Lift pin for substrate processing
Lift pins and devices having lift pins are provided. According to an aspect, a lift pin may have a tapered distal portion. According to another aspect, a lift pin may have two portions threadedly engaged with each other. According to yet another aspect, a lift pin may be mounted to a lifting plate with slackness.
1. An apparatus comprising:
a lift pin comprising:
a distal end; and
a proximal end; and
a lifting plate fixed to the proximal end of the lift pin, wherein the lift pin is fixed to the lifting plate with slackness to allow movement of the lift pin in a lateral direction parallel to the lifting plate, wherein, for providing the slackness, a proximal part of the lift pin traverses a hole of the lifting plate, a diameter of the proximal part being at least 10% smaller than a diameter of the hole of the lifting plate, wherein the lifting plate is fixed to the lift pin such that the lifting plate and the lift pin move together in a vertical direction when the lifting plate is moved in the vertical direction perpendicular to the lifting plate,
wherein the lift pin comprises a distal portion comprising the distal end and a proximal portion comprising the proximal end, the distal portion comprising a first thread at an end opposite the distal end and the proximal portion comprising a second thread at an end opposite the proximal end, and
wherein the first thread is configured to engage the second thread with slackness in the thread connection measured orthogonal to a direction defined by a direction between the distal end and the proximal end, the slackness in the thread connection being between 40 μm to 60 μm.
2. The apparatus of claim 1 , wherein the lift pin further comprises a step between the distal end and the proximal end, a diameter of the lift pin at a side of the step closer to the distal end being greater than a diameter of the lift pin at a side of the step closer to the proximal end.
3. The apparatus of claim 1 , wherein the first thread is one of an internal thread and an external thread, and the second thread is the other one of an internal thread and an external thread.
4. The apparatus of claim 1 , wherein the first thread and the second thread enable a length adjustment of the lift pin.
5. The apparatus of claim 1 , wherein at least one of the first thread and the second thread is made of anodized aluminum, stainless steel with non-standard diameter or plastic with non-standard diameter.
6. The apparatus of claim 1 , wherein the lift pin is provided with a snap ring on a proximal side of the hole of the lifting plate.
7. The apparatus of claim 1 , wherein the lift pin is provided with a plate on a distal side of the lifting plate.
8. The apparatus of claim 7 , wherein the plate is accommodated in a recess of the lifting plate, the recess being dimensioned such that a rotating motion of the plate within the recess is limited.
9. The apparatus of claim 1 , further comprising a rotation limiting mechanism to limit a rotation of the lift pin within the lifting plate.
10. The apparatus of claim 1 , wherein the lift pin further comprises a tapered portion at the distal end, a diameter of the tapered portion decreasing from the distal end towards the proximal end, and wherein a tapering angle of the tapered portion is less than 20°.
11. The apparatus of claim 10 , wherein the tapering angle is less than 10°.
12. The apparatus of claim 1 , wherein the apparatus is configured to move relative to a chuck.
13. An apparatus comprising:
a lifting plate comprising a hole;
a lift pin, wherein a proximal portion of the lift pin traverses the hole of the lifting plate, wherein a diameter of the proximal portion is at least 10% smaller than a diameter of the hole to provide a slackness, and wherein the lift pin is rotatable with respect to the lifting plate; and
a rotation limiting mechanism to limit a rotating of the lift pin with respect to the lifting plate to a predefined angular range smaller than a full turn of the lift pin,
wherein the rotation limiting mechanism comprises a plate of the lift pin, wherein the plate is accommodated in a recess of the lifting plate, and wherein the recess is dimensioned such that a rotating motion of the plate within the recess is limited such that, in a first position, a perimeter of the plate is spaced apart from a perimeter of the recess and, in a second position, at least a part of the perimeter of the plate is in contact with the perimeter of the recess.
14. The apparatus of claim 13 , wherein the diameter of the proximal portion is at least 25% smaller than a diameter of the hole.
15. The apparatus of claim 13 , wherein the lift pin comprises a tapered distal end.
16. The apparatus of claim 13 , wherein a length of the lift pin is adjustable.
17. The apparatus of claim 13 , further comprising a chuck, the chuck comprising a through hole to accommodate a part of the lift pin.
18. A lift pin comprising:
an elongated distal portion comprising a first thread; and
an elongated proximal portion comprising a second thread,
wherein the first thread engages the second thread such that a longitudinal direction of the elongated distal portion corresponds to a longitudinal direction of the elongated proximal portion,
wherein the first thread engages the second thread with a slackness measured orthogonal to the longitudinal direction, the slackness being between 20 μm to 150 μm,
wherein the lift pin further comprises a tapered portion at the elongated distal portion, a diameter of the tapered portion decreasing from the elongated distal portion towards the elongated proximal portion, and
wherein a tapering angle of the tapered portion is less than 20°.
19. The lift pin of claim 18 , wherein the first thread and the second thread provide a length adjustment of the lift pin.
20. The lift pin of claim 18 , wherein the tapering angle is less than 10°.