Varian Semiconductor Equipment Associates, Inc.

Ziwei Fang

Vikram Singh

Matthew J Goeckner

Ludovic Godet

Harold M Persing

Bon-Woong Koo

Edmund Jacques Winder

Vassilis Panayotis Vourloumis

Richard Appel

Vincent Deno

George D Papasouliotis

Timothy J Miller

Richard S Muka

Steven Raymond Walther

Atul Gupta

Jay Thomas Scheuer

Jonathan Gerald England

Daniel Distaso

Bernard Lindsay

Edwin A Arevalo

Bon Woong Koo

Justin Tocco

Carleton F Ellis, Iii

Sung-Cheon Ko

Techniques for temperature-controlled ion implantation are disclosed. In one particular exemplary embodiment, the techniques may be realized as an apparatus for temperature-controlled ion implantation. The apparatus may comprise a platen to hold a wafer in a single-wafer process chamber during ion implantation, the platen including: a wafer clamping mechanism to secure the wafer onto the platen and to provide a predetermined thermal contact between the wafer and the platen, and one or more heating elements to pre-heat and maintain the platen in a predetermined temperature range above room temperature. The apparatus may also comprise a post-cooling station to cool down the wafer after ion implantation. The apparatus may further comprise a wafer handling assembly to load the wafer onto the pre-heated platen and to remove the wafer from the platen to the post-cooling station.

Techniques for temperature-controlled ion implantation

A plasma ion implantation system includes a process chamber, a source for producing a plasma in the process chamber, a platen for holding a substrate in the process chamber and a pulse source for generating implant pulses for accelerating ions from the plasma into the substrate. In one aspect, the system includes a plasma monitor configured to measure ion mass and energy in the process chamber and an analyzer configured to determine an operating condition of the system in response to the measured mass and energy. In another aspect, the system includes a data acquisition unit configured to acquire samples of the implant pulses and analyzer configured to determine an operating condition of the system based on the acquired samples.

Monitoring plasma ion implantation systems for fault detection and process control

A method to provide a dopant profile adjustment solution in plasma doping systems for meeting both concentration and junction depth requirements. Bias ramping and bias ramp rate adjusting may be performed to achieve a desired dopant profile so that surface peak dopant profiles and retrograde dopant profiles are realized. The method may include an amorphization step in one embodiment.

Profile adjustment in plasma ion implanter

A method and apparatus are directed to providing a dopant profile adjustment solution in plasma doping systems for meeting both concentration and junction depth requirements. Bias ramping and bias ramp rate adjusting may be performed to achieve a desired dopant profile so that shallow and abrupt junctions in vertical and lateral directions are realized that are critical to device scaling in plasma doping systems.

An in-situ ion sensor is disclosed for monitoring ion species in a plasma chamber. The ion sensor may comprise: a drift tube; an extractor electrode and a plurality of electrostatic lenses disposed at a first end of the drift tube, wherein the extractor electrode is biased to attract ions from a plasma in the plasma chamber, and wherein the plurality of electrostatic lenses cause at least one portion of the attracted ions to enter the drift tube and drift towards a second end of the drift tube within a limited divergence angle; an ion detector disposed at the second end of the drift tube, wherein the ion detector detects arrival times associated with the at least one portion of the attracted ions; and a housing for the extractor, the plurality of electrostatic lenses, the drift tube, and the ion detector, wherein the housing accommodates differential pumping between the ion sensor and the plasma chamber.

Technique for monitoring and controlling a plasma process

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.

A method for plasma ion implantation of a substrate includes providing a plasma ion implantation system having a process chamber, a source for producing a plasma in the process chamber, a platen for holding a substrate in the process chamber, an anode spaced from the platen, and a pulse source for generating implant pulses for accelerating ions from the plasma into the substrate. In one aspect, a parameter of an implant process is varied to at least partially compensate for undesired effects of interaction between ions being implanted and the substrate. For example, dose rate, ion energy, or both may be varied during the implant process. In another aspect, a pretreatment step includes accelerating ions from the plasma to the anode to cause emission of secondary electrons from the anode, and accelerating the secondary electrons from the anode to a substrate for pretreatment of the substrate.

Methods for stable and repeatable ion implantation

A technique for boron implantation is disclosed. In one particular exemplary embodiment, the technique may be realized by an apparatus for boron implantation. The apparatus may comprise a reaction chamber. The apparatus may also comprise a source of pentaborane coupled to the reaction chamber, wherein the source is capable of supplying a substantially pure form of pentaborane into the reaction chamber. The apparatus may further comprise a power supply that is configured to energize the pentaborane in the reaction chamber sufficiently to produce a plasma discharge having boron-bearing ions.

Technique for boron implantation

Plasma doping apparatus includes a plasma doping chamber, a platen mounted in the plasma doping chamber for supporting a workpiece such as a semiconductor wafer, a source of ionizable gas coupled to the chamber, an anode spaced from the platen and a pulse source for applying voltage pulses between the platen and the anode. The voltage pulses produce a plasma having a plasma sheath in the vicinity of the workpiece. The voltage pulses accelerate positive ions across the plasma sheath toward the platen for implantation into the workpiece. The plasma doping apparatus includes at least one Faraday cup positioned adjacent to the platen for collecting a sample of the positive ions accelerated across the plasma sheath. The sample is representative of the dose of positive ions implanted into the workpiece. The Faraday cup may include a multi-aperture cover for reducing the risk of discharge within the interior chamber of the Faraday cup. The Faraday cup may be configured to produce a lateral electric field within the interior chamber for suppressing escape of electrons, thereby improving measurement accuracy.

Dose monitor for plasma doping system

A pulsed plasma doping system separates the plasma ignition function from the ion implantation function. An ignition voltage pulse is supplied to an ionizable gas and an implantation voltage pulse is applied to the target. The implantation voltage pulse can be generated from the ignition voltage pulse or can be generated separately from the ignition voltage pulse. Ions may be implanted in the target at an energy level that is below the Paschen curve for the system.

Method and apparatus for low voltage plasma doping using dual pulses

A plasma doping apparatus includes a hollow cathode to increase throughput and uniformity of ion implantations in a target. The hollow cathode is located adjacent an anode and a target cathode on which a target is placed. An ionizable gas is provided in a space between the anode and the target cathode. The space in which the ionizable gas is provided is surrounded by the hollow cathode. The hollow cathode has either a circular or rectangular cross-section.

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Beverly, MA, United States of America

Ziwei Fang