Towards Ge-based electronic devices: Increased longevity of alkanethiol-passivated Ge(100) in low humidity environments

Germanium is a critically important material for future complementary metal-oxide-semiconductor devices, however, to maximise its potential it is necessary to develop a robust passivation process that prevents Ge re-oxidation for a queue time of 24 h. Self-assembled monolayers (SAMs) of alkanethiols on Ge have previously been shown to inhibit oxidation; however, re-oxidation eventually occurs when exposed to ambient conditions. Herein, it is shown that humidity plays a key role in the degradation of the SAM, ultimately resulting in re-oxidation. To demonstrate this, thiol-passivated Ge(100) surfaces are exposed to controlled humidity environments with different levels of relative humidity (RH). The rate of re-oxidation of the Ge surfaces are tracked using X-ray photoelectron spectroscopy and water contact angle analysis to discern what role RH plays in the re-oxidation of the Ge and the degradation of the SAM passivation. Atomic force microscopy data is presented to show that humidity-mediated re-oxidation of the Ge has little or no impact on the route mean square roughness of those surfaces. Finally, atomistic modelling of thiol-SAM passivated Ge in the presence of water molecules has been studied using first principles density functional theory in order to simulate experimental conditions and to understand the atomic level processes that determine stability in hydrophilic and hydrophobic configurations

Pattern Transfer of Sub-10 nm Features via Tin-Containing Block Copolymers

Tin-containing block copolymers were investigated as materials for nanolithographic applications. Poly(4-trimethylstannylstyrene-block-styrene) (PSnS-PS) and poly(4-trimethylstannylstyrene-block-4-methoxystyrene) (PSnS-PMOST) synthesized by reversible addition–fragmentation chain transfer polymerization form lamellar domains with periodicities ranging from 18 to 34 nm. Thin film orientation control was achieved by thermal annealing between a neutral surface treatment and a top coat. Incorporation of tin into one block facilitates pattern transfer into SiO_2 via a two-step etch process utilizing oxidative and fluorine-based etch chemistries

Method and Apparatus for Adaptive Process Control of Critical Dimensions During Spin Coating Process

A spin coating process for controlling the mean thickness of photoresist on the surface of a semiconductor wafer. The wafer surface has a central axis normal to the surface. The process comprises the steps of applying the solution to the wafer surface and spinning the wafer about the central axis at a spindle speed until the solution has dried. The spindle speed is a function of the desired mean thickness of the photoresist, the barometric pressure and the relative humidity. The spindle speed is determined from a statistical model described by the equation: MT=A+BxRH+CxBP+D/SS1/2 wherein: MT is mean thickness in Å; RH is relative humidity in percent; BP is barometric pressure in mm of Hg; SS is spindle speed in rpm; and A, B, C and D are constant coefficients

Plasma Deposition of Spin Chucks to Reduce Contamination of Silicon Wafers

An apparatus for delivering a fluidic media to a wafer includes a housing defining a process chamber. A fluidic media delivery member is coupled to the process chamber. A rotatable chuck is positioned in the process chamber. The rotatable chuck has a wafer support surface coated with a coating material. A vacuum supply line is coupled to the rotatable chuck

Photoresist Coating Process Control With Solvent Vapor Sensor

An apparatus for spin coating surfaces with liquid polymer comprises a spin coating chamber having a rotatable chuck for supporting an object to be coated. A distributor introduces gases into the chamber. A solvent vapor and carrier gas supply provides a carrier gas having a controlled level of solvent vapor therein within the range of from 0 to saturation concentrations of solvent vapor. A solvent vapor sensor is positioned with respect to the coating chamber to produce signals which correspond to the concentration of solvent vapor in the coating chamber. A control means is connected to the solvent vapor concentration sensor and to the solvent vapor and carrier gas supply means for controlling the level of solvent concentration in the carrier gas supplied by the solvent vapor and carrier gas supply means. The solvent vapor level can be obtained by controlled mixing of solvent-bearing and solvent-free gas streams, or by injection of solvent into a gas stream by means of an atomizer, for example. The solvent vapor concentration sensor includes a component positioned for exposure to solvent vapor and which has a property which changes as a function of the solvent vapor concentration to which it is exposed. A preferred sensor can include a membrane, the vibrational frequency of which changes as a function of the solvent vapor concentration to which it is exposed; a surface, an electrical property of which changes as a function of the solvent vapor concentration to which it is exposed; a sensor which detects an acoustical property which changes as a function of the solvent vapor concentration to which it is exposed; or an optical detector which detects an optical property which changes as a function of the solvent vapor concentration to which it is exposed

Plasma Deposition of Spin Chucks to Reduce Contamination of Silicon Wafers

An apparatus for delivering a fluidic media to a wafer includes a housing defining a process chamber. A fluidic media delivery member is coupled to the process chamber. A rotatable chuck is positioned in the process chamber. The rotatable chuck has a wafer support surface coated with a coating material. A vacuum supply line is coupled to the rotatable chuck

Common surgical procedures in pilonidal sinus disease: A meta-analysis, merged data analysis, and comprehensive study on recurrence

Abstract We systematically searched available databases. We reviewed 6,143 studies published from 1833 to 2017. Reports in English, French, German, Italian, and Spanish were considered, as were publications in other languages if definitive treatment and recurrence at specific follow-up times were described in an English abstract. We assessed data in the manner of a meta-analysis of RCTs; further we assessed non-RCTs in the manner of a merged data analysis. In the RCT analysis including 11,730 patients, Limberg & Dufourmentel operations were associated with low recurrence of 0.6% (95%CI 0.3–0.9%) 12 months and 1.8% (95%CI 1.1–2.4%) respectively 24 months postoperatively. Analysing 89,583 patients from RCTs and non-RCTs, the Karydakis & Bascom approaches were associated with recurrence of only 0.2% (95%CI 0.1–0.3%) 12 months and 0.6% (95%CI 0.5–0.8%) 24 months postoperatively. Primary midline closure exhibited long-term recurrence up to 67.9% (95%CI 53.3–82.4%) 240 months post-surgery. For most procedures, only a few RCTs without long term follow up data exist, but substitute data from numerous non-RCTs are available. Recurrence in PSD is highly dependent on surgical procedure and by follow-up time; both must be considered when drawing conclusions regarding the efficacy of a procedure