Methods for processing an amorphous silicon thin film sample into a polycrystalline silicon thin film are disclosed. In one preferred arrangement, a method includes the steps of generating a sequence of excimer laser pulses, controllably modulating each excimer laser pulse in the sequence to a predetermined fluence, homoginizing each modulated laser pulse in the sequence in a predetermined plane, masking portions of each homoginized fluence controlled laser pulse in the sequence with a two dimensional pattern of slits to generate a sequence of fluence controlled pulses of line patterned beamlets, each slit in the pattern of slits being sufficiently narrow to prevent inducement of significant nucleation in region of a silicon thin film sample irradiated by a beamlet corresponding to the slit, irradiating an amorphous silicon thin film sample with the sequence of fluence controlled slit patterned beamlets to effect melting of portions thereof corresponding to each fluence controlled patterned beamlet pulse in the sequence of pulses of patterned beamlets, and controllably sequentially translating a relative position of the sample with respect to each of the fluence controlled pulse of slit patterned beamlets to thereby process the amorphous silicon thin film sample into a single or polycrystalline silicon thin film.

Methods for producing uniform large-grained and grain boundary location manipulated polycrystalline thin film semiconductors using sequential lateral solidification

Systems and methods for reducing a surface roughness of a polycrystalline or single crystal thin film produced by the sequential lateral solidification process are disclosed. In one arrangement, the system includes an excimer laser (110) for generating a plurality of excimer laser pulses of a predetermined fluence, an energy density modulator (120) for controllably modulating the fluence of the excimer laser pulses such that the fluence is below that which is required to completely melt the thin film, a beam homoginizer (144) for homoginizing modulated laser pulses in a predetermined plane, a sample stage (170) for receiving homoginized laser pulses to effect melting of portions of the polycrystalline or single crystal thin film corresponding to the laser pulses, translating means for controllably translating a relative position of the sample stage (170) with respect to the laser pulses, and a computer (110) for coordinating the excimer pulse generation and fluence modulation with the relative positions of the sample stage (170) to thereby process the polycrystalline or single crystal thin film by sequential translation of the sample stage (170) relative to the laser pulses.

Surface planarization of thin silicon films during and after processing by the sequential lateral solidification method

A method and apparatus for processing a thin metal layer on a substrate to control the grain size, grain shape, and grain boundary location and orientation in the metal layer by irradiating the metal layer with a first excimer laser pulse having an intensity pattern defined by a mask to have shadow regions and beamlets. Each region of the metal layer overlapped by a beamlet is melted throughout its entire thickness, and each region of the metal layer overlapped by a shadow region remains at least partially unmelted. Each at least partially unmelted region adjoins adjacent melted regions. After irradiation by the first excimer laser pulse, the melted regions of the metal layer are permitted to resolidify. During resolidification, the at least partially unmelted regions seed growth of grains in adjoining melted regions to produce larger grains. After completion of resolidification of the melted regions following irradiation by the first excimer laser pulse, the metal layer is irradiated by a second excimer laser pulse having a shifted intensity pattern so that the shadow regions overlap regions of the metal layer having fewer and larger grains. Each region of the metal layer overlapped by one of the shifted beamlets is melted throughout its entire thickness, while each region of the metal layer overlapped by one of the shifted shadow regions remains at least partially unmelted. During resolidification of the melted regions after irradiation by the second radiation beam pulse, the larger grains in the at least partially unmelted regions seed growth of even larger grains in adjoining melted regions. The irradiation, resolidification and re-irradiation of the metal layer may be repeated, as needed, until a desired grain structure is obtained in the metal layer.

Method and apparatus for processing thin metal layers

High throughput systems and processes for recrystallizing thin film semiconductors that have been deposited at low temperatures on a substrate are provided. A thin film semiconductor workpiece is irradiated with a laser beam to melt and recrystallize target areas of the surface exposed to the laser beam. The laser beam is shaped into one or more beamlets using patterning masks. The mask patterns have suitable dimensions and orientations to pattern the laser beam radiation so that the areas targeted by the beamlets have dimensions and orientations that are conducive to semiconductor recrystallization. The workpiece is mechanically translated along linear paths relative to the laser beam to process the entire surface of the work piece at high speeds. Position sensitive triggering of a laser can be used generate laser beam pulses to melt and recrystallize semiconductor material at precise locations on the surface of the workpiece while it is translated on a motorized stage.

Single-shot semiconductor processing system and method having various irradiation patterns

A technique of spreading current flowing in a semiconductor device comprising an electrode, a drift region adjacent to the electrode, a junction termination extension implant region in the drift region, and a current spreader adjacent to the junction termination extension implant region and the electrode. The current spreader is adapted to reduce current densities and electrostatic fields (preferably simultaneously) in an area connecting the electrode with the drift region. Moreover, the current spreader is adapted to spread current flowing from the electrode into the drift region. The semiconductor device further comprises an ohmic metal contact connected to the electrode and an implant pocket in the drift region, wherein the implant pocket is adapted for terminating electrostatic field lines in the semiconductor device. Preferably, the current spreader comprises an ohmic metal and the electrode comprises any of an anode and a cathode.

Interacting current spreader and junction extender to increase the voltage blocked in the off state of a high power semiconductor device

A method of fabricating high-voltage diode device on a silicon substrate which includes a first region and a second region is provided. The first and second regions having a first contact and a second contact area respectively. First, a first protective layer is formed on the first and second contact areas. A second protective layer is formed on the first protective layer and a portion of the first region adjacent to the first contact area. Next. Halogen ions are implanted into the first and second regions by using the second protective layer as a mask. The second protective layer is removed to expose unimplanted portion of the first region. Then, the first and second regions are oxidized to form a field oxide layer by using the first protective layer as a mask, wherein the unimplanted portion of the first region has a relatively lower oxidation rate and thereby a stepped part of the field oxide layer is formed over the first region. After removing the first protective layer, a first electrode plate is formed on the first contact area and the stepped part of the field oxide layer. A dielectric layer is formed overlying the first electrode plate and the field oxide layer. Finally, a second electrode plate is formed on the second contact area and the dielectric layer, completing the fabrication of high-voltage diode device.

Sheng-Hsing Yang

Papers

Method of fabricating junction termination extension structure for high-voltage diode devices