Abstract: The present invention provides a method for controlling pressure in a chamber during a time division multiplexed process. A throttle valve is positioned based on an open-loop pressure control algorithm within at least one step of the time division multiplexed etch process. A pressure response of the step is evaluated and compared to a desired pressure response. The throttle valve is then positioned through a proportional, integral and derivative controller step to step of the time division multiplexed etch process based on the evaluation to the desired pressure response.

Abstract: The present invention provides a method for controlling pressure in a vacuum chamber during a time division multiplexed process. A throttle valve is pre-positioned and held for a predetermined period of time. A process gas is introduced into the vacuum chamber during the associated plasma step (deposition or etching) of the silicon wafer. At the end of the predetermined period of time, the process gas continues to flow with the throttle valve being released from the set position. At this point, the throttle valve is regulated through a proportional derivative and integral control for a period that lasts the remaining time of the associated plasma step.

Abstract: The present invention provides a method and an apparatus for establishing endpoint during an alternating cyclical etch process or time division multiplexed process. A substrate is placed within a plasma chamber and subjected to an alternating cyclical process having an etching step and a deposition step. A variation in plasma emission intensity is monitored using known optical emission spectrometry techniques. An amplitude information is extracted from a complex waveform of the plasma emission intensity using an envelope follower algorithm. The alternating cyclical process is discontinued when endpoint is reached at a time that is based on the monitoring step.

Abstract: The present invention provides a method and an apparatus for etching a photolithographic substrate. The photolithographic substrate is placed on a support member in a vacuum chamber. A processing gas for etching a material from the photolithographic substrate is introduced into the vacuum chamber, and a plasma is generated. An RF bias is supplied to the support member in the vacuum chamber through an RF bias frequency generator at or below the ion transit frequency. Exposed material is etched from the photolithographic substrate with improved CD Etch Linearity and CD Etch Bias since the low frequency bias allows the developed charge on the photolithographic substrate, generated by the plasma, to dissipate.

Abstract: An improved method for determining endpoint of a time division multiplexed process by monitoring an identified region of a spectral emission of the process at a characteristic process frequency. The region is identified based upon the expected emission spectra of materials used during the time division multiplexed process. The characteristic process frequency is determined based upon the duration of the steps in the time division multiplexed process. Changes in the magnitude of the monitored spectra indicate the endpoint of processes in the time division multiplexed process and transitions between layers of materials.

Abstract: An improved method for introducing gases into an alternating plasma etching/deposition chamber is provided by the present invention. To minimize the introduction of pressure pulses into the alternating etching/deposition chamber when the deposition and etchant gas supplies are switched on and off, a mass flow controller is used to provide a relatively constant flow of gas. A gas bypass or a gas exhaust is provided such that when a gas inlet to the alternating etching/deposition chamber is closed an alternative path is provided for the flow of gas from the mass flow controller. The provision of a bypass or exhaust maintains the pressure of the gas received from the mass flow controller at a substantially constant level. The elimination or minimization of a pressure pulse of the gas helps increase the smoothness of the walls of high aspect ratio features etched in a silicon substrate in the alternating etching/deposition chamber.

Abstract: A method of preventing notching during a cyclical etching and deposition of a substrate with an inductively coupled plasma source is provided by the present invention. In accordance with the method, the inductively coupled plasma source is pulsed to prevent charge build up on the substrate. The off state of the inductively coupled plasma source is selected to be long enough that charge bleed off can occur, but not so long that reduced etch rates result due to a low duty cycle. The pulsing may be controlled such that it only occurs when the substrate is etched such that an insulating layer is exposed. A bias voltage may also be provided to the insulating layer and the bias voltage may be pulsed in phase or out of phase with the pulsing of the inductively coupled plasma source.

Abstract: An improved method for etching a substrate that reduces the formation of pillars is provided by the present invention. In accordance with the method, the residence time of an etch gas utilized in the process is decreased and the power of an inductively coupled plasma source used to dissociate the etch gas is increased. A low bias RF voltage is provided during the etching process. The RF bias voltage is ramped between different bias levels utilized during the etch process. An inductively coupled plasma confinement ring is utilized to force the reactive species generated in the inductively coupled plasma source over the surface of the substrate. These steps reduce or eliminate the formation of pillars during the etching process.

Abstract: An apparatus, typically a sealing member extending around the periphery of a substrate support or chuck, seals an individual substrate with respect to a substrate support, typically in a processing chamber. The seal is of a corrugated shape, that enhances clamping forces, typically from electrostatic or mechanical clamps, to provide a seal between it and the substrate, for example a wafer.

Abstract: Methods and apparatus for compensating for temperature variations in acousto-optic devices are described. An acousto-optic tunable device according to the invention features an acousto-optic substrate having an acoustic wave transducer positioned on the acousto-optic substrate. A temperature sensor is positioned in thermal communication with the acousto-optic substrate. The temperature sensor generates an electrical signal that is related to a temperature of the acousto-optic substrate. A processor generates a control signal in response to the electrical signal generated by the temperature sensor. An oscillator receives the control signal and a frequency of the oscillator is changed in response to the control signal in order to maintain phase-matching criteria of the acousto-optic tunable device as the temperature of the acousto-optic substrate changes.

Abstract: An acousto-optic tunable filter that includes a polarization beamsplitter, a multi-segment interaction region and a polarization beam combiner is described. The polarization beamsplitter generates a first and a second polarized optical signal. The multi-segment optical interaction region includes a first optical interaction region and a first acoustic wave generator that generates acoustic waves in the first optical interaction region. The multi-segment optical interaction region also includes a second optical interaction region that is non-collinear relative to the first optical interaction region and a second acoustic wave generator that generates acoustic waves in the second optical interaction region. Optical signals that are phase-matched to the acoustic waves are mode-converted in response to the acoustic waves. The acousto-optic tunable filter also includes a polarization beam combiner that generates both a mode-converted optical signal and a non-mode-converted optical signal.

Abstract: A deposition system is described. The deposition system includes a deposition source that generates deposition flux comprising neutral atoms and molecules. A shield defining an aperture is positioned in the path of the deposition flux. The shield passes the deposition flux through the aperture and substantially blocks the deposition flux from propagating past the shield everywhere else. A substrate support is positioned adjacent to the shield. A dual-scanning system scans the substrate support relative to the aperture with a first and a second motion.

Abstract: An improved method for etching a substrate that reduces the formation of pillars is provided by the present invention. In accordance with the method, the residence time of an etch gas utilized in the process is decreased and the power of an inductively coupled plasma source used to dissociate the etch gas is increased. A low bias RF voltage is provided during the etching process. The RF bias voltage is ramped between different bias levels utilized during the etch process. An inductively coupled plasma confinement ring is utilized to force the reactive species generated in the inductively coupled plasma source over the surface of the substrate. These steps reduce or eliminate the formation of pillars during the etching process.

Abstract: A method of determining thickness and refractive index of an optical thin film is described. The method includes generating a diagnostic light beam having a first and a second wavelength. The method also includes measuring unattenuated light intensities at the first and the second wavelength of the diagnostic light beam. The method also includes measuring attenuated light intensities at the first and the second wavelength of the diagnostic light beam after transmission through the optical thin film. A null light intensity for the diagnostic light beam at the first and second wavelength is also determined. A first and second normalized intensity function is determined using the measured unattenuated light intensities, the measured attenuated light intensities, and the measured null light intensities. The thickness and refractive index of the optical thin film is then determined by solving the first and second normalized intensity function for thickness and refractive index.

Abstract: A method for forming an etching mask structure on a substrate includes etching the substrate, laterally expanding the etching mask structure, and depositing a self-aligned metal layer that is aligned to the originally masked area. The etching can be isotropic or anisotropic. The self-aligned metal layer can be distanced from the original etching masked area based on the extent of the intentionally laterally expanded etching mask layer. Following metal deposition, the initial mask structure can be removed, thus lifting off the metal atop it. The etching mask structure can be a resist and can be formed using conventional photolithography materials and techniques and can have nearly vertical sidewalls. The lateral extension can include a silylation technique of the etching mask layer following etching. The above method can be utilized to form bipolar, hetero-bipolar, or field effect transistors.

Abstract: A method and apparatus for fabricating a submicrometer structure. The method incorporates a sputtering process to deposit an electromagnetic material from a seedlayer onto a vertical sidewall. The vertical sidewall is subsequently removed, leaving a free-standing pole-tip. The resulting structure formed can have a a width of less than 0.3 micrometers, if desired. This structure can be used as a magnetic pole of a thin film head (“TFH”) for a data storage device.

Abstract: An embedded attenuated phase shift mask (“EAPSM”) includes an etch stop layer that can be plasma etched in a process that is highly selective to the underlying quartz substrate. Selectivity to the underlying quartz maintains a desired 180 degree phase shift uniformly across the active mask area. Conventional plasma etching techniques can be utilized without damage to the underlying quartz substrate. Alternatively, the etch stop layer comprises a transparent material that can remain intact in the mask structure.

Abstract: A method and apparatus for fabricating an electroplating mask for the formation of a miniature magnetic pole tip structure. The method incorporates a silylation process to silylate photoresist after creating a photoresist cavity or trench in the electroplating mask. The silylation process is performed after a dry etch of the photoresist. Alternatively, silylation is performed after a lithographic patterning of the trench. As a result of chemical biasing, the vertical side walls of the photoresist layer shift inward creating a narrower trench. The resulting structure formed after electroplating has a width of less than 0.3 micrometers. This structure can be used as a magnetic pole of a thin film head (“TFH”) for a data storage device.

Abstract: A differentially pumped deposition system is described that includes a deposition source, such as a magnetron sputtering source, that is positioned in a first chamber. The deposition source generates deposition flux comprising neutral atoms and molecules. A shield that defines an aperture is positioned in the path of the deposition flux. The shield passes the deposition flux though the aperture and substantially blocks the deposition flux from propagating past the shield everywhere else. A substrate support is positioned in the second chamber adjacent to the shield. The pressure in the second chamber is lower than a pressure in the first chamber. A dual-scanning system scans the substrate support relative to the aperture with a first and a second motion, thereby improving uniformity of the deposited thin fill.

Abstract: An embedded attenuated phase shift mask (“EAPSM”) includes an etch stop layer that can be plasma etched in a process that is highly selective to the underlying quartz substrate. Selectivity to the underlying quartz maintains a desired 180 degree phase shift uniformly across the active mask area. Conventional plasma etching techniques can be utilized without damage to the underlying quartz substrate. Alternatively, the etch stop layer comprises a transparent material that can remain intact in the mask structure.