JP2008053401A - Lamp heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform heating capable of controlling dependency of lay out of temperatures at the time of rapid heating of a substrate, on which an element was formed on a front face. <P>SOLUTION: The lamp heating device 1 for heating a wafer S, as an heating object, in which a predetermined element is formed on the front face side, includes heating lamps 11, 12 arranged on both front and rear sides of the wafer S, and a lamp shield 20 which is arranged at the front face side of the wafer S in a state of surrounding the front face and side face of the wafer S. Through this lamp shield 20, radiant heat is effectively transmitted to the front face of the wafer S while light is absorbed from the heating lamp 11 arranged on the front face side of the wafer S. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lamp heating apparatus that performs rapid heating by irradiating light from a heating lamp onto a substrate on which a predetermined element is formed.

  RTP (Rapid Thermal Process) technology is widely used in LSI manufacturing, such as shallow junction formation and salicide formation. For RTP, lamp heating is mainly used. Lamp heating is performed by the wafer absorbing light from the lamp.

  FIG. 2 is a schematic cross-sectional view illustrating a conventional lamp heating device. The wafer S is transported into the chamber 10 in which the quartz plate 22 is stretched up and down, and after the opening of the chamber 10 is closed, the wafer S is heated by the heating lamps 11 and 12 at the upper and lower portions of the chamber. ing. Lamp light (infrared light) emitted from the heating lamps 11 and 12 passes through the quartz plate 22. A reflector 21 is attached behind the heating lamps 11 and 12 so that the wafer S can be efficiently irradiated with the lamp light. A pyrometer 23 for temperature measurement is attached to the lower part of the wafer S, and is usually heat-treated by closed loop control.

  As a conventional lamp heating device, in order to improve the uniformity of the light irradiation heat treatment temperature within the wafer surface, separate processing chambers are provided on the front surface side and the back surface side of the wafer, and a light source is provided only in the processing chamber on the back surface side of the wafer. There is a configuration to provide. Patent Document 1 discloses a configuration in which soaking plates are provided on the upper surface side and the lower surface side of a wafer housed in a processing container from the viewpoint of making the surface temperature of the wafer uniform.

JP-A-10-321547

  As described above, the lamp heating is performed by the wafer absorbing light from the lamp, and is an effective technique for high-speed heating and cooling. However, there are the following problems. That is, there are various pattern layouts on the wafer surface, each having a different film structure and impurity concentration. Therefore, a phenomenon occurs in which the amount of light absorption (processing temperature) is locally different. That is, layout dependency of temperature occurs.

  An example of a problem when the temperature dependence of layout occurs is given as an example. When lamp heating is used for annealing of Ni salicide formation, the Ni salicide sometimes grows abnormally in a state where the temperature is locally increased in a certain pattern due to different heating temperatures depending on the pattern. In recent years, with the miniaturization of devices, the diffusion layer has also become thinner, and abnormal growth of Ni salicide can cause Junction Leak.

  Further, as shown in Patent Document 1, a method of placing SiC LINER (heat equalizing plates) on the upper and lower sides of a wafer has been proposed, but it cannot prevent wraparound to the wafer surface side. In order to solve such problems of lamp heating, methods using heat convection and heat radiation by heater heating are also considered, but these heating methods still have a problem that high-temperature temperature rise is difficult.

  The present invention has been made to solve such problems. That is, the present invention provides a lamp heating apparatus for heating a substrate on which a predetermined element is formed on the front surface side, a heating lamp disposed on both the front surface side and the back surface side of the substrate, and a front surface side of the substrate. And a shield member that is disposed so as to surround the surface and side surfaces of the substrate.

  In the present invention, the light from the heating lamp disposed on the surface side of the substrate on which the predetermined element is formed is absorbed by the shield member, and the light from the heating lamp is directly applied to the surface side of the substrate. Without radiant heat from the shield member. On the other hand, the light from the heating lamp disposed on the back side can be directly applied to the back side of the substrate. As a result, heating can be rapidly performed from the back surface side of the substrate while achieving uniform heating temperature on the front surface side of the substrate on which the predetermined element is formed.

  Here, the lamp heating device of the present invention includes a chamber for storing the heating lamp and a reflector provided on the inner wall of the chamber, and the heating lamp in which the shield member is disposed on the surface side of the substrate. The light emitted from the substrate is arranged so as to surround the substrate so that it does not reach the surface of the substrate directly or after being reflected by a reflector.

  As a result, the light emitted from the heating lamp arranged on the surface side of the substrate is shielded by the shield member from both the light directed directly to the surface of the substrate and the light reflected by the reflecting plate and directed to the surface of the substrate. It is possible to eliminate a factor that makes the heating temperature on the surface side of the substrate non-uniform.

  In order to realize the configuration of the shield member, in the present invention, the shield member includes a surface-side shield portion that covers the surface side of the substrate and a side-surface shield portion that covers the side surface side of the substrate. It arrange | positions so that more than the back surface side edge part of the side surface of a board | substrate may be covered. As a result, it is possible to prevent light from the heating lamp arranged on the surface side of the substrate from entering from the side surface side.

  Further, the shield member is made of a material (for example, SiC) that absorbs light from a heating lamp arranged on the surface side of the substrate and transmits radiant heat to the surface of the substrate, and is thus arranged on the surface side of the substrate. While absorbing light from the heating lamp, radiant heat can be efficiently transmitted to the surface of the substrate.

  Therefore, the present invention has the following effects. That is, it becomes possible to suppress the layout dependence of the processing temperature due to the difference in the amount of light absorption depending on the film structure and pattern of the wafer that occurs during lamp heating. For example, when lamp heating is used for annealing for Ni salicide formation, the heating temperature does not differ depending on the pattern, so that it is possible to prevent Ni silicide from growing abnormally due to a local rise in temperature in a certain pattern. As a result, a highly reliable semiconductor device can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the configuration of the embodiment described below is merely an example, and is not intended to limit the present invention to the configuration of the embodiment.

  FIG. 1 is a schematic cross-sectional view showing a configuration of a lamp heating apparatus according to the present embodiment. That is, the lamp heating apparatus 1 of the present embodiment is arranged on the heating lamps 11 and 12 arranged on both the front surface side and the back surface side of the wafer (substrate) S to be heated, and on the front surface side of the wafer S, A lamp shield 20 disposed in a state surrounding the surface and side surfaces of the wafer S is provided as a main component. Here, the surface of the wafer S refers to a surface on which main elements are formed.

  The entire lamp heating apparatus 1 includes a chamber 10 in which heating lamps 11 and 12 and a wafer S to be heated are disposed, a reflector 21 attached to the inner wall of the chamber 10, heating lamps 11 and 12 and a wafer. And a quartz plate 22 disposed between S and S and a temperature-measuring porometer 23.

  The chamber 10 has a box shape or a cylindrical shape, and is made of metal such as aluminum or glass such as quartz. The chamber 10 is provided with a wafer introduction door 10a that can be opened and closed. By opening and closing the wafer introduction door 10a, the wafer S is carried into and out of the chamber 10.

  A susceptor 24 is mounted on the lower quartz plate 22 in the chamber 10, and a wafer S to be heated is placed on the susceptor 24. The upper and lower quartz plates 22 partition the space for heating the wafer S, and can sufficiently transmit the light emitted from the heating lamps 11 and 12.

  Further, since the inner surface of the chamber 10 around the heating lamps 11 and 12 is covered with the reflection plate 21, the light emitted radially from the heating lamps 11 and 12 is reflected by the reflection plate 21 to be heated. Can be led to the wafer S.

  In this embodiment, the heating lamp is not disposed on the side surface of the chamber 10, so it does not have to be a member that transmits lamp light such as quartz, and can be a metal such as water-cooled aluminum. . That is, the quartz plate 21 is required only on the upper and lower surfaces of the chamber 10.

  A pyrometer 23 for temperature measurement is installed in a portion of the chamber 10 that corresponds to the back side of the wafer S. In addition to the pyrometer 23, the temperature may be measured by a thermocouple that contacts the wafer S.

  The wafer S is inserted into the quartz chamber 10 from a wafer introduction door 10a provided in the chamber 10 shown on the left side of the drawing. The inserted wafer S is supported in the chamber 10 by a susceptor 24 made of quartz. The susceptor 24 is made of quartz in order to transmit the lamp light. Further, since the temperature uniformity is affected, it is necessary to reduce the contact area between the susceptor 24 and the wafer S as much as possible, and the wafer is supported by three or more point contacts.

  A cylindrical lamp shield 20 is disposed on the surface side of the wafer S placed in the chamber 10. The lamp shield 20 is made of, for example, SiC (silicon carbide) or C (carbon). Similarly to the wafer S, the lamp shield 20 is supported by a base 25 such as quartz. When the wafer S is transferred, the lamp shield 20 moves upward or the susceptor 24 moves downward so that the lamp shield 20 and the transfer system do not interfere with each other. Further, after the transfer, the wafer S enters the lamp shield 20.

  FIG. 2 is a schematic perspective view illustrating the configuration of the lamp shield. The lamp shield 20 includes a surface side shield portion 20a for covering the front surface side of the wafer S and a side surface shield portion 20b for covering the side surface side of the wafer S. The lamp shield 20 is surrounded by the surface from the surface of the wafer S to the side surface. It can be made cylindrical.

  The lamp shield 20 covers from the front surface of the wafer S to more than the rear surface side edge of the side surface, and the light from the heating lamp 11 disposed on the front surface side of the wafer S is reflected directly or reflected to the side surface side. It is possible to protect the wafer S from reaching the surface of the wafer S.

  The base 25 that supports the lamp shield 20 is a substantially L-shaped base in cross-section that supports the lower end of the side shield part 20b, and is provided along the circumference of the side shield part 20b. An opening is provided in the part. The wafer S can be taken in and out from the opening.

  After the wafer S enters the chamber 10 in a state surrounded by the lamp shield 20, the wafer introduction door 10a of the chamber 10 is closed. The wafer introduction door 10a is made of metal in order to improve the airtightness of the atmosphere in the chamber 10. However, cooling such as water cooling is performed to prevent metal contamination.

  In order to heat the wafer S with such a lamp heating apparatus 1, first, the wafer introduction door 10 a is opened, the wafer S is loaded into the chamber 10, and placed on the susceptor 24. At this time, the lamp shield 20 is prevented from interfering with the transport system. For example, the wafer S is loaded with the lamp shield 20 raised or the susceptor 24 lowered. Further, the wafer S is inserted from the opening of the base 25 of the lamp shield 20. After the wafer S is placed on the susceptor 24, the lamp shield 20 is disposed so as to surround the front surface side and the side surface side of the wafer S.

  Next, the wafer introduction door 10a is closed, the process gas is sent into the chamber 10 from the process gas introduction port, the atmosphere in the chamber 10 is replaced, and then the heating lamps 11 and 12 are energized to start lamp heating. To do.

  In this lamp heating, the light emitted from the heating lamp 12 is directly applied to the back side of the wafer S. Therefore, the back side of the wafer S absorbs the lamp light and is heated at a high speed. At this time, since there is no (or very few) element pattern on the back surface of the wafer S, there is no layout dependency that the temperature heating differs locally due to the influence of the pattern, and the in-plane of the wafer S is made uniform. Can be heated.

  On the other hand, since the surface side of the wafer S on which the element pattern is formed is covered with the lamp shield 20, the light emitted from the heating lamp 11 on the surface side is not directly irradiated. Further, since the wafer S is in the cylindrical lamp shield 20, the lamp light reflected by the reflecting plate 21 in the chamber 11 does not wrap around from the side surface side of the wafer S and reach the surface of the wafer S.

  By the way, the lamp shield 20 itself is made of, for example, SiC, so that the reflectance of the lamp light is low. The heating of the front surface side of the wafer S is performed only by radiant heat from the SiC lamp shield 20 which has become high temperature. Accordingly, the surface of the wafer S is not heated by the absorption of the lamp light, and is heated only by the radiant heat from the lamp shield 20, so that the surface of the wafer S is also heated regardless of the pattern layout.

  The entire temperature of the wafer S is sequentially detected by a temperature monitor such as a pyrometer 23 or a thermocouple, and the heat treatment is performed by controlling the power of the heating lamps 11 and 12 by closed loop control.

  Here, in order to reliably prevent the lamp light from being reflected around the surface of the wafer S by the lamp shield 20, it is desirable to make the gap between the lamp shield 20 and the surface of the wafer S as small as possible. Further, the side shield part 20 a of the lamp shield 20 covers the rear side edge part or more of the side face of the wafer S. Thereby, the wraparound of the lamp light can be further prevented.

  After irradiating lamp light from the heating lamps 11 and 12 for a predetermined time, the energization of the heating lamps 11 and 12 is stopped, the wafer introduction door 10a is opened, and the wafer S is taken out from the chamber 10.

  As described above, the lamp heating apparatus 1 according to the present embodiment can rapidly heat the wafer S without layout dependency. For example, the wafer S can be uniformly heated to about 1100 ° C. by heating for several seconds. Moreover, since it heats from the front and back of the wafer S, it heats efficiently compared with the heating of only one side. Furthermore, since the back surface of the wafer S is directly irradiated with the lamp light and the heating is performed by the absorption of the lamp light, the temperature rise does not become slower than the conventional double-sided lamp heating.

It is a schematic cross section explaining the lamp heating device according to the present embodiment. It is a model perspective view explaining a lamp shield. It is a schematic cross section explaining a conventional example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Lamp heating apparatus, 10 ... Chamber, 11 ... Heating lamp, 12 ... Heating lamp, 20 ... Lamp shield, 20a ... Surface side shield part, 20b ... Side shield part, 21 ... Reflector plate, 22 ... Quartz plate , 23 ... pyrometer, 24 ... susceptor, 25 ... foundation

Claims (5)

In a lamp heating apparatus for heating a substrate on which a predetermined element is formed on the surface side,
A heating lamp disposed on both the front side and the back side of the substrate;
A lamp heating device comprising: a shield member disposed on a surface side of the substrate and disposed so as to surround a surface and a side surface of the substrate. A chamber for storing the heating lamp;
A reflector provided on the inner wall of the chamber,
The shield member is disposed so as to surround the substrate so that light emitted from a heating lamp disposed on the surface side of the substrate does not reach the surface of the substrate directly or reflected by the reflector. The lamp heating apparatus according to claim 1, characterized in that: The shield member is
A surface side shield portion covering the surface side of the substrate;
It is composed of a side shield portion that covers the side surface of the substrate,
The lamp heating apparatus according to claim 1, wherein the side shield part is disposed so as to cover at least a rear side edge part of the side surface of the substrate. The lamp heating apparatus according to claim 1, wherein the shield member is made of a material that absorbs light from a heating lamp disposed on the surface side of the substrate and transmits radiant heat to the surface of the substrate. . The lamp heating apparatus according to claim 1, wherein the shield member is made of SiC.

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