Titanium-based high-K dielectric films

US8551851B2 · kind B2 · utility

Assignee

• INTERMOLECULAR, INC. · US

Inventors

• Hanhong Chen · Milpitas, US
• Pragati Kumar · Santa Clara, US
• Sunil Shanker · Santa Clara, US
• Edward Haywood · San Jose, US
• Sandra G. Malhotra · San Jose, US
• Imran Hashim · Saratoga, US
• Nobi Fuchigami · Santa Clara, US
• Prashant B. Phatak · San Jose, US
• Monica Mathur · San Jose, US

Key dates

• Filing date: May 4, 2011
• Grant date: Oct 8, 2013
• Expiry date: Jan 20, 2032

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/435
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

This disclosure provides (a) methods of making an oxide layer (e.g., a dielectric layer) based on titanium oxide, to suppress the formation of anatase-phase titanium oxide and (b) related devices and structures. A metal-insulator-metal (“MIM”) stack is formed using an ozone pretreatment process of a bottom electrode (or other substrate) followed by an ALD process to form a TiO2 dielectric, rooted in the use of an amide-containing precursor. Following the ALD process, an oxidizing anneal process is applied in a manner is hot enough to heal defects in the TiO2 dielectric and reduce interface states between TiO2 and electrode; the anneal temperature is selected so as to not be so hot as to disrupt BEL surface roughness. Further process variants may include doping the titanium oxide, pedestal heating during the ALD process to 275-300 degrees Celsius, use of platinum or ruthenium for the BEL, and plural reagent pulses of ozone for each ALD process cycle. The process provides high deposition rates, and the resulting MIM structure has substantially no x-ray diffraction peaks associated with anatase-phase titanium oxide.