Apr 20, 2020

buffered oxide etch, or BOE). "5:l" refers to five parts by weight of 40-weight-percent ammonium fluoride (the buffer) to one part by weight 49-weight-percent hydrofluoric acid, which results in a total of about 33% NH4F and 8.3% HF by weight [22]. Produced commercially, the pH is about 3. Notes: This etchant can be masked with photoresist (the TECHNICAL PRODUCT INFORMATION - Fujifilm Buffered Oxide Etchant • FUJIFILM Buffered Oxide Etchantsare silicon oxide etchants formulated from high purity 49% Hydrofluoric Acid and high purity 40% Ammonium Fluoride. •Formulations are available in standard NH4F:HF ratios or made to customer specification. •Stringent control of both hydrofluoric acid and ammonium fluoride MAteriAl CoMPAtibility Buffered Oxide Etch 5:1 (40% NH4F + 49% HF) Silicon Dioxide PFA Tank with heat exchange coils Quickdump Rinse H2O Chemical removal PVDF Quickdump Post Hot Phos Rinse H2O Acid Rinse PVDF Quickdump Megasonic Post Piranha Rinse H2O Acid rinse, Sulfate removal PVDF Quickdump Megasonic

Buffered Oxide Etch INRF Application note Process name: BOE . Overview . Buffered oxide etch is used to etch thin films of oxide or polysilicate glass (some have used it to etch cavities in glass). It is a buffered HF mixture that slows down and controls the attack rate of HF on oxide. This is a level-1 process and requires basic INRF safety

concentrations (e.g., in 49% HF) and attack oxide even faster than HF, [ 171. Thus, the etch rate increases faster than linearly with HF concentration. In buffered 15 M HF solutions, for pH values above about 1, the concentration of HF, is greater than that of HF [ 171. For more acidic solutions, there is sufficient hydrogen to combine

Silicon Dioxide Etch using Buffered Hydrofluoric Acid

Buffered Oxide Etch (BOE) is a mixture of HF and NH4F in different proportions. 6:1 BOE etching means that 40% NH4F: 49% HF = 6:1 (volume ratio) is mixed. HF is the main etchant and NH4F is used as a buffer. The concentration of [H+] was fixed by NH4F to maintain a certain etching rate. SDS SAFETY DATA SHEET - Home | Bionium