Process Technology - Cleaning processes from

Wafer Cleaning Solutions

Wafer Cleaning Solutions for Critical Wet Processing Applications for Semiconductor, MEMs, LED, and III-V Compound

RENA’s goal is to partner with its customers in creating and developing wet processing solutions that effectively serve their customer’s needs.

Through our innovative patented technologies and field-proven processing solutions, RENA offers reliable, consistent results for many of the difficult and critical wet processing applications. To complement RENA’s advanced Wet Processing Solutions and advanced Wet Bench platforms, RENA brings a philosophy that is founded on customer commitment. Each and every product we offer is built on Commitment.

Contact us for a consultation to help with your critical Wet Processing Challenges.

Features and Benefits:

Field-Proven Solutions for:
SC1
SC2
RCA Clean
Surface Pre-clean
Piranha Etch-Clean
FOEL Clean
BOEL Clean

SC1 (RCA Organic/Particle Clean)

SC1 Standard Clean 1 as a final polishing clean to remove the last residues or to clean new wafers before processing. The SC-1 solution was designed to remove from Si, oxide, and quartz surfaces organic contaminants that are attached by both the solvating action of the NH4OH and the powerful oxidizing action of the alkaline H2O2. SC-1 dissolves the think native oxide layer on Si at a very low rate and forms a new oxide on the Si surface by oxidation at approximately the same rate. This oxide regeneration is now believed to be an important factor in the removal of particles and chemical impurities.

Standard Clean 1 Solution includes:

Quartz Construction Megasonic
22-75o C Temp control w/inline heater
Filter recirculation
Chemical bulk fill w/ Spiking capability
Auto Lid
Cooldown reservoir w/level and Temp monitor

SC2 (RCA Organic/Particle Clean)

Standard Clean 2 is a procedure for removing metal ions from silicon wafers. The decontamination works based on sequential oxidative desorption and complexing with H2O2-NCl-H2O (RCA-2). Typically this is preceded by an RCA-1 clean (SC-1, H2O2-NH4OH-H2O) to remove organic residues. In the process, it oxidizes the silicon and leaves a thin oxide layer on the surface of the wafer. The SC2 solution was designed to dissolve and remove from the Si surface alkali residue and any residual trace metal as well as metal hydroxides. SC-2 does not etch Si or SiO2.

RCA (Clean – Si Wafer clean)

RCA clean is used to remove organic residues from silicon wafers. In the process, it oxidizes the silicon and leaves a thin oxide layer on the surface of the wafer. The general recipe for RCA-1 is: 5 parts water (H2O), 1 part 27% ammonium hydroxide (NH4OH), and 1 part 30% hydrogen peroxide (H2O2). The process consists of two consecutively applied hot solutions known as RCA Standard Clean, SC-1 and SC-2, featuring pure and volatile reagents. These solutions have been widely used in their original or modified form for over 40 years in the fabrication of Si semiconductor devices. The SC-1 solution for the first processing step consists of a mixture of NH4OH, H2O2, and H2O; also known as APM for ammonia/peroxide mixture. The SC-2 solution for the second processing step consists of a mixture of, HCl, H2O2, and H2O; also known as HPM for hydrochloric/peroxide mixture. With RENA you get a hi-throughput RCA Clean Solution.

RCA Solution features:

Low operating costs due to lower DI water usage and efficient chemical consumption
Tight process controls driven by RENA IDX Automation Software.
Marangoni Drying or Vapor Drying

BEoL Clean (Back End of Line Clean)

Plasma-stripping photoresist mask and impurities after pattern etching

Post-stripping first cleaning step using an organic solvent or aqueous/organic solvent mixtures (semi-aqueous solvent)
Predeposition cleaning with brush scrubber, megasonic treatment in DI H2O, application of cryogenic aerosols, or use of supercritical CO2

Resist strip applications using an advanced immersion wet bench have been in use for years, in particular for BEOL applications. Due to the configurability and advanced features found in RENA platforms, solvent benches can be used for polymer removal, both in the FEoL and after metallization.

RENA optimizes process time, and chemical usage through the use of the medium with partial replenishment. Defect rates are kept low due to the advanced process monitoring and filtering systems. Intermediate rinses can be implemented without loss in productivity. RENA enhances the performance of the strip or clean by megasonic, ultrasonic, and/ or physical agitation.

FEoL Clean (Front End of Line Clean)

FEOL involves Plasma-stripping photolithographic mask and impurities after ion implantation or etching.

FEoL Clean features:

Aqueous-based residue removal and cleaning using SPM (sulfuric acid and hydrogen peroxide mixture) or O3(ozonated) DI H2O (deionized H2O)
Critical surface cleaning and surface conditioning prior to gate oxide deposition usingSC-1/SC-2 (RCA Standard Clean 1 and 2), HF or dilute ozonated SC-1, dilute SC-2 and dilute HF (dHF) solutionRinsing with DI H2O
Wafer drying using IPA (isopropyl alcohol) in preparation for high-temperature oxide growth or polysilicon deposition or metal sputtering

Prediffusion Cleaning

Native oxide film elimination for the oxide film deposition. Particle removal must be complete and etch rates must be tightly controlled. Resulting in a surface that must be free from particulates, metallics, and organic contamination. In some cases, such as the deposition of epitaxial Si, it needs to have aH-terminated Si surface that is free from any native or chemical oxide.