Dataset Information

The Effect of Doping on the Digital Etching of Silicon-Selective Silicon-Germanium Using Nitric Acids.

ABSTRACT: Gate-all-around (GAA) field-effect transistors have been proposed as one of the most important developments for CMOS logic devices at the 3 nm technology node and beyond. Isotropic etching of silicon-germanium (SiGe) for the definition of nano-scale channels in vertical GAA CMOS and tunneling FETs has attracted more and more attention. In this work, the effect of doping on the digital etching of Si-selective SiGe with alternative nitric acids (HNO3) and buffered oxide etching (BOE) was investigated in detail. It was found that the HNO3 digital etching of SiGe was selective to n+-Si, p+-Si, and intrinsic Si. Extensive studies were performed. It turned out that the selectivity of SiGe/Si was dependent on the doped types of silicon and the HNO3 concentration. As a result, at 31.5% HNO3 concentration, the relative etched amount per cycle (REPC) and the etching selectivity of Si0.72Ge0.28 for n+-Si was identical to that for p+-Si. This is particularly important for applications of vertical GAA CMOS and tunneling FETs, which have to expose both the n+ and p+ sources/drains at the same time. In addition, the values of the REPC and selectivity were obtained. A controllable etching rate and atomically smooth surface could be achieved, which enhanced carrier mobility.

SUBMITTER: Li Y

PROVIDER: S-EPMC8147633 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The Effect of Doping on the Digital Etching of Silicon-Selective Silicon-Germanium Using Nitric Acids.

Li Yangyang Y Zhu Huilong H Kong Zhenzhen Z Zhang Yongkui Y Ai Xuezheng X Wang Guilei G Wang Qi Q Liu Ziyi Z Lu Shunshun S Xie Lu L Huang Weixing W Liu Yongbo Y Li Chen C Li Junjie J Lin Hongxiao H Su Jiale J Zeng Chuanbin C Radamson Henry H HH

Nanomaterials (Basel, Switzerland) 20210503 5

Gate-all-around (GAA) field-effect transistors have been proposed as one of the most important developments for CMOS logic devices at the 3 nm technology node and beyond. Isotropic etching of silicon-germanium (SiGe) for the definition of nano-scale channels in vertical GAA CMOS and tunneling FETs has attracted more and more attention. In this work, the effect of doping on the digital etching of Si-selective SiGe with alternative nitric acids (HNO<sub>3</sub>) and buffered oxide etching (BOE) wa ...[more]

PMID: 34063569

Similar Datasets

Project description:The combination of metal-assisted chemical etching (MACE) with colloidal lithography has emerged as a simple and cost-effective approach to nanostructure silicon. It is especially efficient at synthesizing Si micro- and nanowire arrays using a catalytic metal mesh, which sinks into the silicon substrate during the etching process. The approach provides a precise control over the array geometry, without requiring expensive nanopatterning techniques. Although MACE is a high-throughput solution-based approach, achieving large-scale homogeneity can be challenging because of the instability of the metal catalyst when the experimental parameters are not set appropriately. Such instabilities can lead to metal film fracture, significantly damaging the substrate and thus compromising the nanowire array quality. Here, we report on the critical parameters that influence the stability of the metal catalyst layer for achieving large-scale homogeneous MACE: etchant composition, metal film thickness, adhesion layer thickness, nanowire diameter and pitch, metal film coverage, Si/Au/etchant interface length, and crystalline quality of the colloidal template (grain size and defects). Our results investigate the origin of the catalyst film fracture and reveal that MACE experiments should be optimized for each Si wire array geometry by keeping the etch rate below a certain threshold. We show that the Si/Au/etchant interface length also affects the etch rate and should thus be considered when optimizing the MACE experimental parameters. Finally, our results demonstrate that colloidal templates with small grain sizes (i.e., <100 μm2) can yield significant problems during the pattern transfer because of a high density of defects at the grain boundaries that negatively affects the metal film stability. As such, this work provides guidelines for the large-scale synthesis of Si micro- and nanowire arrays via MACE, relevant for both new and experienced researchers working with MACE.

Dataset Information

The Effect of Doping on the Digital Etching of Silicon-Selective Silicon-Germanium Using Nitric Acids.

Publications

The Effect of Doping on the Digital Etching of Silicon-Selective Silicon-Germanium Using Nitric Acids.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets