湿法清洗和蚀刻化学品简单资料

1、WET ETCH &CLEAN ChemicalPage 1Page 2Differences between The Etch rate: 49%HF HF(50:1)DHF(100:1) on the same condition to the same material .In Backside etch , 49%HF is used to etch the nitride on the back side deposited at Diffusion ,which is much thick ,about 1600A. DHF (100:1) Etch rate is the low

2、est among the three chemicals,so it is used to preclean ,that is to etch a very thin oxide layer.As to oxide etch , HF(50:1) etch rate is in a reasonable range ,so it is suitable to etch oxide layer completely and safely.Page 3BOE (Buffered Oxide Etch)NH4F used as buffer agent , F - ion supplier,so

3、the F- concentration keeps stable ,that means the Etch rate keeps stable.Surfactants are often added to improve wetting, based on the capillary mechanism.Benefit compared to DHF: 1) Low selectivity oxide etch for DRAM contact pre-clean 2) Prevent photo resist liftoff for KV, Dual gate processPage 4m

4、etalmetaldielectric .Page 5SC1Components: NH4OH:H2O2:H2O=1:2:$Temperature: 30CNH4OH:H2O2:H2O=1:2:50Function: Particle removal NH4OH:H2O2:H2O=1:2:30Function: PR removal Page 6SC1 to remove Particle OxidationDissolutionOxidation mechanismSurface etchingElectrical repulsionElectrical repulsion mechanis

5、mMechanism: oxidation and electrical repulsion Page 7SC2Components: HCl:H2O2:H2O=1:1:50Temperature: 30CFunction: metal contamination removalMechanism : SC2 provides a low pH environment. Alkaline ions (Na, K, Li metals), hydroxide of Al, Mg, Fe, Zn (insoluble in NH4OH SC1), and residual trace metal (Au/Cu not completely desorbed by SC1) will be dissolved in SC2.Page 8H3PO4 (Phosphoric Acid)Components: H3PO4Temperature: 160CFunction: Nitride strip, ER = 50 A/minMechanism:Si3N4 + 6H2O - 3SiO2 + 4NH3 (H3PO4 as catalyst)There is a thin Oxi