H 1345 (OTTO) Hexamethyldisilazane, 98% Cas 999-97-3 - used as an adhesion promoter for photoresist. Best results are obtained by applying HMDS from the gas phase on heated substrates. H 1345 (OTTO) Hexamethyldisilazane, 98% Cas 999-97-3 - used as a solvent in organic synthesis and organometallic chemistry. It is often used as an adhesion promoter for photoresist in photolithography. Further, it is used for the preparation of trimethylsilyl ethers from hydroxy compounds. It is used as an alternative to critical point drying during sample preparation in electron microscopy. It is added to analyte to get silylated diagnostic products during pyrolysis in gas chromatography- mass spectrometry.