Growth and electrical properties of atomic-layer deposited ZrO2/Si-nitride stack gate dielectrics

Abstract

Articles you may be interested inStructural and dielectric properties of thin ZrO 2 films on silicon grown by atomic layer deposition from cyclopentadienyl precursor Characterization of atomic-layer-deposited silicon nitride / SiO 2 stacked gate dielectrics for highly reliable pmetal-oxide-semiconductor field-effect transistors Atomic-layer-deposited silicon-nitride/SiO 2 stacked gate dielectrics for highly reliable pmetal-oxide-semiconductor field-effect transistorsWe deposited ZrO 2 thin films by atomic-layer deposition ͑ALD͒ using zirconium tertiary-butoxide ͓Zr(t-OC 4 H 9 ) 4 , ͑ZTB͔͒ and H 2 O source gases on Si substrates at low temperatures. We grew ZrO 2 films layer by layer in a temperature range of 175-250°C to minimize surface roughness. The deposited ZrO 2 film thickness had self-limiting properties with the exposure time of ZTB and vapor pressures of ZTB and H 2 O. The deposition rate per cycle was independent of the vapor pressure of ZTB from 0.01 kPa to 0.04 kPa. Transmission electron microscopy revealed that the formation of an SiO x interfacial layer could be suppressed by using an ALD ZrO 2 /ALD Si-nitride ͑ϳ0.5 nm͒ stack structure. We found the fixed charge, interface trap density, and leakage current density in the ALD ZrO 2 /ALD Si-nitride stack dielectrics to be less than those in ALD ZrO 2 dielectrics. In spite of the same equivalent oxide thickness of 1.6 nm, the relative dielectric constant r ͑11.5͒ of the ALD ZrO 2 /ALD Si-nitride stack capacitor was higher than that ͑10.5͒ of the ALD ZrO 2 capacitor due to the suppression of formation of the interfacial SiO x layer ͑1.0-1.5 nm͒ by an ultrathin ALD Si nitride ͑ϳ0.5 nm͒. The current conduction mechanism is identified as direct tunneling of electron except at very low dielectric fields. Comparing structural and electrical properties, ALD ZrO 2 /ALD Si-nitride stack dielectrics are promising candidates for sub-0.1-m metal-oxide-semiconductor field-effect transistors.

Characteristics of ZrO2 gate dielectrics on O2- and N2O-plasma treated partially strain-compensated Si0.69Ge0.3C0.01 layers

“…The magnitudes are comparable to the other reported results of ZrO 2 dielectrics on nitrided Si. 28,29 From the accumulation capacitances, the effective dielectric constants ͑ eff ͒ are found to be ϳ12 and ϳ14 for ZrO 2 /O 2 -treated SiGeC and ZrO 2 /N 2 O-treated SiGeC structures, respectively. Taking account the value of dielectric constant ͑ hk ͒ of ZrO 2 as 17.5, 9 the dielectric constant ͑ IL ͒ of interfacial layer is calculated using the series capacitance analysis ͑Fig.…”

Influence of pre-deposition treatments on the interfacial and electrical characteristics of ZrO2 gate dielectrics

“…Besides, incorporation of nitrogen into the IL is another possible solution. Ishii et al [7] deposited ZrO 2 films by atomic layer deposition, and the growth of the IL was suppressed in the presence of a 0.5 nm Si-nitride barrier layer. Maikap et al [8] revealed that N 2 O/NH 3 plasma oxynitrided IL enhanced the electrical properties of HfO 2 as compared to bare silicon.…”

Effects of oxidation and nitridation temperatures on electrical properties of sputtered Zr thin film based on Si in N2O ambient

“…The nitrided ZrO 2 thin film may suppress the outdiffusion of Si by passivating its dangling bonds located on the surface and may improve the hot carrier resistance at the Si-dielectric interface. [13][14][15] According to several reports, [15][16][17] the presence of nitrogen has resulted in a better electrical characteristic of MOS structure with ZrO 2 thin films as the gate oxide. In order to perform oxidation and nitridation simultaneously, NO and N 2 O are the typical gases being used.…”