The black silicon method: a universal method for determining the parameter setting of a fluorine-based reactive ion etcher in deep silicon trench etching with profile control

Abstract

Very deep trenches (up to 200 pm) with high aspect ratios (up to 10) in silicon and polymers are etched using a fluorine-based plasma (SFd02/CHF3). Isotropic, positively and negatively (i.e. reverse) tapered as well as.fully vertical walls with smooth suriaces are achieved by controlling the plasma chemistry. A convenient way to find the processing conditions needed for a vertical wall is described the black silicon method. This new procedure is checked for three different reactive ion etchers (RIE), two parallel-plate reactors and a hexode. The influence of the RF power, pressure and gas mixture on the profile will be shown. Scanning electron microscope (SEM) photos are included to demonstrate the black silicon method, the influence of the gases on the profile, and the use of this method in fabricating microelectromechanical systems (MEMS).

Ultrasonic Transducers

“…To fulfill these requirements, DRIE process is developed. By exploiting the new opportunities provided by this powerful tool, many attractive MEMS devices have been fabricated [62][63][64][65][66][67][68][69][70].…”

“…Depending on demands, the vertical dimension can vary from several microns to several hundreds of microns. What is more, by adjusting reaction parameters such as chamber pressure, gas concentrations, or RF power, it is possible to realize diversely taped profiles, especially those with vertical sidewalls [63]. In last section, several microstructures fabricated by DRIE process have been demonstrated (See Fig.…”

Fabrication of Nanopillar Micropatterns by Hybrid Mask Lithography for Surface-Directed Liquid Flow

“…Plasma etching and photolithography are generally used to fabricate nanopatterned surfaces containing nanopillar arrays. Reactive ion etching (also known as plasma etching) can be used to fabricate black silicon, which is a needle-like structure produced by using non-optimal etching conditions [20,21]. Its sharp structure produces a hydrophobic surface on a wafer.…”

Fabrication and doping of silicon micropillar arrays for solar light harvesting

“…[35] Another method to create large areas of silicon pillars is maskless etching, which uses a technique called black silicon etching. [37,38] By tuning the settings of the etch process, small contaminations on the wafer, i.e. deliberately created by-products or reaction intermediates from the etch process, can act as nanomasks on the silicon surface, resulting in the formation of spikes.…”

“…deliberately created by-products or reaction intermediates from the etch process, can act as nanomasks on the silicon surface, resulting in the formation of spikes. [38] As the technique does not require a mask, wafer scale etching is easily achieved, and the fabrication of silicon pillars with diameters between 50-80 nm, with heights up to 1600 nm, has been shown. [37] Note that these structures are randomly positioned, and pillar diameter and pitch cannot be defined by design.…”