A method for controlling an exhaust after-treatment system connected to a diesel engine via a gas passage and having a diesel oxidation catalyst (DOC) and a diesel-exhaust-fluid (DEF) injector arranged downstream of the DOC and upstream of a selective catalytic reduction catalyst (SCR) includes detecting a flow of exhaust gas emitted by the engine into the gas passage. The method also includes detecting a level of nitrogen oxides (NO.sub.x) in the exhaust gas downstream of the SCR. The method additionally includes activating the DEF injector for a period of time to reduce the level of NO.sub.x to a predetermined NO.sub.x value. Furthermore, the method includes regulating an injection of fuel upstream of the DOC to clean the DEF injector via a stream of superheated exhaust gas if the period of time used to reduce the level of NO.sub.x to the predetermined NO.sub.x value is greater than a predetermined threshold value.

Embodiments of the present invention provide an apparatus and methods for detecting an endpoint for a cleaning process. In one example, a method of determining a cleaning endpoint includes performing a cleaning process in a plasma processing chamber, directing an optical signal to a surface of a shadow frame during the cleaning process, collecting a return reflected optical signal reflected from the surface of the shadow frame, determining a change of reflectance intensity of the return reflected optical signal as collected, and determining an endpoint of the cleaning process based on the change of the reflected intensity. In another example, an apparatus for performing a plasma process and a cleaning process after the plasma process includes an optical monitoring system coupled to a processing chamber, the optical monitoring system configured to direct an optical beam light to a surface of a shadow frame disposed in the processing chamber.

A method for controlling an exhaust after-treatment system connected to a diesel engine via a gas passage and having a diesel oxidation catalyst (DOC) and a diesel-exhaust-fluid (DEF) injector arranged downstream of the DOC and upstream of a selective catalytic reduction catalyst (SCR) includes detecting a flow of exhaust gas emitted by the engine into the gas passage. The method also includes detecting a level of nitrogen oxides (NO.sub.x) in the exhaust gas downstream of the SCR. The method additionally includes activating the DEF injector for a period of time to reduce the level of NO.sub.x to a predetermined NO.sub.x value. Furthermore, the method includes regulating an injection of fuel upstream of the DOC to clean the DEF injector via a stream of superheated exhaust gas if the period of time used to reduce the level of NO.sub.x to the predetermined NO.sub.x value is greater than a predetermined threshold value.

Implementations described herein generally relate to methods and apparatus for in-situ removal of unwanted deposition buildup from one or more interior surfaces of a semiconductor substrate-processing chamber. In one implementation, the method comprises forming a reactive fluorine species from a fluorine-containing cleaning gas mixture. The method further comprises delivering the reactive fluorine species into a processing volume of a substrate-processing chamber. The processing volume includes one or more aluminum-containing interior surfaces having unwanted deposits formed thereon. The method further comprises permitting the reactive fluorine species to react with the unwanted deposits and aluminum-containing interior surfaces of the substrate-processing chamber to form aluminum fluoride. The method further comprises exposing nitrogen-containing cleaning gas mixture to in-situ plasma to form reactive nitrogen species in the processing volume. The method further comprises permitting the reactive nitrogen species to react with the ammonium fluoride to convert the aluminum fluoride to aluminum nitride.

Described herein are architectures, platforms and methods for acquiring optical emission spectra from an optical emission spectroscopy system by flowing a dry cleaning gas into a plasma processing chamber of the plasma processing system and igniting a plasma in the plasma processing chamber to initiate the waferless dry cleaning process.

The present invention discloses an on-line cleaning control system and method for carbon deposits in a direct injection engine fuel system. The system comprises a cleaner tank, a cleaner input pipeline, an electromagnetic flow controller and a control circuit. A liquid transfer pump is in series connection with a pipeline of the cleaner input pipeline and the cleaner tank; when the conditions that fuel is injected through a fuel injector of the engine, the temperature of a three-way catalytic converter is lower than 800 C., the rotational speed of the engine is greater than 1200 rpm and the cleaning time is shorter than set cleaning time are met, the control circuit starts a cleaning working procedure to inject a cleaner into an intake manifold of the engine. According to the present invention, the liquid transfer pump is used for actively injecting the cleaner into an intake valve of the engine, and besides, the optimal cleaning condition of the engine is controlled; a starting switch can be arranged in a cab so that on-line cleaning for the carbon deposits in the intake valve and a combustion chamber of the engine is performed actively according to the usage state of an automobile; and also, by receiving a mileage signal and presetting a mileage starting value in the controller, on-line cleaning for the carbon deposits in the intake valve and the combustion chamber of the engine can be performed automatically and periodically in accordance with mileages.

A method for cleaning a substrate is provided. The method includes providing a substrate. Metal compound residues are formed over the substrate. The method includes exposing the substrate to an organic plasma to volatilize the metal compound residues. The organic plasma is generated from a gas. The gas includes an organic gas, and the organic gas is made of a hydrocarbon compound or an alcohol compound.

A method for cleaning a plasma processing chamber is provided. The method includes introducing an organic gas into a plasma processing chamber. The organic gas includes an organic compound including carbon and hydrogen. The method includes generating an organic plasma by exciting the organic gas. The organic plasma reacts with metal compound residues over an interior surface of the plasma processing chamber to volatilize the metal compound residues into a gaseous metal compound. The method includes removing the gaseous metal compound from the plasma processing chamber.