The Cleaning Effects of  HF  ‐  HNO 3 ‐  H 2 O 2 System

Abstract

We have studied the characteristics of the mixture of HNO3 , HF , and H2O2 chemicals called the controlled slight etch (CSE) solution as an effective wafer cleaning solution. The silicon etch rate in the CSE solution was not dependent on HF concentration of the solution, while that in a mixture of HNO3 and HF was linearly dependent on HF concentration. The CSE solution reduced the surface concentrations of Fe and Cu ions below a concentration of 1010 normalatom/cm2 on the intentionally contaminated wafers and suppressed average surface microroughness increase in comparison to slight etch (SE) solution. X‐ray photoelectron spectroscopy (XPS) showed that the CSE cleaning does not leave chemical oxide on the surface. The average breakdown field for the CSE‐cleaned sample was 11.5MV/normalcm . We explained the etching mechanism that the H2O2 species in the CSE solution slows down the rate of oxidation reaction of the silicon wafer by interrupting autocatalytic reaction of HNO3 .

Preparation and Characterization of Aligned Carbon Nanotube–Ruthenium Oxide Nanocomposites for Supercapacitors

“…To improve the capacitance values of carbon nanotubes, several methods have been proposed, including: a) Treatment with acids or bases for activating the CNTs and/or increasing the micropore volume of the CNTs,7 and b) modification of the CNTs with conducting polymers such as polypyrrole,8 or with transition‐metal oxides 9–11. Because of the degradation of polymers, the CNT/conducting polymer composites do not have a high cycle life (>100 000 cycles) 12.…”

“…The supercapacitive behavior of several transition‐metal oxides, such as RuO 2 ,1, 13 IrO 2 ,14 and NiO x ,15 have already been reported. In order to utilize both advantages of double‐layer capacitance and pseudo‐capacitance, metal oxide/carbon nanotube composite electrodes9–11 have been introduced recently. Transition‐metal oxides attached to CNTs are expected to be more useful due to their enhanced stability and high conductivity 9.…”

Effect of Surface Treatments on the Electrical Properties of Fluorinated Silicon Oxides

“…Interestingly, no GDT is seen in CN-5B, which is believed to be due to the growth of native oxide during the etching process by the oxidized reaction of HNO 3 and Si. 16 On the contrary, CN-6B used H 2 O 2 instead of H 2 O to suppress the autocatalytic reaction of HNO 3 with Si, hence little native oxide was obtained (GDT ϭ 5 min, not shown in this figure). Furthermore, chemical oxides formed by HNO 3 were etched off completely by HF because the rate-determining step was the oxidation of Si by HNO 3 .…”

“…The etching processes of CN-5B and CN-6B were of similar etching solutions, a HNO 3 /HF/H 2 O called slight etch (SE) solution and a HNO 3 /HF/H 2 O 2 called controlled slight etch (CSE) solution. 15,16 After finishing the last three etching processes, the substrates were immediately dried with nitrogen blown without a DI water rinse.…”

Fundamental Studies in Selective Wet Etching and Corrosion Processes for High-Performance Semiconductor Devices

“…Furthermore, we focus on the influence of hydrogen peroxide on copper corrosion from a mechanistic and kinetic stand point. Hydrogen peroxide is a common component in many cleaning formulations used for particle and residue 44 removal in the fabrication of IC devices 116,117,118,119,120,121,122 . The chapter begins with a brief overview of principles and basic concepts of corrosion, Cu in particular.…”