There are disposed two homogenizers for controlling an irradiation energy density in the longitudinal direction of a laser light transformed into a linear one which is inputtted into the surface to be irradiated. Also, there is disposed one homogenizer for controlling an irradiation energy density in a width direction of the linear laser light. According to this, the uniformity of laser annealing can be improved by the minimum number of homogenizers.

Laser irradiation apparatus

The present invention generally describes apparatuses and methods used to perform an annealing process on desired regions of a substrate. In one embodiment, pulses of electromagnetic energy are delivered to a substrate using a flash lamp or laser apparatus. The pulses may be from about 1 nsec to about 10 msec long, and each pulse has less energy than that required to melt the substrate material. The interval between pulses is generally long enough to allow the energy imparted by each pulse to dissipate completely. Thus, each pulse completes a micro-anneal cycle. The pulses may be delivered to the entire substrate at once, or to portions of the substrate at a time. Further embodiments provide an apparatus for powering a radiation assembly, and apparatuses for detecting the effect of pulses on a substrate.

Pulse train annealing method and apparatus

The illumination energy of an excimer laser is measured and adjusted to always effect illumination at constant energy. A laser beam output from an optics is reflected by a mirror, and applied to a sample. A beam profiler is disposed behind the mirror to measure the energy of an illumination laser beam. An energy attenuating device disposed between another mirror and the optics is operated based on the measurement value so that the energy of the laser beam applied to the sample is kept constant.

Laser illumination system

A laser processing process which comprises laser annealing a silicon film 2 μm or less in thickness by irradiating a laser beam 400 nm or less in wavelength and being operated in pulsed mode with a pulse width of 50 nsec or more, and preferably, 100 nsec or more. A laser processing apparatus which comprises a laser generation device and a stage for mounting thereon a sample provided separately from said device, to thereby prevent transfer of vibration attributed to the movement of the stage to the laser generation device and the optical system. A stable laser beam can be obtained to thereby improve productivity.

Laser processing apparatus and laser processing process

On the occasion of the aligning process to transfer a predetermined pattern to a semiconductor wafer by irradiating a photoresist on the semiconductor wafer with an aligning laser beam of the modified lighting via a photomask MK, the photomask MK allocating, to provide periodicity, the main apertures to transfer the predetermined pattern as the apertures formed by removing a part of the half-tone film on the mask substrate and the auxiliary apertures not resolved on the semiconductor wafer as the apertures formed by removing a part of the half-tone film is used to improve the resolution of the pattern

Fabrication method of semiconductor integrated circuit device

PURPOSE:To simplify a photomask manufacturing process and increase the accuracy of the photomask by exposing a radiation sensitive org. resist film, to electron beams, which is opaque to ultraviolet rays or far ultraviolet rays. CONSTITUTION:Radiation sensitive org. resist film 3A which is opaque to ultraviolet rays or far ultraviolet rays is directly formed on substrate 1, and a desired pattern is formed in film 3A by exposure to electron beams, development and post- baking. Using the residual portion of film 3A as a light shielding portion, pattern printing is carried out with ultraviolet rays or far ultraviolet rays. Thus, the formation of a light shielding film, the etching of the film and the removal of the residual resist film are made unnecessary as compared to a conventional method, resulting in a simplified process.

Manufacture of photomask

PURPOSE:To manufacture a thin film with superior characteristics by irradiating a thin film on a substrate with energy beams to singlecrystallize it after covering the film surface with a protective film to prevent impurities from mixing into the film. CONSTITUTION:Polycrystalline Si thin film 3 is formed on the surface of amorphous heat oxidized SiO2 film 2 on Si substrate 1 by a chemical vapor deposition method, and by irradiating film 3 with energy beams 4, transient radiation annealing is carried out to single-crystallize film 3. In this thin film manufacturing method the annealing is carried out after covering the surface of film 3 with protective film 5 of silicon nitride Si3N4 or the like which can be formed at a relatively low temp. and has a m.p. higher than that of film 3. In this case, film 5 is not melted to prevent impurities from mixing into film 5. Thus, thin film 3 with superior characteristics is manufactured without requiring an airtight annealing apparatus or gas substitution.

Manufacture of thin film

PURPOSE:To detect an extent of the thermal treatment with wide operational region and large signal variation band by detecting acoustic wave generated along with beam radiation by an acoustic wave detection mechanism adhered to a part of a specimen. CONSTITUTION:A transducer 13 is pressed and adhered to a back of a wafer 3 by a jig and the surface of the wafer 3 is irradiated by a laser beam 1. The intensity of an acoustic wave signal detected by the transducer 13 is proportional to the power density of the laser beam but increases rapidly after the surface of the Si of the wafer 3 starts melting. After the molten state is reached, the intensity of the acoustic wave signal again becomes proportional to the power density of the laser beam. With this constitution, the extent of the thermal treatment can be detected by the acoustic wave.

Monitoring device for beam annealing

PURPOSE:To obtain the position of the center of gravity of vertical distribution and the surface density of charge trap center from the variation of the current-voltage characteristics, by producing the electron and positive hole pairs through the irradiation of electron rays on the surface of insulation film of MOS construction and measuring the current-voltage characteristics through the metal electrode applied with positive and negative DC voltage. CONSTITUTION:Electron beam 2 is radiated on the surface of the oxide film 1b through the gate metal electrode 1c of MOS diode 1 to produce the electrons and positive holes, and the current- voltage characteristics are measured with the voltmeter 4 and the ammeter 5 by applying the gate voltage of positive and negative polarity to the metal electrode 1c with the DC power supply 3. After electrons or positive holes are injected in the oxide film 1b with avalanche injection and they are trapped at the trap, the current-voltage characteristics are similarly measured. With known relation of equation from the amount of variation of this characteristic, the surface density of the charge trap center in the insulation film and the spatial distribution toward surface vertical direction for the center of gravity are obtained. Thus, the measurement of trap which is a cause to the instability of MOST can simply be measured.

Characteristic measuring method for charge trap center in insulator

PURPOSE:To reduce the thermal stress of the surface of a workpiece and prevent it from cracking, by setting the radial intensity of the central part of a light spot in accordance with a Gauss distribution and setting that of its peripheral part in accordance with another distribution of slower intensity gradient than the Gauss distribution. CONSTITUTION:If a light spot of intensity according to a simple Gauss distribution is irradiated, the temperature of the surface of a semiconductor shows a similar distribution. In that case, a region of 500 deg.C or more is limited within a radius of about 20mum when if the temperature of the center of the surface is 1,000 deg.C, so that high thermal stress is locally caused by the temperature difference between the central and the peripheral parts. To reduce such high thermal stress, a laser spot with an intensity distribution having a flat peripheral section or a peripheral section of slow gradient is used and the region of 500 deg.C or more is extended to a radius of about 40mum. Althrough the region of 500 deg.C or more can be extended by increasing the radius of a beam of simple Gauss distribution, it is hard to selectively anneal a minute zone and more energy is needed. The intensity distribution can be also changed by conducting a some of laser light 1 to points 7, 8 adjacent to an incident point 6, by way of mirrors 2-4.

Ootori Kouichirou

Papers

Manufacture of photomask

Manufacture of thin film

Monitoring device for beam annealing

Characteristic measuring method for charge trap center in insulator

Method of heat treatment by light