| Cmp-apparatus retainer ring and manufacturing method thereof, and cmp apparatus -> Monitor Keywords |
|
|
  Cmp-apparatus retainer ring and manufacturing method thereof, and cmp apparatusUSPTO Application #: 20070298693Title: Cmp-apparatus retainer ring and manufacturing method thereof, and cmp apparatus Abstract: A retainer ring is provided which is capable of, effectively in practice, restraining the time taken for a break-in polish to the minimum. This retainer ring 8: is disposed inside of a holding head 4 in a CMP apparatus 1 which polishes a wafer W chemically and mechanically; has a ring shape so as to surround the periphery of the wafer W; presses a polish surface 3a of a polish pad 3; is made of an engineering plastic material such as PPS; and has a pressure surface 8a for pressing the polish surface 3a of the polish pad 3 whose surface roughness is a center-line average roughness (Ra) of 0.01 μm or below. (end of abstract) Agent: Arent Fox LLP - Washington, DC, US Inventor: Tsutomu Ichinoshime USPTO Applicaton #: 20070298693 - Class: 451285000 (USPTO) Related Patent Categories: Abrading, Machine, Rotary Tool, Rotary Disk, Work Rotating, Rotary Work Holder The Patent Description & Claims data below is from USPTO Patent Application 20070298693. Brief Patent Description - Full Patent Description - Patent Application Claims
TECHNICAL FIELD [0001] The present invention relates to a CMP (or chemical mechanical polishing) apparatus which polishes a wafer chemically and mechanically. Particularly, it relates to a retainer ring which is provided on (attached to) the inside of a holding head of the CMP Apparatus and surrounds the periphery of the wafer. BACKGROUND ART [0002] As a semiconductor device has more highly integrated and has performed better, its measurements in the horizontal directions (on the plane) have shortened and the structure in the vertical directions has been fined down and multi-layered. In order to realize such a fine and multi-layered structure, a semiconductor substrate (such as a silicon substrate) needs to have a high flatness (evenness). Hence, the flatness has to be heightened at the stage of a wafer, and in response to this demand, a CMP Apparatus is used. [0003] This CMP Apparatus is configured by, for example: a rotary base; a polish pad disposed on this base; and a holding head which holds a wafer and presses it onto the polish pad; a slurry supply nozzle; and the like. The holding head is formed by: a retainer ring which surrounds the periphery of the wafer; for example, an elastic film which pushes (presses) the upper surface of the wafer; an air chamber which is enclosed with this elastic film, the retainer ring and a head body; an air supply path which supplies air for pressurization into this air chamber. The retainer ring surrounds the periphery of the wafer and prevents the wafer from popping out. It also presses the polish surface of the polish pad, and flattens and fines down (suits) the polish surface of the polish pad which polishes the wafer. Hence, the retainer ring's pressure surface (surface for pressing the polish pad) needs to have a low surface roughness. [0004] On the other hand, since such a retainer ring presses the polish pad, its pressure surface itself is supposed to be polished and worn off by the polish pad. This requires that the retainer ring be regularly replaced. However, if the retainer ring's pressure surface is rough, then a predetermined polishing performance, or a desirable flatness of a wafer, cannot be obtained. In the case where the retainer ring has been exchanged, therefore, before a product wafer (a wafer which is manufactured as a product) begins to be polished, a break-in (preparatory) polish needs to be given using a newly-attached retainer ring. Specifically, this new retainer ring is attached to the holding head of the CMP Apparatus and dozens of dummy wafers (break-in wafers) are polished. After it is ascertained that a suitable polishing performance has been obtained, for the first time, a polish is given to the product wafer. This break-in polishing requires a great deal of time and labor, thus lowering the production availability of wafers. [0005] Taking this into account, in order to shorten the time taken for the break-in polishing, a retainer ring whose pressure surface is subjected to surface working (machining) so that it has a predetermined smoothness is known (e.g., refer to Patent Document 1). Specifically, in this retainer ring, its pressure surface is designed to have a surface roughness of 0.8 .mu.m or below at the maximum height (Rmax). This makes it possible to dispense with such break-in polishing. [0006] Patent Document 1: Japanese Patent Laid-Open No. 2002-126995 specification DISCLOSURE OF THE INVENTION [0006] Problems to be Solved by the Invention [0007] However, an extremely high flatness is necessary for a wafer, and such a high flatness cannot be satisfied with the retainer ring given in Patent Document 1 described above. Specifically, the pressure surface's surface roughness is some 0.8 .mu.m at the maximum height, and thus, the polish pad's polish surface cannot be flattened and fined down desirably (up to a high level). Even if a wafer is polished with this polish pad, an extremely high flatness cannot be obtained. This requires, in practice, a break-in polish which takes a long time equivalent to the time taken conventionally. Besides, in terms of the surface roughness described in Patent Document 1, the smallest value is 0.6 .mu.m at the maximum height. If the surface roughness is such a roughness level, a long-time break-in polish has to be given in the same way as the case of 0.8 .mu.m. Incidentally, according to Patent Document 1, the pressure surface's surface roughness is set to 0.8 .mu.m or below at the maximum height, so that a polishing rate and the polishing rate's uniformity within the surface can be enhanced. However, the polishing rate only expresses how fast (mm/min) a wafer can be polished, and thus, it is not supposed to indicate that a wafer can be polished so as to have a high flatness. [0008] In addition, the flatness of a wafer polished by the CMP Apparatus depends upon the material of a retainer ring and its pressure surface's surface roughness. In other words, if the retainer ring's material and its pressure surface's surface roughness are specified, that makes it possible to polish a wafer to a high flatness. However, in Patent Document 1, no mention is made of a retainer ring's material. Hence, it is unclear whether a retainer ring made of a specific material can enjoy the advantage in that its pressure surface is set to have a surface roughness of 0.8 .mu.m or below at the maximum height so that break-in polishing can be dispensed with. [0009] As described so far, according to the retainer ring and disclosure contents given in Patent Document 1, not only break-in polishing cannot be saved, but also effectively in practice, the time taken for such break-in polishing cannot be kept down to the minimum. [0010] Therefore, it is an object of the present invention to provide a retainer ring and a manufacturing method thereof which are capable of, effectively in practice, restraining the time taken for a break-in polish to the minimum. Means for Solving the Problems [0011] In order to attain the above described object, a CMP-apparatus retainer ring according to claim 1 which, in a CMP apparatus that includes a polish pad disposed on a base and a holding head holding a wafer and pressing the wafer against the polish pad and that polishes the wafer chemically and mechanically: is provided inside of the holding head; has a ring shape so as to surround the periphery of the wafer; and presses the polish surface of the polish pad, characterized in that: the retainer ring is made of an engineering plastic material; and the surface roughness of a pressure surface for pressing the polish surface of the polish pad is a center-line average roughness (arithmetic average roughness) of 0.01 .mu.m or below. [0012] A CMP-apparatus retainer ring according to claim 2, characterized in that, in the CMP-apparatus retainer ring according to claim 1: in the back surface of the retainer ring located at the back surface of the pressure surface, a portion to be held is formed; and the pressure surface is polished. [0013] A CMP-apparatus retainer-ring manufacturing method according to claim 3 for, in a CMP apparatus that includes a polish pad disposed on a base and a holding head holding a wafer and pressing the wafer against the polish pad and that polishes the wafer chemically and mechanically, manufacturing an engineering-plastic retainer ring which is provided inside of the holding head, has a ring shape so as to surround the periphery of the wafer and presses the polish surface of the polish pad, characterized by including the steps of: working a shaped surface other than a pressure surface for pressing the polish surface of the polish pad so that the shaped surface has a predetermined measurement; holding the retainer ring without applying an external-circumference pressure and an internal-circumference pressure to the retainer ring; and machining the pressure surface in this state, and polishing the pressure surface until the surface roughness thereof becomes a center-line average roughness of 0.01 .mu.m or below. [0014] A CMP-apparatus retainer-ring manufacturing method according to claim 4, characterized in that, in the CMP-apparatus retainer-ring manufacturing method according to claim 3: the polish pad disposed on the base, a pressing means for rotating the retainer ring and pressing the pressure surface thereof against the polish pad and a slurry supplying means for supplying slurry to the polish pad are provided; and the polishing is conducted by a polishing apparatus which regulates a pressure and a rotational speed given by the pressing means and a slurry supply given by the slurry supplying means. [0015] A CMP-apparatus retainer-ring manufacturing method according to claim 5, characterized in that, in the CMP-apparatus retainer-ring manufacturing method according to claim 4, before the polishing is conducted, break-in working is conducted by attaching a break-in retainer ring to the polishing apparatus. [0016] A CMP-apparatus retainer-ring manufacturing method according to claim 6, characterized in that, in the CMP-apparatus retainer-ring manufacturing method according to any one of claims 3 to 5, the machining and the polishing are conducted with holding only the side of the back surface of the retainer ring located at the back surface of the pressure surface. [0017] A CMP-apparatus retainer-ring manufacturing method according to claim 7, characterized in that, in the CMP-apparatus retainer-ring manufacturing method according to claim 6: a portion to be held is formed in the back surface of the retainer ring; the retainer ring is held by a machining jig which includes a holding portion that holds this portion to be held; and the machining is conducted in this state. [0018] A CMP-apparatus retainer-ring manufacturing method according to claim 8, characterized in that, in the CMP-apparatus retainer-ring manufacturing method according to claim 7: the machining jig holding the retainer ring is supported by a polishing jig which supports the side of the back surface of the machining jig located at the back surface of the holding portion; and the polishing is conducted in this state. [0019] A CMP-apparatus retainer-ring machining jig according to claim 9 which is the machining jig used in the CMP-apparatus retainer-ring manufacturing method according to claim 7, characterized in that the machining jig: has a flat-board shape; and in an attachment surface which comes into surface contact with the back surface of the retainer ring, includes the holding portion which holds the portion to be held that is formed in the back surface of the retainer ring. [0020] A CMP-apparatus retainer-ring machining jig according to claim 10 which is the polishing jig used in the CMP-apparatus retainer-ring manufacturing method according to claim 8, characterized in that the polishing jig: has a flat-board shape; and includes a concave supporting portion which houses the side of the back surface of the machining jig located at the back surface of the attachment surface, is fitted to the peripheral surface of the machining jig and supports the back surface of the machining jig. Continue reading... Full patent description for Cmp-apparatus retainer ring and manufacturing method thereof, and cmp apparatus Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Cmp-apparatus retainer ring and manufacturing method thereof, and cmp apparatus patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Cmp-apparatus retainer ring and manufacturing method thereof, and cmp apparatus or other areas of interest. ### Previous Patent Application: Polishing pad conditioning process Next Patent Application: Wafer polishing head Industry Class: Abrading ### FreshPatents.com Support Thank you for viewing the Cmp-apparatus retainer ring and manufacturing method thereof, and cmp apparatus patent info. IP-related news and info Results in 9.90462 seconds Other interesting Feshpatents.com categories: Software: Finance , AI , Databases , Development , Document , Navigation , Error |
||
