Diazonaphthoquinone

Diazonaphthoquinone
IUPAC name 2-Diazo-2H-naphthalen-1-one
Other names 1,2-Naphthoquinone diazide
Identifiers
CAS number	879-15-2
Jmol-3D images	Image 1
SMILES O=C(C(C=C2)=[N]=[N])C1=C2C=CC=C1
Properties
Molecular formula	C10H6N2O
Molar mass	170.17 g mol−1
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Diazonaphthoquinone (DNQ) is a diazo derivative of naphthoquinone. Upon exposure to light, it undergoes a Wolff rearrangement to form a ketene.^[1] This chemical reaction is exploited with a variety of diazonaphthoquinone derivatives in the semiconductor industry.

Diazonaphthoquinone sulfonic acid esters are commonly used as components of photoresist materials for semiconductor manufacturing.^[2][3] In this application DNQs are mixed with Novolac resin, a type of phenolic polymer. The DNQ functions as a dissolution inhibitor. During the masking/patterning process, portions of the photoresist film are exposed to light while others remain unexposed. In the unexposed regions of the resist film, the DNQ acts as a dissolution inhibitor and the resist remains insoluble in the aqueous base developer. In the exposed regions, the DNQ forms a ketene, which, in turn, reacts with ambient water to form a base soluble indene carboxylic acid. The exposed regions of the photoresist film become soluble in aqueous base; thus allowing the formation of a relief image during development.

References

1. ^ N. C. de Lucas, J. C. Netto-Ferreira, J. Andraos, and J. C. Scaiano (2001). "Nucleophilicity toward Ketenes: Rate Constants for Addition of Amines to Aryl Ketenes in Acetonitrile Solution". J. Org. Chem. 66 (5): 5016–5021. doi:10.1021/jo005752q. PMID 11463250. 
2. ^ Chemical Information Review Document for Diazonaphthoquinone Derivatives Used in Photoresists, National Toxicology Program, January 2006
3. ^ Integrated Circuits: A Brief History