XPS/AES investigation of cross contamination in a plasma etcher

Abstract

Oxidation of cobalt at room temperature, studied by combined static SIMS, static AES, XPS, and work function investigations Quasisimultaneous SIMS, AES, and XPS investigations of the oxidation of Mo, Ti, and Co in the monolayer range J. Vac. Sci. Technol. 15, 506 (1978); 10.1116/1.569456 Quasisimultaneous SIMS-AES-XPS investigation of the oxidation of Ti in the monolayer range Appl.Although dedication of plasma etching equipment strictly to a single process is becoming a common practice in IC labs, a large number of older plasma systems (especially the barrel type) were designed and are still used for multiple processes such as thin film etching in CF 4 based plasma and photoresist striping in pure oxygen plasma. An investigation of a cross contamination effect is reported here. Silicon wafers coated with aluminum and exposed to a simulated oxygen plasma resist strip process were analyzed using Auger electron spectroscopy and x-ray photoelectron spectroscopy. Relatively large amounts of carbon and fluorine were found to be present on the wafer surfaces. Wafers exposed to wet chemical treatments were analyzed for comparison. The C and F contamination is believed to be due to redeposition of a fluorocarbon compound on the wafer surface originating from the chamber walls, etc. ESCA examination of the samples resulted in similar observations but the chemical identification ofthe contamination could not be made.

Electron Tunneling and X-Ray Photoelectron Spectroscopy Studies of the Superconducting Properties of Nitrogen-Doped Niobium Resonator Cavities

“…2(a) show that sputtering with 1 keV Ar ions shifts spectral weight from Nb 2 O 5 to lower Nb oxidation states. Ar ion sputtering of oxidized Nb is believed to both preferentially remove oxygen from Nb 2 O 5 and diffuse oxygen into bulk Nb 60 , thickening the lower oxidation state layers (presented schematically in Fig. 2(b)).…”

Effect of surface modification on the properties of plasma‐polymerized hexamethyldisiloxane thin films

“…For the sample S‐SF 6 , the incorporation of F atoms in the film structure is confirmed with a concentration of about 8.8 At%; a decrease of both O and Si concentrations of about 24% and 25%, respectively, can be noticed also, which indicates that F atoms mainly attacks the bonds containing Si and O. For sample S‐O 2 , the oxidation of the O 2 plasma–treated pp‐HMDSO film is revealed by the increase of O At% (of about 8%) and the decrease of C At% (of about 17%); the appearance of fluorine after oxygen plasma treatment, as a contaminant, is a result of oxygen plasma ashing of already deposited fluorinated compounds in the plasma chamber . Indeed, our reactor is used for multiple plasma processing purposes such as deposition of organosilicon thin films and surface materials modification using SF 6 , Ar, N 2 , and O 2 gases.…”

“…The used plasma-polymerized hexamethyldisiloxane (pp-HMDSO) metal-insulator-metal (MIM) structure for I-V characteristics measurements is a result of oxygen plasma ashing of already deposited fluorinated compounds in the plasma chamber 35,36. Indeed, our reactor is used for multiple plasma processing purposes such as deposition of organosilicon thin films and surface materials modification usingSF 6 , Ar, N 2 , and O 2 gases.…”

Threshold Levels and Effects of Feed Gas Impurities on Plasma Etching Processes

“…Chlorine-containing discharges are particularly sensitive, since C1 loss by surface recombination can be significant and can affect the discharge chemistry. Such cross-contamination by chamber walls can be a problem when an etcher is used for multiple processes (11,12). Atomic chlorine loss can also cause non-uniformity in Cl-based etching processes.…”