Method for generating a gas curtain of purge gas in a slit valve channel and slit valve channel

Abstract

The invention relates to a method of generating a gas curtain of purge gas in a slit valve passage of an apparatus for processing semiconductor wafers, wherein the purge gas is directed to both ends of a channel which is configured in the top of the slit valve passage and is covered by a detachable lid, and when a semiconductor wafer is transported through an aperture between the top and the bottom of the slit valve passage, the purge gas is directed in the form of a gas curtain through a slit in the bottom of the channel to the bottom of the slit valve passage.

Description

[0001] This invention provides a method for generating a gas curtain of purge gas in a slit valve channel of an apparatus for processing a semiconductor wafer, such as an apparatus for heat-processing a semiconductor wafer or an apparatus for depositing a layer on the upper side of a semiconductor wafer. The invention also provides a slit valve channel for such an apparatus.

[0002] Existing technology / problems

[0003] US Patent 2010 0 190 343A1 discloses an apparatus for processing semiconductor wafers, comprising typical modules, particularly a processing chamber, a transfer chamber, and a load lock chamber. Semiconductor wafers to be processed are fed into the modules in a predetermined order. The modules are separated by ports.

[0004] KR 10 1 875 305B1 proposes using a slit valve channel as a port, and when a semiconductor wafer is transported through the slit valve channel, a purge gas is directed onto the semiconductor wafer to protect it from particulate contamination.

[0005] US 2015 0 083 330A1 describes a slit valve channel in which purge gas is guided from top to bottom through an aperture to reach a semiconductor wafer being transported through the channel.

[0006] However, there is still a need for further improvement, as particles can accumulate in the slit valve channel, and over time, the slit valve channel itself can become a source of particles.

[0007] The purpose of this invention is to largely eliminate the risk of particulate contamination when semiconductor wafers are transported through a slit valve channel.

[0008] The object of the present invention is achieved by a method for generating a gas curtain of purge gas in a slit valve channel of an apparatus for processing semiconductor wafers, wherein the purge gas is guided to both ends of a channel disposed in the top of the slit valve channel and covered by a removable cover, and the purge gas is guided in the form of a gas curtain through a slit in the bottom of the channel to the bottom of the slit valve channel as the semiconductor wafer is conveyed through a through-hole between the top and bottom of the slit valve channel.

[0009] When the direction of movement is from top to bottom, the gas curtain preferably impacts the surface of the semiconductor wafer at a right angle.

[0010] According to another preferred embodiment of the invention, the slit at the bottom of the channel is laterally defined by an inclined wall, thereby deflecting the gas curtain directed to the bottom of the slit valve channel, causing it to impact the surface of the semiconductor wafer at an angle not equal to 90°. Preferably, if the semiconductor wafer is transported from the transfer chamber to the processing chamber or the locking chamber, the particles on the semiconductor wafer are subjected to a moving force opposite to the direction of movement of the semiconductor wafer due to the oblique impact of the gas curtain on the surface of the semiconductor wafer. In this way, particles are removed from the surface of the semiconductor wafer, and particles in the slit valve channel are moved away from the processing chamber.

[0011] The present invention also provides a slit valve channel for an apparatus for processing semiconductor wafers, the slit valve channel including a top, a bottom, and a through-hole located between the top and the bottom for conveying the semiconductor wafer along a transport path through the slit valve channel, the channel comprising:

[0012] The groove located on the upper side of the top;

[0013] A removable cover for covering the recess;

[0014] A channel located in a recess, which extends laterally to the conveying path;

[0015] A slit at the bottom of the channel for the passage of purging gas;

[0016] The holes at the top are used to supply purge gas to both ends of the channel, thereby forming a gas curtain oriented from the top to the bottom of the slit valve channel when gas is supplied.

[0017] By directing the purge gas to both ends of the channel and through slits in the channel to the semiconductor wafer, a uniform gas curtain is formed, allowing particles to be removed with the same efficiency regardless of their location on the semiconductor wafer. Because the channel can be accessed through a removable cover, critical areas where particles can accumulate and potentially become sources of contamination on the semiconductor wafer are easily accessible for cleaning.

[0018] The gas curtain extends a distance greater than the diameter of the semiconductor wafer being conveyed through the through-hole of the slit valve channel. According to one embodiment, the length of this distance, and therefore the length of the channel, is greater than 300 mm, particularly preferably 320 mm. According to one embodiment, the width of the slit at the bottom of the channel is adjusted to achieve the desired flow rate of the gas curtain.

[0019] According to a preferred embodiment, the slit at the bottom of the channel has a vertical wall that laterally defines the slit, such that the gas curtain impacts the surface of the semiconductor wafer at a 90° angle.

[0020] According to another preferred embodiment, the slit at the bottom of the channel has walls that laterally define the slit and are arranged in an inclined manner. The gas curtain is deflected by the walls, causing it to impact the surface of the semiconductor wafer at an angle not equal to 90°.

[0021] Preferably, the cover is removed at predetermined intervals, for example during maintenance of an apparatus used to handle semiconductor wafers, and then the cover, the recesses and channels that house the cover, are cleaned and dried. Cleaning and drying can be performed relatively quickly without any special effort.

[0022] The cap fills the groove and is detachably secured to the upper side of the top of the slit valve passage. According to one embodiment, the fastening device is a screw, preferably a plastic or ceramic screw. According to one embodiment, a seal is also provided to prevent purge gas from passing between the cap and the groove.

[0023] The slit valve passage has a front side and a rear side. According to one embodiment, the front side is the side adjacent to the transfer chamber, and the rear side is the side adjacent to the processing chamber or locking chamber.

[0024] At the top of the slit valve channel, two holes are provided for supplying purge gas to both ends of the channel. According to one embodiment, the holes are located on the rear side of the slit valve channel, in the area of ​​the two upper circular corners on the rear side.

[0025] The slit valve passage can be closed by a door. According to one embodiment, the door closes the through-hole on the front side of the slit valve passage.

[0026] The slit valve channel is part of an apparatus for processing semiconductor wafers. According to one embodiment, the apparatus is for depositing an epitaxial layer on a substrate wafer, preferably for depositing a silicon epitaxial layer on a monocrystalline silicon substrate wafer. According to another embodiment, it is an apparatus for thermally processing semiconductor wafers, preferably for thermally processing monocrystalline silicon semiconductor wafers.

[0027] The invention will now be further described with reference to the accompanying drawings. Attached Figure Description

[0028] Figure 1 A preferred embodiment of the slit valve passage is shown in perspective.

[0029] Figure 2 It shows that according to Figure 1 The slit valve passage, in which the cover is removed.

[0030] Figure 3 It is based on Figure 1 A view of the rear side of the slit valve channel, which has an active gas curtain.

[0031] Figure 4It is based on Figure 1 A schematic diagram of the slit valve passage viewed from the side.

[0032] Figure 5 It is based on Figure 1 A cross-sectional view of the slit valve passage in the preferred embodiment.

[0033] Figure 6 It is based on Figure 1 A cross-sectional view of the slit valve passage in another preferred embodiment.

[0034] List of reference numerals used

[0035] 1. Slit valve passage

[0036] 2 Top

[0037] 3. Bottom

[0038] 4 through holes

[0039] 5. Rear side

[0040] 6 lids

[0041] 7 holes

[0042] 8 grooves

[0043] 9 channels

[0044] 10 end

[0045] 11. Gas curtain

[0046] 12 Conveying Path

[0047] 13 walls

[0048] Module A

[0049] Module B

[0050] Detailed description of exemplary embodiments according to the present invention

[0051] Figure 1 A preferred embodiment of the slit valve channel 1 is shown in perspective. The slit valve channel 1 includes a top 2, a bottom 3, and a through hole 4 located between the top and the bottom. The rear side 5 of the slit valve channel 1 is visible in this view. A removable cover 6 is fastened to the upper side of the top with screws. Two holes 7 are provided in the area at the upper corners of the two centers of the rear side 5 of the slit valve channel 1, through which purge gas is guided to both ends of the channel covered by the cover 6. Arrows indicate the flow direction of the purge gas.

[0052] Figure 2 It shows that according to Figure 1The slit valve passage 1 has a cover 6 removed. A groove 8 is provided on the upper side of the top 2, into which the cover 6 is securely fitted. A channel 9 with two ends 10 is engaged in the groove, the channel extending almost across the width of the through hole 4 and opening into the slit at the bottom (not shown).

[0053] Figure 3 It is based on Figure 1 A view of the rear side 3 of the slit valve passage, which has an active gas curtain 11 for purging gas.

[0054] Figure 4 It is based on Figure 1 A schematic diagram of the slit valve channel from the side, wherein the rear side 5 of the slit valve channel 1 is adjacent to module A of the apparatus for processing semiconductor wafers, and the front side of the slit valve channel 1 is adjacent to module B of the apparatus. Arrows indicate the direction of movement of the door (not shown) used to close the through-hole 4. For example, module A is a processing chamber or loading chamber, and module B is a transfer chamber.

[0055] Figure 5 This is a cross-sectional view of the slit valve channel in the preferred embodiment, wherein the slit at the bottom of the channel is defined by a vertical wall 13. A gas curtain impacts the surface of the semiconductor wafer at a 90° angle.

[0056] Figure 6 This is a cross-sectional view of the slit valve passage in another preferred embodiment, wherein the slit at the bottom of the channel is defined by an inclined wall 13. Due to this wall, the gas curtain deflects in the direction indicated by the arrow.

[0057] The above description of exemplary embodiments should be understood as exemplary. The disclosure thus made enables those skilled in the art to understand the invention and its related advantages, while also including variations and modifications to the described structures and methods that are readily apparent to those skilled in the art. Therefore, all such variations and modifications, and their equivalents, are covered by the scope of the claims.

Claims

1. A method for generating a gas curtain of purge gas in a slit valve channel (1) of an apparatus for processing semiconductor wafers, wherein The purge gas is guided to both ends of a channel (9) which is configured in the top (2) of the slit valve channel (1) and covered by a removably fixed cover (6). When the semiconductor wafer is conveyed through the through hole (4) between the top (2) and bottom (3) of the slit valve channel (1), the purge gas is guided in the form of a gas curtain (11) through the slit in the bottom of the channel (9) to the bottom of the slit valve channel (1).

2. The method according to claim 1, wherein the cover (6) is removed before or after the gas curtain (11) is generated, and the cover (6), the recess (8) receiving the cover, and the channel (9) are cleaned.

3. The method according to claim 1 or 2, wherein the gas curtain (11) guided to the bottom (3) of the slit valve channel (1) impacts the surface of the semiconductor wafer at an angle of 90°.

4. The method according to claim 1 or 2, wherein the slit in the bottom of the channel (9) is laterally defined by an inclined wall (13), thereby deflecting the gas curtain (11) leading to the bottom (3) of the slit valve channel (1) so that it impacts the surface of the semiconductor wafer at an angle not equal to 90°.

5. A slit valve channel (1) for a device for processing a semiconductor wafer, comprising a top (2), a bottom (3), and a through-hole (4) located between the top (2) and the bottom (3), the through-hole (4) for conveying the semiconductor wafer through the slit valve channel (1) along a transport path (12), comprising: The groove (8) is located on the upper side of the top (2); A cover (6) for removably fixing to cover the groove (8); A channel (9) located in the groove (8) extends transversely to the conveying path (12); A slit in the bottom of the channel (9) is used for the passage of purging gas; The hole (7) located in the top (2) is used to supply the purge gas to both ends (10) of the channel (9); thereby, when the purge gas is supplied, a gas curtain (11) oriented from the top (2) to the bottom (3) of the slit valve channel (1) is formed.

6. The slit valve passage according to claim 5, characterized in that... The vertical wall (13) laterally defines the slit.

7. The slit valve passage according to claim 5, characterized in that... The sloping wall (13) laterally defines the slit.

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