The Effect of Surface Treatments and Growth Conditions on Electrical Characteristics of Thick (&gt;50 nm) Gate Oxides

Wu, C. T.; Ridley, R.S.; Román, Pascual; Dolny, G.; Grebs, T.; Hao, Jilong; Rużyłło, Jerzy

doi:10.1149/1.1390347

Cited by 8 publications

(6 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Positive stress 15 Additionally, it has been proven that higher oxidation temperature resulted in better GOI due to more relaxation of Si-SiO 2 bonds. [6][7][8][9] In summary, the GOI improvement of 1175°C Ar/O 2 oxidation over 1100°C N 2 /O 2 oxidation is a combined effect of an absence of nitrogen atoms at the Si -SiO 2 interface and higher oxidation temperature.…”

Section: Negative Stressmentioning

confidence: 94%

“…High-temperature gate oxidation gained interest for processing thick gate oxides when it was proven that it could improve GOI by relaxing of Si-SiO 2 interface stress [6][7][8][9] and decreasing the oxidation time. However, during high-temperature oxidation, nitrogen gas becomes a concern.…”

mentioning

confidence: 99%

“…[11][12][13][14] The effect of oxidation temperature and carrier gas has been investigated and reported elsewhere. 9,15 Another key element of UMOSFET is the formation of a U-shaped channel, or trench. Due to its anisotropic nature, reactive ion etching ͑RIE͒ is used to perform the trench etching.…”

mentioning

confidence: 99%

See 2 more Smart Citations

The Effects of Hydrogen Annealing on Gate Oxide Integrity of U-Shaped Trench MOSFET with 400 Å Gate Oxide

Sharp

Madson

et al. 2006

J. Electrochem. Soc.

View full text Add to dashboard Cite

The effects of hydrogen ͑H 2 ͒ annealing on the thick gate oxide integrity of the U-shaped trench metal-oxide-semiconductor-field effect transistor ͑UMOSFET͒ were investigated. H 2 annealing was performed after trench etch and before gate oxidation. It was observed that the gate oxide integrity ͑GOI͒ of the 400 Å gate oxide grown after H 2 annealing can be comparable to the standard approach ͑soft etch and sacrificial oxidation͒ when the trench width is kept at 0.65 m. When the trench width was reduced to 0.45 m the GOI of H 2 annealing samples was degraded slightly due to faceting at the transition region between trench sidewall and bottom. It was proven that using high-temperature gate oxidation, the UMOSFET with 0.45 m trench width and H 2 annealing has very high-quality gate oxide. The reduction of process steps and time and the potential for narrower trench make H 2 annealing an attractive process in trench MOSFET processing.

show abstract

Section: Negative Stressmentioning

confidence: 94%

mentioning

confidence: 99%

See 1 more Smart Citation

The Effects of Hydrogen Annealing on Gate Oxide Integrity of U-Shaped Trench MOSFET with 400 Å Gate Oxide

Sharp

Madson

et al. 2006

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…The Si surface was cleaned by a modified RCA clean and dipped in 1% HF solution before deposition [9]. The sputtering chamber was pumped down to 5 × 10 − 4 Pa. By radio-frequency (rf) magnetron sputtering from a Zr target (purity: 99.7%), the Zr metal layer was deposited in Ar ambient, and the ZrO 2 layer was deposited in an Ar/O 2 mixture.…”

Section: Methodsmentioning

confidence: 99%

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

2007

View full text Add to dashboard Cite

“…Hightemperature gate oxidation gained interest for processing thick gate oxides, because it has been proven that it can improve gate oxide integrity ͑GOI͒ due to the relaxation of Si-SiO 2 interface stress. [4][5][6][7] Moreover, it decreases the oxidation time.…”

mentioning

confidence: 99%

The Effect of Carrier Gas in Gate Oxidation on the Gate Oxide Integrity of Thick Gate Oxide for UMOSFETs

Woolsey

Madson

et al. 2005

J. Electrochem. Soc.

View full text Add to dashboard Cite

The effect of carrier gas on the gate oxide integrity ͑GOI͒ of thick gate oxide ͑400 Å͒ for U-trench metal-oxide-semiconductor field-effect transistors UMOSFETs was investigated. Ar or N 2 were selected as the carrier gases during gate oxidation, and X-ray photoelectron spectroscopy was used to identify the nitrogen depth profile. It was observed that GOI of the 400 Å gate oxide grown at 1175°C can be improved by using Ar as the carrier gas instead of N 2 due to the fact that N 2 interacts with the Si surface during high-temperature oxidation.Power metal-oxide-semiconductor field-effect transistors ͑MOSFETs͒ have been widely used in applications such as automatic electronics, wireless communication, desktop, and laptop computers. One of the most popular device structures for low and medium power application is UMOSFET, 1-3 in which a U-shaped trench is etched in the Si substrate and the source and drain are located at opposite sides of the wafer. This vertical structure allows higher current capability, higher package density, and lower onresistance.Power MOSFETs require much thicker gate oxides ͑e.g., 400 Å͒ than submicrometer geometry MOS devices which feature ultrathin gate oxides ͑Ͻ30 Å͒ due to high voltage/power rating. Hightemperature gate oxidation gained interest for processing thick gate oxides, because it has been proven that it can improve gate oxide integrity ͑GOI͒ due to the relaxation of Si-SiO 2 interface stress. 4-7 Moreover, it decreases the oxidation time.Nitrogen gas is the most frequently used carrier gas in semiconductor industry during device processing. However, N 2 interacts with the Si surface at 980-1200°C. 8 Heat treatment of silicon wafers in nitrogen at high-temperature ambient ͑1200°C, 1 h͒ resulted in haziness of the surface, due to the formation of stacking fault nuclei. 9 It was observed that the interaction of N 2 at the Si surface would increase defect density and reduce the dielectric strength of the gate oxide in the range of 70 to 600 Å on planar surfaces. [10][11][12] In this work, the effect of N 2 and Ar carrier gas on the gate oxide integrity of a 400 Å gate oxide, which was grown on the trench surface, was investigated and compared. It is the first attempt to evaluate the GOI of a UMOSFET by comparing Ar with N 2 as the gate oxidation carrier gas. ExperimentalFor X-ray photoelectron spectroscopy ͑XPS͒ measurement, a trench capacitor-like structure was used. Three 150 mm diameter, n-type, ͑100͒ heavily doped Si wafers were used in this experiment. 5 m of lightly doped n-type Si ͑n-Si͒ was grown on the top of the substrate by epitaxy, and the experimental splits are shown in Table I. The trench was etched by reactive ion etching ͑RIE͒ and followed by gate oxidation, and the oxidation time was adjusted to achieve a target thickness of 400 Å for all splits. The location for XPS analysis was carried out at the BPSG mesa between trenches. The instrument settings were as follows: monochromated Al K␣ at 1486.6 eV was used as the X-ray source, with an acceptance angle of ±23°, a...

show abstract

The Effect of Surface Treatments and Growth Conditions on Electrical Characteristics of Thick (>50 nm) Gate Oxides

Cited by 8 publications

References 7 publications

The Effects of Hydrogen Annealing on Gate Oxide Integrity of U-Shaped Trench MOSFET with 400 Å Gate Oxide

The Effects of Hydrogen Annealing on Gate Oxide Integrity of U-Shaped Trench MOSFET with 400 Å Gate Oxide

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

The Effect of Carrier Gas in Gate Oxidation on the Gate Oxide Integrity of Thick Gate Oxide for UMOSFETs

Contact Info

Product

Resources

About