Spectroscopic ellipsometry (SE) based real-time control of CF/sub 4//O/sub 2/ plasma etching of silicon nitride

2000 ◽  
Author(s):  
B. Fidan ◽  
T. Parent ◽  
G. Rosen ◽  
A. Madhukar
Keyword(s):  
Silicon Nitride ◽  
Real Time ◽  
Plasma Etching ◽  
Spectroscopic Ellipsometry ◽  
Real Time Control ◽  
Time Control

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

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.

Real-time control of HgCdTe growth by organometallic vapor phase epitaxy using spectroscopic ellipsometry

1995 ◽  
Vol 24 (9) ◽  
pp. 1087-1091 ◽  
Author(s):  
Srikanteswara Dakshina Murthy ◽  
Ishwara Bhat ◽  
Blaine Johs ◽  
Shakil Pittal ◽  
Ping He
Keyword(s):  
Real Time ◽  
Vapor Phase ◽  
Spectroscopic Ellipsometry ◽  
Vapor Phase Epitaxy ◽  
Organometallic Vapor Phase Epitaxy ◽  
Real Time Control ◽  
Time Control

In-Situ Spectroscopic Ellipsometry and Optical Emission Studies of CF4/O2 Plasma Etching of Silicon Nitride

1999 ◽  
Vol 569 ◽  
Author(s):  
T. Parent ◽  
J. Tie ◽  
A. Madhukar
Keyword(s):  
Silicon Nitride ◽  
Real Time ◽  
Plasma Etching ◽  
Spectroscopic Ellipsometry ◽  
Etch Rate ◽  
Electron Cyclotron Resonance ◽  
Optical Emission ◽  
Sample Introduction ◽  
Chamber Pressure

ABSTRACTElectron cyclotron resonance (ECR) CF4/ 02 plasma etching of silicon nitride (SixNy) deposited by plasma enhanced chemical vapor deposition (PECVD) has been examined in-situ by means of spectroscopic ellipsometry (SE) and optical emission (OE). The observed real-time etchrate and the relative intensity of emission of atomic fluorine at 703.7 nm are measured simultaneously and both are found to change with time during the etch in a reproducible manner. The evolution of the real-time etch rate and the fluorine emission intensity depends on the machine input settings and the extent to which the chamber has been exposed to CF4/ 02 plasma prior to sample introduction. In general the initial 10 to 40 seconds of etching reveal a rapid increase in the etch rate, the remainder of the etch exhibiting an etch rate which typically increases gradually until the etch is stopped. This variation in etch behavior with time during the etch process complicates the task of precisely and reliably etching ultrathin (< 50 nm) films, necessitating real-time control based upon in-situ sensors, the end objective of this work. The dependence of the evolution of the SixNy etch rate on microwave power, chamber pressure, and gas in-flow rate is presented and the implications of these dependencies on the implementation of real-time feedback control are discussed.

Application of spectroscopic ellipsometry for real-time control of CdTe and HgCdTe growth in an OMCVD system

1995 ◽  
Vol 24 (5) ◽  
pp. 445-449 ◽  
Author(s):  
S. Dakshina Murthy ◽  
I. B. Bhat ◽  
B. Johs ◽  
S. Pittal ◽  
P. He
Keyword(s):  
Real Time ◽  
Spectroscopic Ellipsometry ◽  
Real Time Control ◽  
Time Control

A Real Time Control Architecture for Continuously Managing Patients in a Care Unit

1995 ◽  
Vol 34 (05) ◽  
pp. 475-488
Author(s):  
B. Seroussi ◽  
J. F. Boisvieux ◽  
V. Morice
Keyword(s):  
Real Time ◽  
Linear Time ◽  
Treatment Plan ◽  
Control Architecture ◽  
Real Time Control ◽  
Time Representation ◽  
Time Control ◽  
Continuous Support ◽  
Definition Of ◽  
Computerized System

Abstract:The monitoring and treatment of patients in a care unit is a complex task in which even the most experienced clinicians can make errors. A hemato-oncology department in which patients undergo chemotherapy asked for a computerized system able to provide intelligent and continuous support in this task. One issue in building such a system is the definition of a control architecture able to manage, in real time, a treatment plan containing prescriptions and protocols in which temporal constraints are expressed in various ways, that is, which supervises the treatment, including controlling the timely execution of prescriptions and suggesting modifications to the plan according to the patient’s evolving condition. The system to solve these issues, called SEPIA, has to manage the dynamic, processes involved in patient care. Its role is to generate, in real time, commands for the patient’s care (execution of tests, administration of drugs) from a plan, and to monitor the patient’s state so that it may propose actions updating the plan. The necessity of an explicit time representation is shown. We propose using a linear time structure towards the past, with precise and absolute dates, open towards the future, and with imprecise and relative dates. Temporal relative scales are introduced to facilitate knowledge representation and access.

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