Raised source/drains for 50nm MOSFETs using a silane/dichlorosilane mixture for selective epitaxy

The silicon epitaxial growth behaviour was studied as an application of the parallel-Langmuir process using SiH2Cl2 gas and SiH3CH3 gas. The SiH3CH3 gas was used for in situ producing the SiHx gas by thermal decomposition in the reactor. With the increasing gas concentration of SiH3CH3, several results were obtained, such as (i) the silicon epitaxial growth rate increased exceeding the value saturated using the SiH2Cl2, (ii) the gas phase concentrations of the chlorosilanes at the exhaust decreased, (iii) the byproduct deposition at the exhaust decreased, and (iv) the gas phase concentration of HCl at the exhaust decreased. As a conclusion, the SiHx helped consuming the SiH2Cl2 gas for producing a silicon epitaxial film with reducing the byproduct deposition. Additionally, the SiHx might produce SiH2Cl2 in the gas phase by the reaction with the HCl gas.

Section: Rate Theorymentioning

confidence: 99%

Section: Rate Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Silicon epitaxial growth accelerated by parallel Langmuir processes using SiH₂Cl₂ and SiH₃CH₃ gases

Yamada¹,

Muroi²,

Watanabe³

et al. 2018

“…Lower values of the DIBL indicate better control of the channel by the applied gate bias, which can be achieved by optimization techniques such as increased channel doping [24], elevated source-drain [25], thin silicon-body [26] and thin buried-oxide [27] of the SOI film, together with the implementation of multiple-gate architecture [28,29]. An increase in DIBL occurs in devices where the gate length is scaled without proper scaling of other dimensions.…”

Section: Drain-induced Barrier Loweringmentioning

confidence: 99%

Review on analog/radio frequency performance of advanced silicon MOSFETs

Passi

Raskin

2017

Aggressive gate-length downscaling of the metal-oxide-semiconductor field-effect transistor (MOSFET) has been the main stimulus for the growth of the integrated circuit industry. This downscaling, which has proved beneficial to digital circuits, is primarily the result of the need for improved circuit performance and cost reduction and has resulted in tremendous reduction of the carrier transit time across the channel, thereby resulting in very high cut-off frequencies. It is only in recent decades that complementary metal-oxide-semiconductor (CMOS) field-effect transistor (FET) has been considered as the radio frequency (RF) technology of choice. In this review, the status of the digital, analog and RF figures of merit (FoM) of silicon-based FETs is presented. State-of-the-art devices with very good performance showing low values of draininduced barrier lowering, sub-threshold swing, high values of gate transconductance, Early voltage, cut-off frequencies, and low minimum noise figure, and good low-frequency noise characteristic values are reported. The dependence of these FoM on the device gate length is also shown, helping the readers to understand the trends and challenges faced by shorter CMOS nodes. Device performance boosters including silicon-on-insulator substrates, multiple-gate architectures, strain engineering, ultra-thin body and buried-oxide and also III-V and 2D materials are discussed, highlighting the transistor characteristics that are influenced by these boosters. A brief comparison of the two main contenders in continuing Moore's law, ultra-thin body buried-oxide and fin field-effect transistors are also presented. The authors would like to mention that despite extensive research carried out in the semiconductor industry, silicon-based MOSFET will continue to be the driving force in the foreseeable future.Keywords: analog and radio-frequency figures of merit, digital figures of merit, multiple gate field effect transistor, ultra-thin body buried-oxide, III-V and two-dimensional channel field effect transistor

“…A mixture of silane and dichlorosilane was used in [3] to deposit at 750 °C Si raised sources and drains on each side of metal-oxide semiconductor field effect transistors. Facet-free selective epitaxy (to silicon nitride) was achieved without any requirements for Cl 2 or HCl in the gas stream.…”

Section: Introductionmentioning

confidence: 99%

Impact of Si precursor mixing on the low temperature growth kinetics of Si and SiGe

Hartmann

2018

I have quantified, in a 300 mm ASM Epsilon 3200 tool, the impact of adding SiH 4 or SiH 2 Cl 2 to Si 2 H 6 on the low temperature growth kinetics of Si and SiGe. Increasing the amount of Si atoms by adding the formers to the latter resulted in Si growth rates (GR) reductions (i) at 20 Torr, in the 500 °C-575 °C range and (ii) at 525 °C, in the 20-90 Torr range. Those GR decreases were more pronounced with SiH 2 Cl 2 than with SiH 4 . I have otherwise investigated the 525 °C, 20 Torr growth kinetics of SiGe with germane (GeH 4 ) as the Ge source and various mixes of Si precursors. The GR associated with a SiH 2 Cl 2 +GeH 4 chemistry was lower than the Si 2 H 6 +SiH 2 Cl 2 +GeH 4 GR, which was itself lower than the Si 2 H 6 +GeH 4 one. Meanwhile, the Ge content was much higher with SiH 2 Cl 2 +GeH 4 than with Si 2 H 6 +SiH 2 Cl 2 +GeH 4 . The later was itself ∼1% to ∼4% higher than the Si 2 H 6 +GeH 4 one depending on the GeH 4 flow. As for pure Si, Si 2 H 6 governed the SiGe growth kinetics, with SiH 2 Cl 2 acting as if it was a source of HCl (GR reduction and slight Ge content increase). The situation was more complex when adding SiH 4 to Si 2 H 6 +GeH 4 . The Si 2 H 6 +SiH 4 +GeH 4 GR was always lower than the Si 2 H 6 +GeH 4 one. Meanwhile, the SiH 4 +GeH 4 GR was either lower or higher than the other two depending on the GeH 4 flow. The Ge content was significantly higher with SiH 4 +GeH 4 than with Si 2 H 6 +SiH 4 +GeH 4 (27%-53% range ⇔ 9%-32% range). The latter was itself ∼2% lower than the Si 2 H 6 +GeH 4 one. As before, Si 2 H 6 governed the SiGe growth kinetics, with SiH 4 slightly reducing both the GR and the Ge content, which is unusual. Plotting the SiGe GR as functions of the Ge concentration showed that the addition of SiH 4 or SiH 2 Cl 2 molecules did not dramatically change the SiGe growth kinetics, which was predominantly governed at 525 °C, 20 Torr by Si 2 H 6 .