Fabrication of high Ge content SiGe layer on Si by Ge condensation technique

Balakumar, S.; Wei, Tan; Tung, Chih-Hang; Lo, Guo‐Qiang; Nguyen, H. S.; Fong, Chien-Fu; Agarwal, Ajay; Kumar, R.; Balasubramanian, N.; Lee, S; Kwong, D. L.

doi:10.1109/ipfa.2006.251050

Cited by 6 publications

(5 citation statements)

References 12 publications

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“…The change in the sensitivity of the plasma-treated nanowire is opposite that of the bare nanowire in the temperature region 800∼950 ∘ C. At 1000 ∘ C, the sensitivity of the bare nanowire sample decreases. According to the literature, temperature has an important effect on the SGOI structure [41][42][43]. It is observed that the raise of the sensitivity of "bare" SiGe nanowire is more obvious at temperature of 950 ∘ C due to better concentration and enough energy to recrystallize.…”

Section: Resultsmentioning

confidence: 99%

Self-Passivation by Fluorine Plasma Treatment and Low-Temperature Annealing in SiGe Nanowires for Biochemical Sensors

Chang

Lai

Chen

et al. 2014

Journal of Nanoscience

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Nanowires are widely used as highly sensitive sensors for electrical detection of biological and chemical species. Modifying the band structure of strained-Si metal-oxide-semiconductor field-effect transistors by applying the in-plane tensile strain reportedly improves electron and hole mobility. The oxidation-induced Ge condensation increases the Ge fraction in a SiGe-on-insulator (SGOI) and substantially increases hole mobility. However, oxidation increases the number of surface states, resulting in hole mobility degradation. In this work, 3-aminopropyltrimethoxysilane (APTMS) was used as a biochemical reagent. The hydroxyl molecule on the oxide surface was replaced by the methoxy groups of the APTMS molecule. We proposed a surface plasma treatment to improve the electrical properties of SiGe nanowires. Fluorine plasma treatment can result in enhanced rates of thermal oxidation and speed up the formation of a self-passivation oxide layer. Like a capping oxide layer, the self-passivation oxide layer reduces the rate of follow-up oxidation. Preoxidation treatment also improved the sensitivity of SiGe nanowires because the Si-F binding was held at a more stable interface state compared to bare nanowire on the SiGe surface. Additionally, the sensitivity can be further improved by either the N2 plasma posttreatment or the low-temperature postannealing due to the suppression of outdiffusion of Ge and F atoms from the SiGe nanowire surface.

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Section: Resultsmentioning

confidence: 99%

Self-Passivation by Fluorine Plasma Treatment and Low-Temperature Annealing in SiGe Nanowires for Biochemical Sensors

Chang

Lai

Chen

et al. 2014

Journal of Nanoscience

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“…According to the literature, temperature has important effects on SGOI structure [22,24]. A suitable thermal budge can re-crystallize the interface between the oxide and SiGe, reducing the number of dislocations and interior defects.…”

Section: Resultsmentioning

confidence: 99%

“…Like dislocations and interstitials, surface defects that are formed by oxidation and strain can cause lattice mismatches between oxide and SiGe layer that can affect carrier mobility in the sensor device. Accordingly, an improved understanding of the characteristics that are produced by Ge condensation [24,25] is needed to optimize and improve biosensor sensitivity. In this work, ambient oxidation, oxidation time and nano-wire structure were varied while the oxidation temperature was fixed at 950°C to prevent the undesirable consequences of an inappropriately low or high temperature during Ge condensation.…”

Section: Introductionmentioning

confidence: 99%

Oxidation study of Ge Condensation on SGOI Nanowire Biosensor Fabrication

et al. 2013

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The Ge condensation method is effective in increasing the Ge fraction of Ge in SGOI. Previous studies by the authors confirmed a correlation between the Ge fraction and the sensitivity of the SiGe nano-wire sensor. To understand how Ge condensation on an SGOI nano-wire sensor helps to optimize oxidation conditions and sensitivity, the effect of oxidizing gas and the SiGe/α-Si stacked structure on the movement of Ge is investigated. The analytical results reveal that the sensitivity of SiGe nano-wires can be optimized by stacking an Si1-xGex layer that contains 14% Ge on a 200 Å-thick α-Si layer and treating the stack with O2 gas diluted by 13% N2 for 3 min.

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“…From the above discussion, the conductance and sensitivity can be improved by forming a stacked structure, which makes carriers pass through the surface with higher conductivity and increasing the surface-to-volume ratio, further causing the condensation of the carriers. According to the research [22,23,24], Ge condensation can increase the fraction of Ge at the surface, causing the rejection of Ge from the SiO 2 upon oxidation. Figure 9 presents the results of using three ambient treatments-in pure N 2 , pure O 2 and O 2 mixed with 13.33% N 2 .…”

Section: Resultsmentioning

confidence: 99%

The α-Si/SiGe Core/Shell Nano-Wire as Highly Sensitive Bio-Sensor

Chang¹,

Chen²,

Lai

et al. 2011

ECS Trans.

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Reducing the width of a nano-wire increases its surface to volume ratio, increasing the sensitivity of its conductivity to charges on its surface. Our previous studies have shown that increasing the Ge fraction in Si1-xGex nano-wires improves their sensitivity as bio-sensing. In this work, an α-Si/SiGe core/shell nano-wire is successfully fabricated using side-wall spacer method. The maximum sensitivity of a nano-wire bio-sensor with an optimizedα-Si/SiGe thickness ratio is investigated.

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Fabrication of high Ge content SiGe layer on Si by Ge condensation technique

Cited by 6 publications

References 12 publications

Self-Passivation by Fluorine Plasma Treatment and Low-Temperature Annealing in SiGe Nanowires for Biochemical Sensors

Self-Passivation by Fluorine Plasma Treatment and Low-Temperature Annealing in SiGe Nanowires for Biochemical Sensors

Oxidation study of Ge Condensation on SGOI Nanowire Biosensor Fabrication

The α-Si/SiGe Core/Shell Nano-Wire as Highly Sensitive Bio-Sensor

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