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Ali Shajii

Ali Shajii, Weston, MA US

Patent application numberDescriptionPublished
20110005922Methods and Apparatus for Protecting Plasma Chamber Surfaces - A method for creating a protective layer over a surface of an object comprising aluminum and magnesium for use in a semiconductor processing system, which includes oxidizing the surface of the object using a plasma electrolytic oxidation process. The method also includes generating a halogen-comprising plasma by exciting a gas comprising a halogen. The method also includes exposing the oxidized surface to the halogen-comprising plasma or excited gas.01-13-2011

Ali Shajii, Canton, MA US

Patent application numberDescriptionPublished
20080302652Particle Reduction Through Gas and Plasma Source Control - A system for producing excited gases for introduction to a semiconductor processing chamber. The system includes a plasma source for generating a plasma. The plasma source includes a plasma chamber and a gas inlet for receiving process gases from a gas source. A gas flow rate controller is coupled to the gas inlet for controlling an inlet flow rate of the process gases from the gas source to the plasma chamber via the gas inlet. The system includes a control loop for detecting a transition from a first process gas to a second process gas and for adjusting the inlet flow rate of the second process gas from about 0 sccm to about 10,000 sccm over a period of time greater than about 300 milliseconds to maintain transient heat flux loads applied by the plasma to an inner surface of the plasma chamber below a vaporization temperature of the plasma chamber.12-11-2008
20090095901CHEMICAL IONIZATION REACTION OR PROTON TRANSFER REACTION MASS SPECTROMETRY WITH A QUADRUPOLE MASS SPECTROMETER - A system and methods are described for generating reagent ions and product ions for use in a quadrupole mass spectrometry system. A microwave or high-frequency RF energy source ionizes particles of a reagent vapor to form reagent ions. The reagent ions enter a chamber, such as a drift chamber, to interact with a fluid sample. An electric field directs the reagent ions and facilitates an interaction with the fluid sample to form product ions. The reagent ions and product ions then exit the chamber under the influence of an electric field for detection by a quadrupole mass spectrometer module. The system includes various control modules for setting values of system parameters and analysis modules for detection of mass values for ion species during spectrometry and faults within the system.04-16-2009
20090095902CHEMICAL IONIZATION REACTION OR PROTON TRANSFER REACTION MASS SPECTROMETRY WITH A TIME-OF-FLIGHT MASS SPECTROMETER - A system, components thereof, and methods are described for time-of-flight mass spectrometry. A microwave or high-frequency RF energy source is used to ionize a reagent vapor to form reagent ions. The reagent ions enter a chamber and interact with a fluid sample to form product ions. The reagent ions and product ions are directed to a time-of-flight mass spectrometer module for detection and determination of a mass value for the ions. The time-of-flight mass spectrometer module can include an optical system and an ion beam adjuster for focusing, interrupting, or altering a flow of reagent and product ions according to a specified pattern. The time-of-flight mass spectrometer module can include signal processing techniques to collect and analyze an acquired signal, for example, using statistical signal processing, such as maximum likelihood signal processing.04-16-2009
20090320677PARTICLE TRAP FOR A PLASMA SOURCE - A particle trap for a remote plasma source includes a body structure having an inlet for coupling to a chamber of a remote plasma source and an outlet for coupling to a process chamber inlet. The particle trap for a remote plasma source also includes a gas channel formed in the body structure and in fluid communication with the body structure inlet and the body structure outlet. The gas channel can define a path through the body structure that causes particles in a gas passing from a first portion of the channel to strike a wall that defines a second portion of the gas channel at an angle relative to a surface of the wall. A coolant member can be in thermal communication with the gas channel.12-31-2009
20100219757Method and Apparatus of Providing Power to Ignite and Sustain a Plasma in a Reactive Gas Generator - Described are methods and apparatuses, including computer program products, for igniting and/or sustaining a plasma in a reactive gas generator. Power is provided from an ignition power supply to a plasma ignition circuit. A pre-ignition signal of the plasma ignition circuit is measured. The power provided to the plasma ignition circuit is adjusted based on the measured pre-ignition signal and an adjustable pre-ignition control signal. The adjustable pre-ignition control signal is adjusted after a period of time has elapsed.09-02-2010
20100231296Radio Frequency Power Delivery System - A system and method are provided for delivering power to a dynamic load. The system includes a power supply providing DC power having a substantially constant power open loop response, a power amplifier for converting the DC power to RF power, a sensor for measuring voltage, current and phase angle between voltage and current vectors associated with the RF power, an electrically controllable impedance matching system to modify the impedance of the power amplifier to at least a substantially matched impedance of a dynamic load, and a controller for controlling the electrically controllable impedance matching system. The system further includes a sensor calibration measuring module for determining power delivered by the power amplifier, an electronic matching system calibration module for determining power delivered to a dynamic load, and a power dissipation module for calculating power dissipated in the electrically controllable impedance matching system.09-16-2010
20100324743APPARATUS AND METHOD FOR PRESSURE FLUCTUATION INSENSITIVE MASS FLOW CONTROL - A mass flow controller includes a thermal mass flow sensor in combination with a pressure sensor to provide a mass flow controller that is relatively insensitive to fluctuations in input pressure. The pressure sensor and thermal sensor respectively provide signals to an electronic controller indicating the measured inlet flow rate and the pressure within the dead volume. The electronic controller employs the measured pressure to compensate the measured inlet flow rate and to thereby produce a compensated measure of the outlet flow rate, which may be used to operate a mass flow controller control valve.12-23-2010

Patent applications by Ali Shajii, Canton, MA US