An object is to provide a method for manufacturing a semiconductor device, in which the number of photolithography steps can be reduced, the manufacturing process can be simplified, and manufacturing can be performed with high yield at low cost A method for manufacturing a semiconductor device includes the following steps: forming a semiconductor film; irradiating a laser beam by passing the laser beam through a photomask including a shield for shielding the laser beam; subliming a region which has been irradiated with the laser beam through a region in which the shield is not formed in the photomask in the semiconductor film; forming an island-shaped semiconductor film in such a way that a region which is not irradiated with the laser beam is not sublimed because it is a region in which the shield is formed in the photomask; forming a first electrode which is one of a source electrode and a drain electrode and a second electrode which is the other one of the source electrode and the drain electrode; forming a gate insulating film; and forming a gate electrode over the gate insulating film

Method for Manufacturing Semiconductor Device

The invention provides a method for depositing a metal film on a substrate, comprising generating a high density plasma in a chamber, sputtering metal particles from a target to the substrate, and applying a modulated radio frequency (RF) bias to the substrate during deposition. Another aspect of the invention provides an apparatus for depositing a metal film on a substrate comprising a high density plasma physical vapor deposition (HDP PVD) chamber and a controller to modulate a RF bias power applied to a substrate in the chamber.

Step coverage and overhang improvement by pedestal bias voltage modulation

An LED array circuit includes a number of series connected LED pairs, each pair including two parallel connected oppositely polarized LEDS. The array is coupled to a standard AC voltage source in series with an inductor L having Q>5 and a reactance which is equivalent to the resistance of a current limiting resistor. The use of an inductor in place of a resistor increases the efficiency of the array to approximately 80%. The efficiency of the array is increased even further by coupling a capacitor parallel to the array and by tuning the inductor and capacitor to the frequency of the AC voltage source. According to one embodiment of the invention, a somg;e retro-fittable unit is provided wherein an inductor, a capacitor, and an array of LEDs are contained in a housing having substantially the same size and shape as a standard incandescent bulb or the lens/filter used in a traffic signal display. According to another embodiment of the invention, a single module is provided with a plurality of LED arrays, with each LED array having its own capacitor coupled in parallel thereto, and its own series coupled switch. The module is coupled to and across the AC voltage source, with one node of the module coupled to the AC voltage source by an inductor.

AC powered light emitting diode array circuits for use in traffic signal displays

The present invention generally provides a method and apparatus for forming a doped layer on a substrate to improve uniformity of subsequent deposition thereover. Preferably, the layer is deposited by a sputtering process, such as physical vapor deposition (PVD) or Ionized Metal Plasma (IMP) PVD, using a doped target of conductive material. Preferably, the conductive material, such as copper, is alloyed with a dopant, such as phosphorus, boron, indium, tin, beryllium, or combinations thereof, to improve deposition uniformity of the doped layer over the substrate surface and to reduce oxidation of the conductive material. It is believed that the addition of a dopant, such as phosphorus, stabilizes the conductive material surface, such as a copper surface, and lessens the surface diffusivity of the conductive material. The overall surface diffusivity of copper is reduced such that the tendency to agglomerate or to become discontinuous is reduced, thereby allowing the deposition of a smoother conductive film and thereby reducing localized agglomeration of the conductive material. The smoother film is highly desirable for subsequent deposition processes. A conductive material, such as copper, can be deposited on the deposited doped layer by a variety of processes including PVD, chemical vapor deposition (CVD), electroplating, electroless deposition and other deposition processes.

Method and apparatus for forming a sputtered doped seed layer

An iPVD apparatus (20) is programmed to deposit material (10) into high aspect ratio submicron features (11) on semiconductor substrates (21) by cycling between deposition and etch modes within a vacuum chamber (30). The modes operate at different power and pressure parameters. Pressure of more than 50 mTorr, for example, is used for sputtering material from a target while pressure of less than a few mTorr, for example, is used to etch. Bias power on the substrate is an order of magnitude higher for etching, producing several hundred volt bias for etching, but only a few tens of volts for deposition. The alternating etching modes remove deposited material that overhangs edges of features on the substrate, removes some of the deposited material from the bottoms (15) of the features, and resputters the removed deposited material onto sidewalls (16) of the features. The substrate (21) is cooled during deposition and etching, and particularly during etching to substantially below 0°C. RF energy is coupled into the chamber (30) to form a high density plasma, with substantially higher RF power coupled during deposition than during etching. The substrate (21) is moved closer to the plasma source during etching than during deposition.

Ionized PVD with sequential deposition and etching

A thin film forming method and apparatus is provided, wherein a negative voltage is applied alternate­ly to a target (6) and a substrate (8) to perform film formation and reverse sputter alternately. Further, a coil (5) is mounted between the target and the substrate and a high frequency current (3) is made to flow there­through to generate plasma. A negative base voltage smaller in absolute value than that during sputter may be applied to the substrate to make a fraction of Ar ions to flow into the substrate while it is subjected to reverse sputter. Thus, a film whose step coverage is 0.3 or more is possible. It becomes also possible to hole stable discharge and reverse sputter at high vacuum region. The pressure of an Ar atmosphere may be lowered to 10⁻³ Torr or less. A film whose peak value of x-ray diffraction strength in (111) plane is 150 Xcps or more is possible. Also, a barrier layer with a layered structure of granular and columnar crystals or a mixed structure thereof and hence with an efficient barrier effect and a large specific resistance is possible.

Method of and apparatus for sputtering

Disclosed is a method and apparatus for automatically controlling arc welding, wherein pieces of optical information provided by at least two bands of different wavelengths of light radiated from a weld area being arc-welded under predetermined welding conditions are alternately picked up by an optical device to extract various weld factors representing the actual status of the weld area from these pieces of optical information, and the extracted weld factors representing the actual status of the weld area are compared with the desired values of the weld factors representing the desired status of the weld area to compute the error or errors of the welding conditions, so that the welding conditions can be corrected on the basis of the detected error or errors of the welding conditions, whereby the weld factors can be controlled to the desired values.

Method and apparatus for automatically controlling arc welding

A method for forming a thin film wherein plural targets of different materials are alternately sputtered througth the switching of the electric powers supplied thereto, the particles produced from the sputtering are ionized and thereafter deposited on a substrate. This method provides an alloy thin film, compound thin film or multi-layer thin film of any composition and enhances adhesion among the particles. A sputtering device for practicing this method is also disclosed.

Thin film forming method through sputtering and sputtering device

A thin film forming method and apparatus, wherein a negative voltage is applied alternately to a target and a substrate to perform film formation and reverse sputter alternately. Further, a coil is mounted between the target and the substrate and a high frequency current is made to flow therethrough to generate plasma. A negative base voltage smaller in absolute value than that during sputter may be applied to the substrate to make Ar ions flow into the substrate while it is subjected to reverse sputter. Thus, a film whose step coverage is 0.3 or more is possible. It becomes also possible to maintain a stable discharge and perform reverse sputter in a high vacuum region. The pressure of an Ar atmosphere may be lowered to 10 -3 Torr or less. An aluminum wiring film whose peak value of x-ray diffraction strength at a (111) plane is 150 Kcps or more is possible. Also, a barrier layer having a layered structure of granular and columnar crystals or a mixed structure thereof providing an efficient barrier effect and a large specific resistance is possible.

Method of and apparatus for sputtering, and integrated circuit device

In a welding apparatus having a plurality of electrodes and adapted for carrying out welding operation on a workpiece by alternately supplying currents to the individual electrodes through switching elements, an apparatus and method of controlling the currents supplied to the electrodes, comprising selecting the values of the currents supplied to the individual electrodes depending on the material of the workpiece, and carrying out the welding operation on the workpiece by alternately supplying the currents of the selected values to the individual electrodes respectively through the switching elements. The method is featured by the fact that the ratio between the individual currents is selected under the condition that the sum of the values of all the currents is maintained at a predetermined value. It is also featured by the fact that, depending on the welding condition, the values of the individual currents can be freely selected without the limitation of maintaining the sum of all the currents at the predetermined value. Therefore, the apparatus and method are applicable to welding of a variety of materials by selecting the values of the individual currents depending on whether the workpiece has a high or low melting point and also whether the workpiece has a high or low heat conductivity.

Masayasu Nihei

Papers

Method of and apparatus for sputtering

Method and apparatus for automatically controlling arc welding

Thin film forming method through sputtering and sputtering device

Method of and apparatus for sputtering, and integrated circuit device

Method of electrode current control in welding apparatus having a plurality of electrodes