901482

Hexamethyldisilazane

20% solution in xylene

• Synonym(s): HMDS
• Linear Formula: C₆H₁₉NSi₂
• CAS Number: 999-97-3
• UNSPSC Code: 12352103
• NACRES: NA.23

Properties

• form: liquid
• InChI: 1S/C6H19NSi2/c1-8(2,3)7-9(4,5)6/h7H,1-6H3
• InChI key: FFUAGWLWBBFQJT-UHFFFAOYSA-N

Description

General description

The product is used to augment the adhesion of photoresist on silicon and SiO₂ surfaces.
The effectiveness of HMDS on adhesion is correlated with the reactivity of this compound with surface hydroxyl groups to form a new siloxane end product, i.e. Si-O-Si(CH₃)₃. This newly formed termination on the substrate renders the surface more hydrophobic in character and leads to greater wettability by photoresist. The latter condition is a crucial factor in good bonding. As a result of these altered characteristics due to the surface chemistry, the treated silicon surfaces become highly compatible with both negative and positive photoresists.

Application

HMDS preparations are generally applied to the silicon wafer while spinning, prior to the application of photoresist. As an alternative procedure, the wafers may be immersed in HMDS preparations and allowed to dry after removal.

Features and Benefits

• Ready-to-use preparations for surface treatment of silicon.
• Promotes photoresist adhesion on silicon and SiO₂ films.
• Prevents lift-off at edges of photoresist and reduces undercutting.
• Ensures full-line resolution.
• Improves yields of MOS and integrated silicon devices.

Safety Information

• pictograms: GHS02,GHS06,GHS08
• signalword: Danger
• hcodes: H226,H304,H311,H315,H319,H332,H335,H373,H412
• pcodes: P210 - P273 - P280 - P301 + P310 - P303 + P361 + P353 - P331
• Hazard Classifications: Acute Tox. 3 Dermal - Acute Tox. 4 Inhalation - Aquatic Chronic 3 - Asp. Tox. 1 - Eye Irrit. 2 - Flam. Liq. 3 - Skin Irrit. 2 - STOT RE 2 - STOT SE 3
• target_organs: hearing organs, Respiratory system
• Storage Class: 3 - Flammable liquids
• wgk_germany: WGK 2
• flash_point_f: 76.1 °F
• flash_point_c: 24.5 °C