Screen Holdings Co., Ltd.

Hideaki Tanimura

Kazuhiko Fuse

Shinichi Kato

Hikaru Kawarazaki

Takayuki Aoyama

Masashi Furukawa

Akitsugu Ueda

Takahiro Yamada

Makoto Abe

Hiroshi Miyake

Shinji Miyawaki

Yasuaki Kondo

Kaoru Matsuo

A light diffusion plate is placed on an upper surface of an upper chamber window. A blasting process is applied to a lower surface of the light diffusion plate to provide the lower surface in the form of frosted glass. When the light diffusion plate is placed on the upper surface of the upper chamber window, the light diffusion plate and the upper chamber window do not closely adhere to each other. The frosted glass releases a mass of air entering between contact surfaces of the light diffusion plate and the upper chamber window to the outside even if the mass of air thermally expands during heat treatment. This restrains the occurrence of a phenomenon in which a thin layer of air is trapped between the light diffusion plate and the upper chamber window to prevent the sliding of the light diffusion plate resulting from the air layer.

Light irradiation type heat treatment apparatus

A semiconductor wafer held by a holding part in a chamber is irradiated and heated with halogen light emitted from a plurality of halogen lamps. A cylindrical louver and an annular light-shielding member, both made of opaque quartz, are provided between the halogen lamps and the semiconductor wafer. The outer diameter of the light-shielding member is smaller than the inner diameter of the louver. Light emitted from the halogen lamps and passing through a clearance between the inner wall surface of the louver and the outer circumference of the light-shielding member is applied to a peripheral portion of the semiconductor wafer where a temperature drop is likely to occur. On the other hand, light travelling toward an overheat region that has a higher temperature than the other region and appears in the surface of the semiconductor wafer when only a louver is installed is blocked off by the light-shielding member.

Light-irradiation heat treatment apparatus

A semiconductor wafer to be treated is heated at a first preheating temperature ranging from 100 to 200&#xb0; C. while a pressure in a chamber housing the semiconductor wafer is reduced to a pressure lower than an atmospheric pressure. After the semiconductor wafer is preheated to increase the temperature into a second preheating temperature ranging from 500 to 700&#xb0; C. while the pressure in the chamber is restored to a pressure higher than the reduced pressure, a flash lamp emits a flashlight to a surface of the semiconductor wafer. Heating the semiconductor wafer at the first preheating temperature that is a relatively low temperature enables, for example, the moisture absorbed on the surface of the semiconductor wafer in trace amounts to be desorbed from the surface, and also enables the flash heating treatment to be performed with oxygen derived from such absorption removed as much as possible.

Heat treatment method including low temperature degassing before flash lamp anneal and heat treatment apparatus thereof

A gallium nitride (GaN) substrate is injected with magnesium as a p-type dopant. The GaN substrate undergoes preheating through irradiation with light from halogen lamps in an atmosphere containing nitrogen and hydrogen, and further undergoes heating to a high temperature for a super-short time through irradiation with flashes of light from flash lamps. Heating the GaN substrate in the atmosphere containing nitrogen and hydrogen complements removed nitrogen, thus preventing nitrogen shortage. Such a heating process also enables heat treatment while supplying hydrogen to the GaN substrate. The heating process further enables crystal defects in the GaN substrate to be recovered. With these effects, the p-type dopant injected into the GaN substrate is activated with high efficiency.

Method for fabricating p-type gallium nitride semiconductor and method of heat treatment

Over a front surface of a silicon semiconductor wafer is deposited a high dielectric constant film with a silicon oxide film, serving as an interface layer, provided between the semiconductor wafer and the high dielectric constant film. After a chamber houses the semiconductor wafer, a chamber's pressure is reduced to be lower than atmospheric pressure. Subsequently, a gaseous mixture of ammonia and nitrogen gas is supplied into the chamber to return the pressure to ordinary pressure, and the front surface is irradiated with a flash light, thereby performing post deposition annealing (PDA) on the high dielectric constant film. Since the pressure is reduced once to be lower than atmospheric pressure and then returned to ordinary pressure, a chamber's oxygen concentration is lowered remarkably during the PDA. This restricts an increase in thickness of the silicon oxide film underlying the high dielectric constant film by oxygen taken in during the PDA.

Light-irradiation heat treatment method and heat treatment apparatus

Hydrogen annealing for heating a semiconductor wafer on which a thin film containing a dopant is deposited to an annealing temperature under an atmosphere containing hydrogen is performed. A native oxide film is inevitably formed between the thin film containing the dopant and the semiconductor wafer, however, by performing hydrogen annealing, the dopant atoms diffuse relatively easily in the native oxide film and accumulate at the interface between the front surface of the semiconductor wafer and the native oxide film. Subsequently, the semiconductor wafer is preheated to a preheating temperature under a nitrogen atmosphere, and then, flash heating treatment in which the front surface of the semiconductor wafer is heated to a peak temperature for less than one second is performed. The dopant atoms are diffused and activated in a shallow manner from the front surface of the semiconductor wafer, thus, the low-resistance and extremely shallow junction is obtained.

Heat treatment method for dopant introduction

A germanium semiconductor layer doped with a dopant such as boron becomes a p-type semiconductor. The semiconductor layer is preheated at a preheating temperature ranging from 200&#xb0; C. to 300&#xb0; C., and then heated at a treatment temperature ranging from 500&#xb0; C. to 900&#xb0; C., by extremely short-time irradiation of flash light. While oxygen is unavoidably mixed in germanium and becomes a thermal donor at 300&#xb0; C. to 500&#xb0; C., the semiconductor layer stays in a temperature range of 300&#xb0; C. to 500&#xb0; C. for a negligibly short period of time due to an extremely short irradiation time of 0.1 milliseconds to 100 milliseconds by the flash light. Therefore, the thermal donor can be prevented from being generated in the germanium semiconductor layer.

Heat treatment method for p-type semiconductor

A PSG film, which is a silicon dioxide thin film containing phosphorus as a dopant, is formed on the surface of a semiconductor wafer. The semiconductor wafer having the PSG film formed thereon is kept at a predetermined heating temperature by light radiation from halogen lamps in the atmosphere containing hydrogen for 1 second or longer, so that the dopant is diffused from the PSG film into the surface of the semiconductor wafer. In addition, the flashing light is radiated to the semiconductor wafer for the radiation time shorter than 1 second to heat the surface of the semiconductor wafer to the target temperature so as to activate the dopant. When the PSG film is heated in the atmosphere containing hydrogen, a diffusion coefficient of the dopant contained in the PSG film becomes high; therefore, the dopant can be efficiently diffused from the PSG film into the semiconductor wafer.

Dopant introduction method and thermal treatment method

A heat treatment apparatus is provided with two cool chambers, that is, a first cool chamber and a second cool chamber. A semiconductor wafer before treatment is alternately carried into the first cool chamber or the second cool chamber and then transported to a heat treatment part by a transport robot after a nitrogen purge is performed. The semiconductor wafer after being heat-treated in the heat treatment part is alternately transported to the first cool chamber or the second cool chamber to be cooled. A sufficient cooling time is secured for the independent semiconductor wafer, and a reduction in throughput as the whole heat treatment apparatus can be suppressed.

A metal film is deposited on a front surface of a semiconductor wafer of silicon. After the semiconductor wafer is received in a chamber, the pressure in the chamber is reduced to a pressure lower than atmospheric pressure. Thereafter, nitrogen gas is supplied into the chamber to return the pressure in the chamber to ordinary pressure, and the front surface of the semiconductor wafer is irradiated with a flash of light, so that a silicide that is a compound of the metal film and silicon is formed. The oxygen concentration in the chamber is significantly lowered during the formation of the silicide because the pressure in the chamber is reduced once to the pressure lower than atmospheric pressure and then returned to the ordinary pressure. This suppresses the increase in resistance of the silicide resulting from the entry of oxygen in the atmosphere in the chamber into defects near the interface between the metal film and a base material.

Light irradiation type heat treatment method and heat treatment apparatus

Light is applied for preheating from a halogen lamp to a lower surface of a semiconductor wafer supported on a susceptor within a chamber. Thereafter, flash light is applied for flash heating from a flash lamp to an upper surface of the semiconductor wafer. High-temperature treatment gas heated by a heater is supplied into the chamber to preheat a structure inside the chamber including a susceptor before heat treatment for an initial semiconductor wafer of a lot starts. By raising the temperature of the structure inside the chamber to a temperature substantially equivalent to a temperature of the structure during steady treatment, all semiconductor wafers constituting the lot are supportable on the susceptor maintained at a constant temperature without the necessity of dummy running. Accordingly, a temperature history is equalized for all the semiconductor wafers.

Method and apparatus for light-irradiation heat treatment

A thin film containing a dopant is deposited on a surface of a semiconductor wafer. The semiconductor wafer on which the thin film containing the dopant is deposited is rapidly heated to a first peak temperature by irradiation with light from halogen lamps, so that the dopant is diffused from the thin film into the surface of the semiconductor wafer. The thermal diffusion using the rapid heating achieves the introduction of the necessary and sufficient dopant into the semiconductor wafer without producing defects. The surface of the semiconductor wafer is heated to a second peak temperature by further irradiating the semiconductor wafer with flashes of light from flash lamps, so that the dopant is activated. The flash irradiation which is extremely short in irradiation time achieves a high activation rate without excessive diffusion of the dopant.

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Kyoto, Japan

Hideaki Tanimura