LARGE-AREA LASER HEATING SYSTEM

The instant disclosure provides a large-area laser heating system including a laser module, a reaction module and a guiding module. The laser module includes a vertical-cavity surface-emitting laser for emitting a laser beam and a laser adjusting structure connected to the vertical-cavity surface-emitting laser. The incident angle of the laser beam emitted by the vertical-cavity surface-emitting laser is adjusted by the laser adjusting structure. The reaction module includes a sample holder for carrying a sample. The guiding module is connected between the laser module and the reaction module, and the laser beam emitted by the vertical-cavity surface-emitting laser passes through the guiding module and projects onto the surface of the sample.

BACKGROUND

1. Technical Field

The instant disclosure relates to a heating system, in particular, to a large-area laser heating system.

2. Description of Related Art

In the semiconductor industry, thin film deposition process is generally used for preparing oxide products and hence, during or after the thin film deposition process, the reaction chamber is filled with oxygen atmosphere. In addition, most of the deposition processes include the heating of the sample to high temperatures in order to form the oxide products.

However, in the existing art, the procedure of heating the sample to high temperatures under oxygen atmosphere has certain difficulties. Since most of the filament materials for performing heating undergo oxidation under an oxygen atmosphere while being heated, the heaters used under an oxygen atmosphere mostly employ infrared lamp or a heater made of platinum, silicon carbide, molybdenum disilicide or Inconel. However, the above heaters still have the disadvantages of high power consumption, short lifetime and difficulties related to maintenance. For example, platinum heaters have shorter lifetime and silicon carbide heaters require regular maintenance. Therefore, the conditions and parameters for performing thin film process must be changed and the stability of the product quality is decreased, or the experimental results are not accurate.

In addition, the heating source provided by the conventional resistance wire heater is radioactive and the impurities in the material of the equipment near to the heater may be released and pollute the products. Alternatively, the material deposited by the thin film deposition process can be released and become impurities in the reaction environment.

Along with the increase of the size of the products prepared by thin film deposition processes, how to effectively achieve the heating of the sample has become an object of study in the industry. Therefore, there is a need for providing a large-area heating system which can be used under oxygen atmosphere.

SUMMARY

An exemplary embodiment of the present disclosure provides large-area laser heating system comprising a laser module, a reaction module and a guiding module. The laser module comprises at least a vertical-cavity surface-emitting laser for emitting at least a laser beam, and a laser adjusting structure connected to the vertical-cavity surface-emitting laser. The incident angle of the laser beam emitted by the vertical-cavity surface-emitting laser is adjusted by the laser adjusting structure. The reaction module comprises a sample holder for holding a sample. The guiding module connects between the laser module and the reaction module, wherein the laser beam emitted by the vertical-cavity surface-emitting laser passes through the guiding module and projects onto a surface of the sample.

Preferably, the large-area laser heating system according to claim1, further comprising a cooling module connected to the laser module and the guiding module, wherein the cooling module provides cooling water to cool the laser module and the guiding module.

Preferably, the guiding module is a vertical chamber having a jacket structure for cooling water to pass by.

Preferably, the large-area heating system further comprises a temperature detecting device disposed beside the vertical-cavity surface-emitting laser for directly monitoring the temperature of the sample.

Preferably, the temperature detecting device is an infrared temperature detecting device.

Preferably, the guiding module comprises an optical component, and the laser beam passes through the optical component of the guiding module and focuses on the surface of the sample.

Preferably, the size of the sample carrying by the sample holder is larger than 2 inches.

According to another embodiment of the present disclosure, a large-area laser heating system comprising a laser module, a reaction module and a guiding module. The laser module comprises a plurality of vertical-cavity surface-emitting lasers for emitting a plurality of laser beams, and a laser adjusting structure connected to the plurality of vertical-cavity surface-emitting lasers. The incident angle of each laser beam emitted by the plurality of vertical-cavity surface-emitting lasers is adjusted by the laser adjusting structure. The reaction module comprises a sample holder for carrying a sample. The guiding module is connected between the laser module and the reaction module, in which the plurality of laser beams of the plurality of vertical-cavity surface-emitting lasers passes through the guiding module and is guided to a surface of the sample. An optical axis of each laser beam emitted by the plurality of vertical-cavity surface-emitting lasers slants relative to a central axis of the guiding module.

Preferably, an arrangement of the plurality vertical-cavity surface-emitting lasers of the laser module is arc-shaped.

To sum up, the advantages of the instant disclosure reside in that the large-area laser heating system comprising the structure designs, i.e., a laser module comprising a vertical-cavity surface-emitting laser and a laser adjusting structure, and a guiding module for guiding the laser beam emitted by the laser toward the surface of the sample, can achieve the heating of a large-area sample. Meanwhile, since the laser module used as a heater is disposed outside of the reaction module, the structure design of the instant disclosure can further prevent the influences caused by the reaction gases in the reaction chamber on the heater, thereby increasing the stability of the process and reducing the cost of the process and the maintenance of the system.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Please refer toFIG. 1toFIG. 3.FIG. 1is a three-dimensional schematic view of the large-area laser heating system of the embodiments of the instant disclosure,FIG. 2is a sectional view of the large-area laser heating system of the embodiments of the instant disclosure, andFIG. 3is a block diagram of the large-area laser heating system of the embodiments of the instant disclosure. The large-area laser heating system S provided by the embodiments of the instant disclosure comprises a laser module1, a reaction module2and a guiding module3. As shown inFIG. 1andFIG. 2, the guiding module3is connected between the laser module1and the reaction module2. Specifically, the guiding module3is a vertical cavity. The laser module1is disposed at the upper end of the guiding module3and the reaction module2is disposed at the lower end of the guiding module3. In addition, the reaction module2can be sleeved on a part of the guiding module3, i.e., a part of the reaction module2surrounds the lower part of the guiding module3.

For example, the laser module1comprises at least a vertical-cavity surface emitting laser (VSCEL)11. However, in the instant disclosure, the number of the vertical-cavity surface-emitting laser11comprised by the laser module1is not limited. In the embodiment shown inFIG. 1andFIG. 2, the laser module1comprises six vertical-cavity surface-emitting lasers11. In addition, sinceFIG. 2is a sectional view taken along the II-II line inFIG. 1,FIG. 2only shows half of the number of the vertical-cavity surface-emitting laser11(i.e., three vertical-cavity surface-emitting lasers11).

The vertical-cavity surface-emitting laser11emits a laser beam (not shown). The VCSEL is a laser diode based on semiconductors which emits a high energy light beam from the top surface thereof along a direction perpendicular to the top surface. Specifically, the main difference between the VCSEL and the conventional laser diode is the relative position between the resonance cavity and the epitaxial layer. In conventional diodes, the resonance cavity and the epitaxial layer are parallel to each other, and the reflective surface is formed by natural fracture and is perpendicular to the epitaxial layer and hence, the laser is emitted from the side surface and is referred to as an “Edge-emitting Laser”. In a vertical-cavity surface-emitting laser, the resonance cavity is perpendicular to the epitaxial layer, and the reflective surface consists of an epitaxial layer or surface dielectric thin film and hence, the laser is emitted from the front side. The vertical-cavity surface-emitting laser has the property of surface-emitting and the advantages of low power consumption and low thermal effect. Therefore, in the embodiments of the instant disclosure, the vertical-cavity surface-emitting laser11emits laser light from a surface light source.

In addition, the vertical-cavity surface-emitting laser11can be electrically connected to a laser controller (not shown), and the laser controller further comprises a thermometer and a proportional-integral-derivative (PID) temperature controller. The wavelength and energy of the laser beam emitted by the vertical-cavity surface-emitting laser11is not limited in the instant disclosure. For example, the wavelength of the laser beam can be 980 nanometers and the energy of the laser beam can be 120 W. The vertical-cavity surface-emitting laser11can heat the sample22to over 1200° C.

As shown inFIG. 1, the laser module1further comprises a laser adjusting structure12connected to the vertical-cavity surface-emitting laser11. The laser adjusting structure12is a moving platform which can move along X, Y, Z axes and rotate relative to an axis. Specifically, as shown inFIG. 1andFIG. 2, the laser adjusting structure12can surround a part of the vertical-cavity surface-emitting laser11or partially surround the vertical-cavity surface-emitting laser11and have at least a bearing surface121on which the vertical-cavity surface-emitting laser11is fixed. The laser adjusting structure12is used for adjusting the emitting angle of the laser beam emitted by the vertical-cavity surface-emitting laser11, i.e., adjusting the incident light entering the guiding module3. In other words, in the embodiments of the instant disclosure, the incident angle of the laser beam emitted by the vertical-cavity surface-emitting laser11is adjusted by the laser adjusting structure12.

The laser adjusting structure12is connected to a processor (such as a micro-processor) and an external controller for controlling the setting angle and direction of the vertical-cavity surface-emitting laser11relative to the guiding module3. Specifically, by adjusting the inclined degree of the bearing surface121of the laser adjusting structure12through the processor and the external controller, the incident angle of the laser beam emitted from the vertical-cavity surface-emitting laser11can be adjusted. Therefore, when the laser module1comprises a plurality of vertical-cavity surface-emitting lasers11, the optical axes of the plurality of laser beams emitted by the plurality of vertical-cavity surface-emitting lasers11respectively can slant relative to the central axis of the guiding module3. The central axis of the guiding module3is an axis passing through the center of the guiding module3and perpendicular to the horizontal axis.

When the laser module1of the large-area laser heating system S provided by the embodiments of the instant disclosure comprises a plurality of vertical-cavity surface-emitting lasers11, the relative position between each vertical-cavity surface-emitting laser11can be designed to achieve optimum heating efficiency. For example, as shown inFIG. 1andFIG. 2, the laser module1comprises six vertical-cavity surface-emitting lasers11, and the laser adjusting structure12comprises two bearing surfaces121. Each bearing surface121is used to fix three vertical-cavity surface-emitting lasers11, and the arrangement of the three vertical-cavity surface-emitting lasers11fixed on the bearing surface121is arc-shaped when observed from the position facing the bearing surface121. In other words, the light emitting surfaces of each vertical-cavity surface-emitting laser11fixed on the same bearing surface121are not parallel to each other. Therefore, the light condensing efficiency is improved and the heating uniformity is increased. Alternatively, by adjusting the incident angle of the laser beam, the range of the laser projected onto the sample22can be accurately controlled, thereby preventing the problem related to impurity releasing from the material of the equipment caused by oversized heating range.

Under the arrangement of the vertical-cavity surface-emitting lasers11relative to the bearing surfaces121mentioned above, the inclined degree of the bearing surface121can be adjusted through the process and the external controller electrically connected to the laser adjusting structure12. In other words, by adjusting the inclined degree of the bearing surfaces121relative to the horizontal surface, the incident angles of the laser beams emitted from the vertical-cavity surface-emitting lasers11fixed on the bearing surfaces121can be adjusted.

Next, please refer toFIG. 2. The reaction module2comprises a sample holder21for carrying the sample22. The reaction module2is a reaction chamber for conducting thin film deposition process. During the thin film deposition process of oxides, the reaction module2generally is filled with oxygen atmosphere. The sample holder21is disposed at the bottom of the reaction module2and carries the sample22. The type and size of the sample22is not limited in the instant disclosure. Preferably, since the instant disclosure employs vertical-cavity surface-emitting laser11having surface emitting property as the heating source, the size of the sample22can be larger than 2 inches.

The large-area laser heating system S further comprises a temperature detecting device23disposed between the plurality of vertical-cavity surface-emitting lasers11for directly monitoring the temperature of the sample22. In other words, the temperature detecting device23can be disposed beside the vertical-cavity surface-emitting laser11. In another embodiment (not shown), the temperature detecting device23can be disposed at a position near to the sample holder21in the reaction module2. In existing art, a thermometer using thermocouples is used to indirectly measure the temperature of the heater for achieving temperature monitoring. However, such a means is not accurate and cannot achieve real-time temperature monitoring. Therefore, in the large-area laser heating system S provided by the embodiments of the instant disclosure, the temperature detecting device23is directly disposed in the laser module1or the reaction module2and is an infrared temperature detecting device (such as a thermometer), or a pyrometer sensor. Therefore, the accuracy of the temperature monitoring can be increased and real-time monitoring can be achieved. In addition, according to the temperature detected by the temperature detecting device23, the laser module1of the large-area laser heating system S can be controlled based on the needs of the process or the experiments for controlling the speed of heating or cooling of the sample22.

As shown inFIG. 1andFIG. 2, the laser module1and the reaction module2are connected through the guiding module3. In other words, the guiding module3is connected between the laser module1and the reaction module2. The guiding module3is used for the laser beam emitted by the vertical-cavity surface-emitting laser11to pass through, thereby guiding the laser beam to the surface of the sample22. The design of the guiding module3can extend the light path of the laser beam, thereby increasing the uniformity of the laser beam projected onto the surface of the sample22. For example, the guiding module3is a vertical chamber comprising an optical component32, and the laser beam emitted by the vertical-cavity surface-emitting laser11passes through the optical component32and focuses on the surface of the sample22. In the embodiment shown inFIG. 2, the optical component32is a cylindrical quartz light guide.

During the use of the large-area laser heating system S provided by the embodiments of the instant disclosure, the laser beam emitted by the vertical-cavity surface-emitting laser11of the laser module1can produce maximum heating power after being focused by the guiding module3. However, since the laser provides divergent heating, the components of the laser module1and the guiding module3are irradiated by the laser and the temperatures thereof rises. Therefore, the large-area laser heating system S provided by the embodiments of the instant disclosure further comprises a cooling module4connected to the laser module1and the guiding module3for providing cooling water. The cooling water cools the laser module1and the guiding module3. For example, as shown inFIG. 2, the guiding module3has a jacket structure31for the cooling water to pass by. Therefore, the cooling module4can prevent the impurities in the components of the laser module1and the guiding module3from releasing and polluting the sample22.

In summary, the advantages of the instant disclosure reside in that the large-area laser heating system S provided by the embodiments of the instant disclosure which comprises the structure of “a laser module1comprising a vertical-cavity surface-emitting laser11and a laser adjusting structure12” and “a guiding module3for guiding the laser beam emitted by the vertical-cavity surface-emitting laser11to the surface of the sample22” can achieve heating on large-area samples. Meanwhile, since the laser module1used as the heater is disposed outside of the reaction module2, the large-area laser heating system S provided by the instant disclosure can prevent the reaction gases in the reaction module2from influencing the heater, thereby increasing the stability of the process and reducing the cost of the process and maintenance.

The above-mentioned descriptions represent merely the exemplary embodiment of the present disclosure, without any intention to limit the scope of the instant disclosure thereto. Various equivalent changes, alterations or modifications based on the claims of the instant disclosure are all consequently viewed as being embraced by the scope of the instant disclosure.