TRANSETCH - N
TRANSETCH-N is a purified reagent, derived from ortho-phoshoric acid, which selectively etches silicon nitride or aluminum oxide in the presence of silicon dioxide or silicon. When used as directed, it produces openings in these films with a degree of resolution comparable to the best obtainable with SiO2 in conventional planar technology, but with essentially no effect on exposed silicon or silicon dioxide surfaces.
The photoresist materials, processes and equipment used in conventional etching operations are retained and the additional equipment required is minimal and inexpensive.
TRANSETCH-N contains no fluorides. Unlike etchants based on fluoride chemistry, TRANSETCH-N produces no undercutting and therefore provides a wide margin of safety in the selection of etching times. TRANSETCH-N is stable and logn-lived. The only attention which it may require in use is the addition of small amounts of wafer to replace that lost through evaporation.
UNIQUE ADVANTAGES :
• Convenient, ready to use.
• Selective, etches silicon nitride, gallium nitride or aluminum oxide films.
• Re-usable, does not weaken with use.
• Produces no noxious fumes, requires no hoods or venting.
• Virtually eliminates over-etching and under-cutting.
• Ensures successful planar passivation of silicon semiconductor devices.
PROPERTIES :
| TRANSETCH-N
| |
Appearance | Liquid Colorless, odorless |
Specific Gravity @ 20¡É | 1.757 |
Boiling Temp. (with evolution H2O) | 180¡É |
Resist Compatibility | Nega & Posi |
Tank | Glass or polypropylene |
Etch Rate @ 180¡É Aluminum oxide | 120 ¡Ê/min |
Silicon nitride | 125 ¡Ê/min |
Gallium nitride | 80 ¡Ê/min |
Silicon dioxide | 1 ¡Ê/min |
Silicon | 1 ¡Ê/min |
APPLICATION :
• TRANSETCH-N is employed in the new technology for surface passivation of semiconductor devices, based upon the use of deposited Si3N4 and Al2O3 films.
• This technology leads to the high quality and reliability of semiconductor products and is particularly helpful in stabilizing MOS and MIS devices. Inversion layers and ion migration are virtually eliminated : leakage currents approach theory; and surface states are notably controlled.