Texas Instruments Corporation

Edwin G Millis

Samuel J Wood, Jr

Leonard W Foster

Thomas C Bimer

Samuel R Shortes

Wayne G Fisher

Robert A Bowling

Malvern L Creps

Alton D Lewis

A vacuum storage cassette for semiconductor wafers has one or more valves to allow the cassette to be evacuated, backfilled, and opened to the surround atmosphere and resealed without the need for a vacuum load-lock chamber.

Vented vacuum semiconductor wafer cassette

A system and method for determining the pattern development endpoint of a photoresist polymer during spin/spray processing of a semiconductor wafer utilizes the optical transmission of the waster developer liquid during the pattern develop process to determine when the developing is completed.

Process and system for determining photoresist development endpoint by

An optical analyzer and a developer recirculation system is used to determine the amount of photoresist polymer dissolved in a quantity of developer solution and the sensor output signal is utilized by a control computer to control the admission of fresh developer solution to replace used developer and maintain a fixed level of dissolved photoresist polymer to keep the developer bath at a fixed level of chemical activity.

Sensor for determining photoresist developer strength

A reflective beam of light is used to analyze the optical transmission properties of a developer fluid during puddle develop of photoresist polymer for detercting the process endpoint.

Process for determining photoresist develop time by optical transmission

A method and apparatus is provided for removing submicron sized particles from the surface of a silicon semiconductor wafer (38). Conventional cleaning methods are capable of only removing particles that are about 1 micron or larger in size. The present invention provides a way to increase the submicron particles in size so that they are removable by the known methods. The silicon semiconductor wafer (38) is cooled by a refrigeration unit (36) or by exposure to liquid nitrogen (74). The cooled wafer (38) is then exposed to a condensable material (42) which is allowed to condense on the surface of the wafer (38). The condensable material will surround any particles that are on the surface and cause them to grow in size due to the formation of frozen crystals. Without allowing the crystals to melt, the enlarged particles then are removed by any of the known methods.

Method and apparatus for easing surface particle removal by size increase

A transport mechanism (40) for transporting a semiconductor slice cassette between a clean carrier (10) and a process machine comprises a housing (41) having a forward portion (42) positioned in the people-occupied area of the clean room and a rear portion (46) positioned in the process machine area aerodynamically isolated from people. A moveable glider plate (50) is adapted to receive the carrier (10) and is initially positioned in an aperture provided in the upper surface of forward portion (42). A gearing mechanism (54) is provided which cooperates with glider plate (50) to move the semiconductor slice cassettes mounted on the base of carrier (10) between forward portion (42) and rear portion (46). The semiconductor slices are shielded from particulate contamination as the semiconductor cassette is transported on glider plate (50) between forward portion (42) and rear portion (46) and for evacuating any particulate contamination generated within transport mechanism (40) to create a negative pressure therein relative to the people-occupied area and the process machine area.

Semiconductor slice cassette transport unit

A portable carrier (10) for storage and transportation of semiconductor slice cassettes in a clean room environment which shields the semiconductor slices from VLF air in people occupied areas includes a base (12), a pair of spring-mounted cradles (14) mounted on base (12) for supporting the semiconductor slice cassette and a cover (16) for disposal on base (12) to provide a sealed volume. Carrier (10) also includes a latch (20) for removably coupling cover (16) onto base (12). Latch (20) includes a handle (22) at the terminal end thereof to facilitate handling and transporting of carrier (10) when cover (16) is locked in place on base (12). A latch tube (24) is mounted proximate the center of base (12) and cooperates with latch (20) to couple cover (16) onto base (12). A pair of particle filters (26) are mounted on base (12) and positioned beneath cradles (14) to equalize the pressure on the interior and exterior of carrier (10) and thus reduce the pressure drop across seal (18) to zero under normal conditions. A pair of guides (28) are positioned proximate the rear of base (12) to either side thereof and outside seal (18). Guides (28) are adapted to be disposed through apertures provided in cover (16) to facilitate placement of cover (16) onto base (12) and prevent misalignment thereof.

Semiconductor slice cassette carrier

Method and apparatus for cleaning the surface of a slice of semiconductor material through the use of a liquid spray, wherein the liquid spray is delivered at an angle to the exposed surface of a rotating semiconductor slice at a controlled pressure and velocity, and strikes the surface of the semiconductor slice substantially along a linear path coinciding with the diameter of the slice. The apparatus includes an upstanding pedestal having a slice-supporting surface on which the slice of semiconductor material to be cleaned is disposed. The pedestal is mounted within a housing which includes a motor for imparting rotation to the pedestal and a vacuum pump for inducing a suction in openings provided in the slice-supporting surface of the pedestal so as to retain the slice in place when rotary movement is imparted thereto. A spray nozzle for delivering a flat fan-shaped spray pattern is disposed within the housing, the spray nozzle being positioned above the level of the slice-supporting surface for dispensing a liquid spray onto the exposed surface of the slice positioned thereon. The housing is also provided with a transparent dome-shaped cover overlying the upstanding pedestal and the spray nozzle to define a cleaning chamber. The cover in its closed position completes an electric circuit operating the motor and the vacuum pump to impart rotation to the pedestal and to retain the semiconductor slice upon the surface of the pedestal by inducing suction in the openings provided therein. De-ionized water is delivered from the spray nozzle as a liquid spray to the surface of the semiconductor slice at a high pressure and velocity to produce a corona discharge for effecting a cleaning operation of the exposed surface of the semiconductor slice wherein particulate surface debris of a particle size smaller than the width of the theoretically determined dead space layer associated with the exposed slice surface is removed therefrom.

Growing community of inventors

Dallas, TX, United States of America

Edwin G Millis