Raman spectroscopy as a real-time in situ sensor for biopharma

A method for real-time determination of the percent cure of epoxies via in situ fiber-optic Raman spectroscopy has been developed. This method utilizes a probe design developed for real-time monitoring of polymer curing and multivariate analysis to interpret the data and determine percent cure. This method was demonstrated to be reliable to ±0.54% of cure in laboratory samples over a 50–99% cure range. A preliminary study measuring cure percentage in an industrial, glass-reinforced composite has been shown to be reliable to ±0.82% in the 40–90% cure range.

Download Full-text

Real-Time, In Situ Sensor for Control of Ammonia Slip in SCR Installations

10.2172/921941 ◽

2005 ◽

Author(s):

James Daly

Keyword(s):

Real Time ◽

Ammonia Slip ◽

In Situ Sensor

Download Full-text

Real-time in situ observations of reaction and transport phenomena during silicate glass corrosion by fluid-cell Raman spectroscopy

Nature Materials ◽

10.1038/s41563-019-0293-8 ◽

2019 ◽

Vol 18 (4) ◽

pp. 342-348 ◽

Cited By ~ 19

Author(s):

Thorsten Geisler ◽

Lars Dohmen ◽

Christoph Lenting ◽

Moritz B. K. Fritzsche

Keyword(s):

Raman Spectroscopy ◽

Real Time ◽

Silicate Glass ◽

Transport Phenomena ◽

Glass Corrosion ◽

In Situ Observations ◽

Fluid Cell

Download Full-text

In Situ Spectroscopic Ellipsometry for the Real Time Process Control of Plasma Etching of Silicon Nitride

MRS Proceedings ◽

10.1557/proc-591-263 ◽

1999 ◽

Vol 591 ◽

Author(s):

I. G. Rosen ◽

T. Parent ◽

B. Fidan ◽

A. Madhukar

Keyword(s):

Silicon Nitride ◽

Real Time ◽

Plasma Etching ◽

Spectroscopic Ellipsometry ◽

Etch Rate ◽

Polarization State ◽

Non Invasive ◽

Silicon Nitride Films ◽

In Situ Sensor

ABSTRACTSpectroscopic ellipsometry (SE) is a commonly used non-destructive, non-invasive in-situ sensor for dry etching. SE measures the change in the polarization state of light reflected from a surface. Sample thickness is obtained by fitting a model to the experimental ellipsometry data. In this paper we describe the design, testing and evaluation of an SE based adaptive real time feedback controller for etch rate regulation in CF4/O2 plasma etching of silicon nitride films. The feedback variable is the current etch rate as determined from the in-situ SE measurements of the film's thickness. The controller compensates for drifts in etch rate which occur during a given etch, and adaptively adjusts for the run-to-run variability inherent to plasma processing. Experimental results are presented and discussed.

Download Full-text