Heat processing system

A heat processing system is disclosed. The heat processing system includes an enclosure, a heater, and a plurality of valves disposed on the enclosure. The heater is used to increase temperature within the enclosure. The plurality of valves have different sizes to uniformly and efficiently control the cooling within the enclosure.

BACKGROUND

The present disclosure generally relates to heat processing system, and more particularly, heat processing system to generate uniform heat within enclosure.

2. Description of the Related Art

In order to manufacture a desired semiconductor unit, various thermal processes including an oxidation process, a diffusion process, a CVD process, an annealing process or the like are carried out to a substrate. As a thermal processing unit for conducting the processes, a heat processing system is used wherein a large number of wafers are thermally processed at a time.

DETAILED DESCRIPTION

FIG. 1illustrates a heat processing system according to some embodiments of the instant disclosure. The heat processing system includes an enclosure, a plurality of valves14, a heater11, a process chamber13, a temperature sensor12, and a cap16. The enclosure includes a surrounding wall10. The surrounding wall10having an inlet17and a plurality of outlets18. The plurality of outlets18have different diameters from each other. In some embodiments, the plurality of outlets18are holes formed on the surrounding wall10. An outlet nearest to the inlet is a hole on the surrounding wall10that has a smallest diameter of the holes of the plurality of outlets18. An outlet farthest from the inlet is a hole on the surrounding wall10that has a largest diameter of the holes of the plurality of outlets18.

In some embodiments, the plurality of outlets18includes four holes, a first hole and a second hole of the four holes have a diameter of 10 mm. A third hole of the four holes have a diameter of 15 mm. A fourth hole of the four holes having a diameter of 20 mm.

In some embodiments, the plurality of outlets includes four holes, a first hole and a second hole of the four holes are configured to each exhaust about 25% of an air current within the surrounding wall10. A third hole of the four holes is configured to exhaust about 20% of the air current within the surrounding wall10. A fourth hole of the four holes is configured to exhaust about 30% of the air current within the surrounding wall10.

In some embodiments, the plurality of valve14are disposed on an outer surface of the surrounding wall10. Each of the plurality of valves14correspondingly coupled to the plurality of outlets18. In some embodiments, the plurality of valves are triggered when pressure of an air current from the inlet is at least 10 kpa. In some embodiments, the plurality of valves are butterfly valves. In some embodiments, the plurality of valves are normally closed valves. In some embodiments, a valve14nearest to the to the inlet17has a smallest size of the plurality of valves14and a valve14farthest from the inlet17has a largest size of the plurality of valves14.

The heater11is distributed over an inner surface of the surrounding wall10. In some embodiments, the plurality of outlets18are further formed by holes on the heater11aligning to the holes formed on the surrounding wall10. The process chamber13is disposed within the surrounding wall10. The heater11is disposed between the surrounding wall10and the walls of the processing chamber13to further provide a layer of protection for the substrates20from direct heat generated by the heater11. The temperature sensor12is disposed within the process chamber13. There may be five temperature sensors12disposed within the process chamber13. In some embodiments, the five temperature sensors12area equidistant from each other. That is, the distance between neighboring temperature sensors12are all the same. The cap16is configured to seal the process chamber13. Furthermore, the cap16is configured to protect the plurality of substrates20being processed from outside environment.

The plurality of substrates20are disposed on a holder15to keep the substrates20in place. In some embodiments, the substrate20includes silicon. Alternatively, the substrate20may include germanium, silicon germanium, gallium arsenide or other appropriate semiconductor materials. In some embodiments, the shape of the substrates20is circular or quadrilateral, such as a square or a rectangle. Also alternatively, the substrate20may include at least one of an epitaxial layer, a silicon layer, and a silicon dioxide layer.

In some embodiments, the heat processing system further includes a plurality of pipes disposed between the plurality of outlets18and the plurality of valves14to correspondingly couple the plurality of outlets18to the plurality of valves14.

FIG. 2illustrates a heat processing system according to some embodiments of the instant disclosure. The heat processing system includes a furnace1. The furnace includes an enclosure, a plurality of valves, a heater, a process chamber, a temperature sensor, and a cap. In some embodiments, the heat processing system further includes a cooling unit2coupled to the inlet of the surrounding wall. The cooling unit2have an inlet21and an outlet22. In some embodiments, the cooling unit2further includes a valve23disposed over the inlet21of the cooling unit2and an actuator coupled to the valve to control an opening of the valve23. The arrow D1shows a direction wherein air enters the cooling unit2. The arrow D2shows a direction wherein a cool gas from the cooling unit2is fed into the furnace1. Since the cooling gas from the cooling unit2is evenly distributed within the furnace1, the cooling time of the substrates being processed in the furnace1is reduced.

In some embodiments, the heat processing system further includes a power source3electrically coupled to the furnace1. The power source3is configured to supply power to the furnace1to operate. In some embodiments, the heat processing system further includes a pump4coupled to the furnace1and a selective catalyst reduction (SCR) unit5coupled to the pump4. In some embodiments, the pump4is used to extract unwanted exhaust from the furnace1. In some embodiments, the SCR unit5is used to convert the unwanted exhaust from the furnace1to disposable waste material such as water and harmless gas.

FIG. 3illustrates a flowchart of a heat processing method according to some embodiments of the instant disclosure. In some embodiments, a heat processing system includes a furnace. The furnace includes an enclosure having a surrounding wall, a plurality of valves, a heater, a process chamber, a temperature sensor, and a cap. The heat processing method for semiconductor fabrication includes heating a substrate disposed in a process chamber of a furnace (301) and performing a cooling operation to cool the process chamber (302).

The process chamber is disposed within the surrounding wall. The temperature sensor is disposed within the process chamber. In some embodiments, there may be five temperature sensors disposed within the process chamber. Furthermore, there may be a plurality of substrates disposed within the process chamber. The plurality of substrates are disposed on a holder to keep the substrates in place. In some embodiments, the substrate includes silicon. Alternatively, the substrate may include germanium, silicon germanium, gallium arsenide or other appropriate semiconductor materials. In some embodiments, the shape of the substrates is circular or quadrilateral, such as a square or a rectangle. Also alternatively, the substrate may include at least one of an epitaxial layer, a silicon layer, and a silicon dioxide layer. The cap is configured to seal the process chamber. The cap is configured to protect the plurality of substrates being processed from outside environment.

During the heating of the substrate, the substrate is heated using a heater distributed over an inner surface of a surrounding wall of the furnace. The heater is disposed between the surrounding wall of the enclosure and the walls of the processing chamber to further provide a layer of protection for the substrates from direct heat.

During a cooling operation, an air current is introduced around the process chamber through an inlet of the surrounding wall and exhausted through a plurality of valves disposed on an outer surface of the surrounding wall. The air current may be a cooling gas that has a temperature lower than the ambient air temperature within the furnace. In some embodiments, the temperature of the cooling gas may be the same as or lower than the target ambient temperature for the process chamber of the furnace.

Each of the plurality of valves is respectively coupled to one of a plurality of outlets arranged in the surrounding wall. The plurality of outlets have different diameter from each other. In some embodiments, the plurality of outlets includes four holes. a first hole and a second hole of the four holes have a diameter of 10 mm. A third hole of the four holes have a diameter of 15 mm. A fourth hole of the four holes having a diameter of 20 mm.

In some embodiments, the plurality of outlets includes four holes, a first hole and a second hole of the four holes are configured to each exhaust about 25% of an air current within the surrounding wall. A third hole of the four holes is configured to exhaust about 20% of the air current within the surrounding wall. A fourth hole of the four holes is configured to exhaust about 30% of the air current within the surrounding wall.

In some embodiments, each of the plurality of valves correspondingly coupled to the plurality of outlets. In some embodiments, the plurality of valves are triggered when pressure of an air current from the inlet is at least 10 kpa. In some embodiments, the plurality of valves are butterfly valves. In some embodiments, the plurality of valves are normally closed valves. In some embodiments, a valve nearest to the to the inlet has a smallest size of the plurality of valves and a valve farthest from the inlet has a largest size of the plurality of valves.

In some embodiments, the furnace further includes a plurality of pipes disposed between the plurality of outlets and the plurality of valves to correspondingly couple the plurality of outlets to the plurality of valves.

In some embodiments, the heat processing system further includes a cooling unit coupled to the inlet of the surrounding wall to provide the air current. The cooling unit have an inlet and an outlet. In some embodiments, the cooling unit further includes a valve disposed over the inlet of the cooling unit and an actuator coupled to the valve to control an opening of the valve. The air enters the inlet the cooling unit. A cool gas from the outlet of the cooling unit is fed into the furnace. Since the cooling gas from the cooling unit is evenly distributed within the furnace, the cooling time of the substrates being processed in the furnace is reduced.

In some embodiments, the heat processing system further includes a power source electrically coupled to the furnace. The power source is configured to supply power to the furnace to operate. In some embodiments, the heat processing system further includes a pump coupled to the furnace and a selective catalyst reduction (SCR) unit coupled to the pump. In some embodiments, the pump is used to extract unwanted exhaust from the furnace. In some embodiments, the SCR unit is used to convert the unwanted exhaust from the furnace to disposable waste material such as water and harmless gas.

Accordingly, one aspect of the instant disclosure provides a heat processing system that comprises an enclosure comprising a surrounding wall having an inlet and a plurality of outlets, the plurality of outlets having different diameter from each other; a plurality of valves disposed on an outer surface of the surrounding wall, each of the plurality of valves correspondingly coupled to the plurality of outlets; a heater distributed over an inner surface of the surrounding wall; a process chamber disposed within the surrounding wall; a temperature sensor disposed within the process chamber; and a cap configured to seal the process chamber.

In some embodiments, the system further comprises a cooling unit coupled to the inlet of the surrounding wall, the cooling unit having an inlet and an outlet.

In some embodiments, the cooling unit further comprising a valve disposed over the inlet of the cooling unit and an actuator coupled to the valve to control an opening of the valve.

In some embodiments, the plurality of outlets are holes formed on the surrounding wall, a hole nearest to the inlet having a smallest diameter of the holes and a hole farthest from the inlet having a largest diameter of the holes.

In some embodiments, the plurality of outlets includes four holes, a first hole and a second hole of the four holes having a diameter of 10 mm, a third hole of the four holes having a diameter of 15 mm, and a fourth hole of the four holes having a diameter of 20 mm.

In some embodiments, the plurality of outlets includes four holes, a first hole and a second hole of the four holes are configured to each exhaust about 25% of an air current within the surrounding wall, a third hole of the four holes is configured to exhaust about 20% of the air current within the surrounding wall, and a fourth hole of the four holes is configured to exhaust about 30% of the air current within the surrounding wall.

In some embodiments, the plurality of valves are triggered when pressure of an air current from the inlet is at least 10 kpa.

In some embodiments, the plurality of valves are butterfly valves.

In some embodiments, the plurality of valves are normally closed valves.

In some embodiments, the system further comprises a plurality of pipes disposed between the plurality of outlets and the plurality of valves to correspondingly couple the plurality of outlets to the plurality of valves.

In some embodiments, a valve of the plurality of valves nearest to the to the inlet has a smallest size of the plurality of valves and a valve of the plurality of valves farthest from the inlet has a largest size of the plurality of valves.

Accordingly, another aspect of the instant disclosure provides a heat processing method for semiconductor fabrication that comprises heating a substrate disposed in a process chamber of a furnace, in which the substrate is heated using a heater distributed over an inner surface of a surrounding wall of the furnace; and performing a cooling operation to cool the process chamber, in which an air current is introduced around the process chamber through an inlet of the surrounding wall and exhausted through a plurality of valves disposed on an outer surface of the surrounding wall, each of the plurality of valves being respectively coupled to one of a plurality of outlets arranged in the surrounding wall, the plurality of outlets having different diameter from each other.

In some embodiments, the air current for the cooling operation is supplied by a cooling unit coupled to the inlet of the surrounding wall, the cooling unit having an inlet and an outlet.

In some embodiments, the cooling unit further comprising a valve disposed over the inlet of the cooling unit and an actuator coupled to the valve to control an opening of the valve.

In some embodiments, the plurality of outlets are holes formed on the surrounding wall, a hole nearest to the inlet having a smallest diameter of the holes and a hole farthest from the inlet having a largest diameter of the holes.

In some embodiments, the plurality of outlets includes four holes, a first hole and a second hole of the four holes having a diameter of 10 mm, a third hole of the four holes having a diameter of 15 mm, and a fourth hole of the four holes having a diameter of 20 mm.

In some embodiments, the plurality of outlets includes four holes, a first hole and a second hole of the four holes each exhaust 25% of the air current, a third hole of the four holes exhaust 20% of the air current, and a fourth hole of the four holes exhaust 30% of the air current.

In some embodiments, the method further comprises triggering the plurality of valves when pressure of an air current from the inlet is at least 10 kpa and the plurality of valves are normally closed valves.

In some embodiments, the plurality of valves are butterfly valves.

In some embodiments, a valve of the plurality of valves nearest to the to the inlet has a smallest size of the plurality of valves and a valve of the plurality of valves farthest from the inlet has a largest size of the plurality of valves.