Formation of Ammonium Salts and Their Effects on Controlling Pattern Geometry in the Reactive Ion Etching Process for Fabricating Aluminum Wiring and Polysilicon Gate

Autor:	Junichi Tonotani, Kazuyuki Sugita, Shuichi Saito, Masashi Yamage
Rok vydání:	2002
Předmět:	Materials science Physics and Astronomy (miscellaneous) Passivation Hydrogen General Engineering Analytical chemistry General Physics and Astronomy chemistry.chemical_element Photoresist Nitrogen chemistry X-ray photoelectron spectroscopy Etching (microfabrication) Aluminium Reactive-ion etching
Zdroj:	Japanese Journal of Applied Physics. 41:2220-2224
ISSN:	1347-4065 0021-4922
DOI:	10.1143/jjap.41.2220
Popis:	The role of N2 gas addition in the reactive ion etching (RIE) processes for aluminum wiring and polysilicon gate fabrication was investigated. With an increase in the amount of N2 gas added to the etching gas, the pattern profile changed from a reverse to an ordinary taper and the pattern width increased. By AES analysis, nitrogen was detected in the pattern sidewall passivation layer when N2 gas was added. Optical emission spectroscopy of the plasma revealed that hydrogen was supplied from the decomposition product of the photoresist in RIE of aluminum with BCl3/Cl2. XPS, FT-IR and TDS analyses were carried out to study the structure of the passivation layer. Consequently, it was confirmed that nitrogen combined with hydrogen to form N–H bonds in NH4+, and that NH4+ coupled with Cl-, AlCl4- and SiF62- during aluminum and polysilicon RIE, respectively. It was also found that ammonium salts were deposited on the pattern sidewall, and played a major role in controlling the etching profile and pattern width.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::fa3e940000a3b6a4eb77c6684e98cf99 https://doi.org/10.1143/jjap.41.2220 Zobrazit plný text záznamu