The influence of pH and H2O2 on surface quality and material removal rate during W-CMP

With the evolution of integrated circuits, the transition from polycrystalline silicon to aluminum as the gate electrode has become prevalent due to its inherent advantages. This study considers the impacts of pH, H2O2 and alanine on the aluminum removal rate and surface roughness during chemical mechanical polishing (CMP) with abrasive colloidal silica. Alanine was incorporated as a complexing agent in the polishing slurry in an acidic environment. The mechanistic role of alanine in the aluminum CMP process was investigated with various techniques, including electrochemical tests, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV–visible spectroscopy (UV–vis). Additionally, density functional theory (DFT) calculations were used to examine the quantum chemical parameters of alanine and elucidate the complexation mechanism. The experimental results indicated that at an alanine concentration of 1.5 wt%, the Al removal rate was 2124.07 Å min−1 with a surface roughness of 1.33 nm. The interactions between alanine and the aluminum ions (Al3+) yielded soluble Al-alanine complexes, which facilitated corrosion on the Al and enhanced the removal rate.

Section: Resultsmentioning

confidence: 99%

The Role of Alanine in the Chemical Mechanical Polishing of Aluminum

Cao,

Wang,

Luo

et al. 2023

“…The preparation of polishing solution is an important part of CMP, which is related to the surface quality and material removal rate of the sample. 16 In the past, the oxidant of the polishing solution was selected generally with high corrosive chemical reagents, such as nitric acid and hydrofluoric acid. 18 In the traditional polishing experiment, porous polyurethane pads were used for polishing pads, W3.5 white corundum was used for abrasives, glycerol concentration was 3%, polyvinyl nonylphenol ether 0.3% was used as the other polishing solution components, oxalic acid and ethylenediamine were used to adjust the pH.…”

Section: Methodsmentioning

confidence: 99%

Preparation and Performance Testing of Green Non-toxic Polishing Solution for Medical Titanium Alloy

Zhang,

Zou,

Pang

et al. 2024

To obtain a lower toxic residue on medical titanium alloy surfaces in a chemical mechanical polishing (CMP) process, a new green polishing solution is proposed. The humoral fluid was selected as the basic solution in which the silica abrasive particles were used as the grinding particles, and H2O2 was added as the oxidant. A CMP test was carried out for its performance investigation with titanium alloy material. Then the surface roughness and material removal ratio were analyzed and compared with that of an existing polishing solution condition. Finally, the toxic residue of the titanium alloy samples was obtained by scanning electron microscopy. The experimental results indicate that a better material removal rate and surface roughness of titanium alloy with humoral polishing solution were obtained compared to existed polishing solution conditions. More importantly, the content of toxic elements on the sample surface was significantly reduced due to the greater amount of aluminum and vanadium ions dissolved in the polishing solution, which is more beneficial for its application in the medical prosthetics field. This study provides a new reference for the toxic residue reduction on the material surface of medical titanium alloy in CMP process.

“…Consequently, this study necessitates the usage of a pulse laser for precise machining purposes. [30][31][32] The experimental machining system consists of an all-solid-state UV nanosecond laser (parameters are shown in Table II), a beam expander, a mirror, a scanning galvanometer, Ftheta lens, a computer, and a water-cooling device, as shown in Fig. 2.…”

Section: Experimental Designmentioning

confidence: 99%

Experimental Study on the Influence of Ultraviolet Laser Parameters on the Micro Machining Quality of Silicon Carbide Ceramic

Zhao,

Ruan,

Chen

et al. 2023

Self Cite

Silicon carbide(SiC) ceramics have great application value in microelectronics and semiconductors due to their small dielectric constant, high thermal conductivity, and small thermal expansion coefficient. However, due to its high hardness and brittleness, defects such as stress concentration, microcracks, and an excessively large heat-affected zone are prone to occur in traditional machining methods. In this paper, the ultra-thin SiC surface was micro-grooved by ultraviolet(UV) laser. The effects and rules of various machining parameters (scanning speed, repetition frequency, pulse width, defocus amount) in UV laser micro-grooves machining on the surface quality, machining depth, and cross-sectional morphology of SiC were studied. The experimental results showed that the surface roughness of SiC micro-grooves decrease with the increase of scanning speed; The relatively small surface roughness (R a 0.72 μm) could be obtained at a scanning speed of 500 mm s−1 and a repetition frequency of 40 kHz; Under low pulse width of 5 ns, high repetition frequency of 50 kHz, and high scanning speed of 500 mm s−1, micro-grooves with a relative error of 2.3% in removal depth could be obtained; The taper of the micro-groove section first decreases and then increases with the defocus from negative to positive, and reached the minimum value of 5° when the defocus positive 0.6 mm.