Comparison of KOH and TMAH Etching on Sinw Arrays Fabricated via AFM Lithography

Alias, Nurain Najihah; Yaacob, Khatijah Aisha; Yusoh, Siti Noorhaniah; Abdullah, Ahmad Makarimi

doi:10.1088/1742-6596/1082/1/012051

Cited by 8 publications

(6 citation statements)

References 7 publications

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“…For reducing the areal density of the SiNW array, etched SiNW templates were placed in 10 wt % aqueous KOH solution. 41 In our case as grown SiNW templates were dipped into KOH solution for 1, 2, and 5 min, respectively. Finally, all the samples were washed by DI water and dried under N 2 flow.…”

Section: Methodsmentioning

confidence: 99%

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Silicon Nanowire Arrays with Nitrogen-Doped Graphene Quantum Dots for Photodetectors

Mondal

Dey

Basori

2021

ACS Appl. Nano Mater.

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A significantly improved silicon nanowire (SiNW)based broadband photodetector is obtained in this work using the core−shell structure of SiNWs with hydrothermally processed nitrogen doped graphene quantum dots (N-GQDs). The performance of the photodetector device is enhanced significantly by enlarging the effective surface area of the SiNW/N-GQD heterostructure by controlled KOH etching of SiNWs. In combination with SiNWs, low-cost hydrothermal processed N-GQDs are used as a light absorber in the UV region and also as an emitter in the visible region which is reabsorbed by the SiNWs to enhance the device performance. The SiNW/N-GQD heterostructure photodetector exhibits a large photocurrent to dark-current ratio (∼0.8 × 10 2 under zero bias and as high as ∼0.5 × 10 4 under −2 V bias for 2 min KOH etching), remarkably low dark current (∼55 nA under −2 V bias for 2 min KOH etching and is six orders lower compared to control SiNWs device), and significantly improved external quantum efficiency (EQE) exceeding 150% in the near IR and ∼500% at 460 nm wavelength in the visible region. Such higher EQE may arise due to the (i) enhanced optical absorption, (ii) suppressed dark current, (iii) photomultiplication of charge carriers because of the presence of trap states, and (iv) improved carrier transport and collection efficiency due to core−shell structure and nanoscale morphology control. It is expected that the reported SiNWs/N-GQDs core−shell heterostructure device might be useful for high-performance optoelectronic applications in the near future.

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Section: Methodsmentioning

confidence: 99%

“…Au NPs were dissolved in the solution. For reducing the areal density of the SiNW array, etched SiNW templates were placed in 10 wt % aqueous KOH solution . In our case as grown SiNW templates were dipped into KOH solution for 1, 2, and 5 min, respectively.…”

Section: Methodsmentioning

confidence: 99%

Silicon Nanowire Arrays with Nitrogen-Doped Graphene Quantum Dots for Photodetectors

Mondal

Dey

Basori

2021

ACS Appl. Nano Mater.

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“…The RF and bias powers were 100 and 25 W, respectively. And the typical base pressure was approximately 2.3 × 10 −3 Pa. [29][30] The wet-etching process of the back-side silicon substrate is a key process to form a free-standing Si 3 N 4 membrane. Compared to the dry etching, it is easy to construct a wetetching system, as it has a high etching rate and a large number of wafers can be processed simultaneously.…”

Section: Ddr Process For the Patterning Of Socmentioning

confidence: 99%

Fabrication of high-aspect-ratio transmission grating using DDR process for 10 nm EUV resist evaluation by EUV interference lithography

Yoshifuji

Niihara

Harada

et al. 2019

Jpn. J. Appl. Phys.

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We have developed an EUV interference lithographic exposure tool to evaluate a resist. The target patterning size of this system is 10 nm and below in half pitch. Transmission grating fabrication is a key technology in EUV interference lithography. To replicate a 10-nm-line-and-space (L/S) resist pattern on a wafer, a 20-nm-L/S pattern is required for the transmission grating. The pitch size of the interference fringes is half the size of the absorber pattern of the transmission grating. For the chemically amplified positive tone resist process, instead of alkali development, organic development can be adopted to convert to a negative-tone chemical amplification resist process, and pattern collapse can be suppressed. In addition to this process, a dry development rinse (DDR) process is used. The DDR process with dry development successfully prevents pattern collapse at a high aspect pattern because there is no surface tension in the dry development of the DDR process. The EUV diffraction efficiencies of the fabricated gratings were measured to be 14%, 11% and 4% for 40, 30 and 20-nm-L/S pattern grating, respectively. Using these gratings, 20, 15 and 10 nm resist pattern might be replicated on a resist. And the diffraction efficiency was sufficient for interferometric exposure using synchrotron radiation.

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“…Material can be removed along desired directions and depths by exposing specific regions of the silicon substrate to etchants through the use of wet or dry etching processes. Wet etching 9 and dry etching 10 are the two main kinds of etching procedures. In dry etching, including reactive ion etching (RIE) and deep reactive ion etching (DRIE) 11 , gaseous substances diffuse into the substrate and the byproducts are evacuated using a vacuum system.…”

Section: Introductionmentioning

confidence: 99%

Multistage anisotropic wet etching by KOH for MEMS/NEMS structures

Rahman,

Bergren,

Burley

et al. 2024

Novel Patterning Technologies 2024

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Adaptive Optics (AO) systems add value in applications that involve light collection through turbulent media. Examples include Earth-based telescopes, microscopy, optical communication, and high-energy lasers, where solutions for addressing distorted images are needed. A key challenge in building AO systems involves achieving sufficient correction of distorted images through optical elements that can change shape with enough vertical displacement, spatial resolution, and frequency to adequately correct images. One such AO element is a deformable mirror that is bonded to an array of MEMs-based actuators that is made to operate using the Lorentz force. These elements can operate with very low power and are known as Low-Voltage Deformable Mirrors (LVDM). This study delves into a multi-step Potassium Hydroxide (KOH) etching process, encompassing surface preparation, mask deposition, lithography, and etching. KOH bulk micromachining proves critical in precision crafting of detailed 3D microstructures through anisotropic wet etching, offering unparalleled control over structural depth and morphology. LVDM Lorentz actuators are systematically arrayed in 20 × 20 geometries, interconnected with a flexible, reflective membrane mirror.Fabrication of the actuator arrays using Silicon on Insulator (SOI) wafers utilizes a multi-step KOH bulk process, with a design that integrates a crossbar, pillar, and springs, with a need for a crucial depth of up to 35 μm. This study provides a detailed account of the two-step KOH etching process, emphasizing critical parameters for successful Lorentz actuator fabrication on SOI wafers. Exploration of process variables like temperature, etchant concentration, and etching time is undertaken, considering their impact on etch rate and selectivity. Understanding these variables proves vital for achieving high-quality and reproducible MEMS structures in micro-/nanofabrication. The study also tackles challenges associated with multistage anisotropic wet etching, including etch pit formation, crystallographic defects, and surface roughness. Strategies to mitigate these challenges, such as surfactant use, additives, and post-etch treatments, are discussed, emphasizing their effectiveness in improving final device performance and reliability.

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Comparison of KOH and TMAH Etching on Sinw Arrays Fabricated via AFM Lithography

Cited by 8 publications

References 7 publications

Silicon Nanowire Arrays with Nitrogen-Doped Graphene Quantum Dots for Photodetectors

Silicon Nanowire Arrays with Nitrogen-Doped Graphene Quantum Dots for Photodetectors

Fabrication of high-aspect-ratio transmission grating using DDR process for 10 nm EUV resist evaluation by EUV interference lithography

Multistage anisotropic wet etching by KOH for MEMS/NEMS structures

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