DUAL LIGHT BEAM MODULATION OF PHOTOCARRIER LIFETIME IN INTRINSIC a-Si:H

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-597-C4-600 ◽  
Author(s):  
P. D. Persans ◽  
H. Fritzsche
Keyword(s):  
Light Beam ◽  
Beam Modulation

scholarly journals Effective Light Beam Modulation by Chirp IDT on a Suspended LiNbO3 Membrane for 3D Holographic Displays

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1218
Author(s):  
Yongbeom Lee ◽  
Keekeun Lee
Keyword(s):  
Light Beam ◽  
Focal Length ◽  
Incident Light ◽  
Coupling Efficiency ◽  
Input Power ◽  
Design Parameters ◽  
Holographic Display ◽  
Beam Modulation ◽  
Comsol Simulation ◽  
Holographic Displays

An acousto-optic (AO) holographic display unit based on a suspended waveguide membrane was developed. The AO unit consists of a wide bandwidth chirp interdigital transducer (IDT) on a 20 µm thick suspended crystalline 128° YX LiNbO3 membrane, a light blocker with a 20 µm hole near the entrance, and an active lens near the exit. The 20 µm thickness of the floating membrane significantly enhanced surface acoustic wave (SAW) confinement. The light blocker was installed in front of the AO unit to enhance the coupling efficiency of the incident light to the waveguide membrane and to remove perturbations to the photodetector during measurement at the exit region. The active lens was vertically attached to the waveguide sidewall to collect the diffracted beam without loss and to modulate the focal length in free space through the applied voltage. As SAWs were radiated from the IDT, a Bragg grating with periodic refractive indexes was formed along the waveguide membrane. The grating diffracted incident light. The deflection angle and phase, and the intensity of the light beam were controlled by the SAW frequency and input power, respectively. The maximum diffraction efficiency achieved was approximately 90% for a 400 MHz SAW. COMSOL simulation and coupling of mode modeling were performed to optimize design parameters and predict device performance.

Sample Preparation and Preservation for TEM Analysis of Copper Interconnect Integrated Circuit

2004 ◽  
Author(s):  
Qiang Gao ◽  
Mark Zhang ◽  
Ming Li ◽  
Chorng Niou ◽  
W.T. Kary Chien
Keyword(s):  
Integrated Circuit ◽  
Thermal Exposure ◽  
Ambient Atmosphere ◽  
Ion Milling ◽  
Tem Analysis ◽  
Single Beam ◽  
Copper Interconnect ◽  
Beam Modulation ◽  
Area Of Interest ◽  
Transmission Electron

Abstract This paper examines copper-interconnect integrated circuit transmission electron microscope (TEM) sample contamination. It investigates the deterioration of the sample during ion milling and storage and introduces prevention techniques. The paper discusses copper grain agglomeration issues barrier/seed step coverage checking. The high temperature needed for epoxy solidifying was found to be harmful to sidewall coverage checking of seed. Single beam modulation using a glass dummy can efficiently prevent contamination of the area of interest in a TEM sample during ion milling. Adoption of special low-temperature cure epoxy resin can greatly reduce thermal exposure of the sample and prevent severe agglomeration of copper seed on via sidewall. TEM samples containing copper will deteriorate when stored in ordinary driers and sulphur contamination was found at the deteriorated point on the sample. Isolation of the sample from the ambient atmosphere has been verified to be very effective in protecting the TEM sample from deterioration.

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