near the high-k/GaAs interface after the whole fabrication process are analyzed by XPS. Figure 2 shows the XPS spectrum for Ta 4f.…”

Plasma-Assisted Atomic Layer Deposition: Basics, Opportunities, and Challenges

“…Plasmas can be used for substrate pretreatment (e.g. oxidation by an O 2 plasma 69,70,119,122,130,132,149 and nitridation by NH 3 or N 2 plasmas 119,129,132 ), substrate cleaning, 98 post-deposition treatments, 141,164 and reactor wall conditioning and cleaning. 240 For example, a layer of TiN covering the walls of the reactor can be removed easily by running a F-based plasma such as one generated in NF 3 or SF 6 .…”

“…122,130,132 The use of a CF 4 plasma for 60 s was also proven to be beneficial prior to the deposition process. 141 Maeng et al reported interface defect passivation by Si-F bonds resulting in a decrease in the flatband voltage and a lower leakage current density. The deposition of HfO 2 on a 1.0 nm thick plasma-nitrided HfO 2 or Al 2 O 3 layer was found to result in a thinner interfacial layer, a lower EOT, a lower leakage current density, and a reduced charge defect density.…”

Flatband voltage control in p-metal gate metal-oxide-semiconductor field effect transistor by insertion of TiO2 layer

“…The extraction of capacitance equivalent thickness ͑CET͒ values and interface state density ͑D it ͒ is described in our previous reports. 12,13 Figure 1͑a͒ shows XPS spectra in Al 2p binding energy region for as-deposited and HTA ͑T a = 800°C͒ HfO 2 samples with Al 2 O 3 top layer ͑Si/ HfO 2 / Al 2 O 3 ͒. For both samples, Al 2p peak is observed clearly at 75 eV, indicating the presence of Al 2 O 3 top layer.…”