Varian Semiconductor Equipment Associates, Inc.

Bernard Lindsay

Ludovic Godet

Timothy J Miller

Vikram Singh

George D Papasouliotis

Kamal Hadidi

Bon-Woong Koo

Steven Raymond Walther

Christopher J Leavitt

Ziwei Fang

Rajesh Dorai

Helen L Maynard

Deven M Raj

Vassilis Panayotis Vourloumis

Techniques for plasma processing a substrate are disclosed. In one particular exemplary embodiment, the technique may be realized with a method comprising introducing a feed gas proximate to a plasma source, where the feed gas may comprise a first and second species, where the first and second species have different ionization energies; providing a multi-level RF power waveform to the plasma source, where the multi-level RF power waveform has at least a first power level during a first pulse duration and a second power level during a second pulse duration, where the second power level may be different from the first power level; ionizing the first species of the feed gas during the first pulse duration; ionizing the second species during the second pulse duration; and providing a bias to the substrate during the first pulse duration.

Techniques for plasma processing a substrate

Plasma processing with enhanced charge neutralization and process control is disclosed. In accordance with one exemplary embodiment, the plasma processing may be achieved as a method of plasma processing a substrate. The method may comprise providing the substrate proximate a plasma source; applying to the plasma source a first RF power level during a first period and a second RF power level during a second period, the first and second RF power levels being greater than zero RF power level, wherein the second RF power level is greater than the first RF power level; generating with the plasma source a first plasma during the first period and a second plasma during the second period; and applying to the substrate a first bias voltage during the first period and a second bias voltage during the second period, wherein the first voltage has more negative potential than the second voltage.

Plasma processing with enhanced charge neutralization and process control

A method is disclosed for adjusting the composition of plasmas used in plasma doping, plasma deposition and plasma etching techniques. The disclosed method enables the plasma composition to be controlled by modifying the energy distribution of the electrons present in the plasma. Energetic electrons are produced in the plasma by accelerating electrons in the plasma using very fast voltage pulses. The pulses are long enough to influence the electrons, but too fast to affect the ions significantly. Collisions between the energetic electrons and the constituents of the plasma result in changes in the plasma composition. The plasma composition can then be optimized to meet the requirements of the specific process being used. This can entail changing the ratio of ion species in the plasma, changing the ratio of ionization to dissociation, or changing the excited state population of the plasma.

System and method for selectively controlling ion composition of ion sources

A plasma processing apparatus includes a process chamber, a platen positioned in the process chamber for supporting a workpiece, a source configured to generate a plasma in the process chamber having a plasma sheath adjacent to the front surface of the workpiece, and an insulating modifier. The insulting modifier is configured to control a shape of a boundary between the plasma and the plasma sheath so a portion of the shape of the boundary is not parallel to a plane defined by a front surface of the workpiece facing the plasma. Controlling the shape of the boundary between the plasma and the plasma sheath enables a large range of incident angles of particles striking the workpiece to be achieved.

Plasma processing apparatus

A plasma processing apparatus includes a process chamber, a platen positioned in the process chamber for supporting a workpiece, a source configured to generate a plasma in the process chamber, and a monitoring system including an ion mobility spectrometer configured to monitor a condition of the plasma. A monitoring method including generating a plasma in a process chamber of a plasma processing apparatus, supporting a workpiece on a platen in the process chamber, and monitoring a condition of the plasma with an ion mobility spectrometer is also provided.

Technique for monitoring and controlling a plasma process with an ion mobility spectrometer

Techniques for detecting wafer charging in a plasma processing system are disclosed. In one particular exemplary embodiment, the techniques may be realized as an apparatus for detecting wafer charging in a plasma processing system. The apparatus may comprise a plasma chamber to produce a plasma discharge above a wafer in the plasma chamber. The apparatus may also comprise a biasing circuit to bias the wafer to draw ions from the plasma discharge towards the wafer. The apparatus may further comprise a detection mechanism to detect charge buildup on the wafer by measuring an electric field in one or more designated locations near a top surface of the wafer.

Techniques for detecting wafer charging in a plasma processing system

A method of controlling a plasma doping process using a time-of-flight ion detector includes generating a plasma comprising dopant ions in a plasma chamber proximate to a platen supporting a substrate. The platen is biased with a bias voltage waveform having a negative potential that attracts ions in the plasma to the substrate for plasma doping. A spectrum of ions present in the plasma is measured as a function of ion mass with a time-of-flight ion detector. The total number ions impacting the substrate is measured with a Faraday dosimetry system. An implant profile is determined from the measured spectrum of ions. An integrated dose is determined from the measured total number of ions and the calculated implant profile. At least one plasma doping parameter is modified in response to the calculated integrated dose.

Closed loop control and process optimization in plasma doping processes using a time of flight ion detector

A time-of-flight ion sensor for monitoring ion species in a plasma includes a housing. A drift tube is positioned in the housing. An extractor electrode is positioned in the housing at a first end of the drift tube so as to attract ions from the plasma. A plurality of electrodes is positioned at a first end of the drift tube proximate to the extractor electrode. The plurality of electrodes is biased so as to cause at least a portion of the attracted ions to enter the drift tube and to drift towards a second end of the drift tube. An ion detector is positioned proximate to the second end of the drift tube. The ion detector detects arrival times associated with the at least the portion of the attracted ions.

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Danvers, MA, United States of America

Bernard Lindsay