Analysis of border and interfacial traps in ALD-Y2O3 and -Al2O3 on GaAs via electrical responses - A comparative study

Atomic Nature of the Growth Mechanism of Atomic Layer Deposited High-κ Y2O3 on GaAs(001)-4 × 6 Based on in Situ Synchrotron Radiation Photoelectron Spectroscopy

“…It is noted that the Ga 2 O (Ga + )-like state, Ga*, does not result in the gap state. 23−26 The absence of the interface defect state from the Ga 2 O 3 (Ga 3+ )-like gap state (20.70 eV) 22 explains well the low D it (<10 12 cm –2 eV –1 ) in our previous study (ref (7)). 24,25…”

“…In a separate experiment on an annealed ALD-Y 2 O 3 (8 cycles)/GaAs(001)-4 × 6, as shown in Figure , heat immediately wipes off the As* component, suggesting that it could not be associated with the interfacial bonding state, but rather with the freed As in the oxide overlayer. It is noted that the Ga 2 O (Ga + )-like state, Ga*, does not result in the gap state. − The absence of the interface defect state from the Ga 2 O 3 (Ga 3+ )-like gap state (20.70 eV) explains well the low D it (<10 12 cm –2 eV –1 ) in our previous study (ref ). , …”

“…5,6 Moreover, the interfacial trap density ( D it ) is low (<10 12 cm –2 eV –1 ), and the D it distribution within the GaAs band gap is flat without a peak bulge in the midgap. 7 A similar 3 + oxide, such as Al 2 O 3 , fails to return with such excellent electric performances. 8−13 In situ synchrotron radiation photoelectron spectroscopy (SRPES) was used to study the interfacial electronic structure of the film in sub-ML thickness to bulk.…”

“…We specifically selected the system of ALD-Y 2 O 3 on freshly molecular beam epitaxy (MBE)-grown pristine GaAs(001)-4 × 6 because the oxide film orients itself along the surface normal (110), which shows a single-domain single-crystalline cubic phase. , Moreover, the interfacial trap density ( D it ) is low (<10 12 cm –2 eV –1 ), and the D it distribution within the GaAs band gap is flat without a peak bulge in the midgap . A similar 3 + oxide, such as Al 2 O 3 , fails to return with such excellent electric performances. − In situ synchrotron radiation photoelectron spectroscopy (SRPES) was used to study the interfacial electronic structure of the film in sub-ML thickness to bulk.…”

Scavenging Segregated Ge on Thin Single-Crystal Si Epitaxially Grown on Ge

“…The corresponding C−V characteristics for the two samples measured at room temperature under different frequencies ranging from 1 MHz to 500 Hz are plotted in the insets of the left and right panels in Figure 5. The small frequency dispersion in the depletion regions of both samples suggests attainment of a low D it value at the high-κ/Si/Ge interface, 33 and the D it has not degraded after the scavenging cycles.…”