EPR Spectroscopy of Diazoquinone–Novolac Resist Films Implanted with P+ and B+ Ions

• Published in: High energy chemistry Vol. 54; no. 2; pp. 115 - 122
• Main Authors: Brinkevich, D. I., Brinkevich, S. D., Oleshkevich, A. N., Prosolovich, V. S., Odzhaev, V. B.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-03-2020; Springer Nature B.V
• Subjects: Boron; Chemistry; Chemistry and Materials Science; Fluence; Free electrons; Ion implantation; Phosphorus; Photoresists; Physical Chemistry; Radiation Chemistry; Radicals; Silicon wafers; Single crystals; semiquinonoid radical anions; implantation; photoresist; boron; EPR; phosphorus
• ISSN: 0018-1439; 1608-3148
• DOI: 10.1134/S0018143920020046

The nature of stable radicals in FP9120 positive photoresist films implanted with boron and phosphorus ions and deposited on the surface of single-crystal silicon wafers has been determined using the EPR technique. At an implantation fluence of 6 × 10
15
cm
−2
, a narrow singlet isotropic line with a
g
-factor of 2.0064 is observed in the EPR spectrum. As the fluence increased to 1.2 × 10
16
cm
−2
, the
g
-factor decreased to values close to the
g
-factor of the free electron. The concentration of paramagnetic centers was higher during implantation of phosphorus ions than in the samples implanted with boron ions. This difference is due to a smaller contribution of nuclear stopping during B
+
implantation, which does not exceed 10–15% of electronic stopping. The formation of long-lived paramagnetic centers recorded by EPR a week after implantation of positive phenol–formaldehyde photoresist is due to the presence of a powerful system of conjugated >C=O and –C=C– multiple bonds in the structure of the radicals.