CN101342681A

CN101342681A - Polishing head

Info

Publication number: CN101342681A
Application number: CNA2008100792772A
Authority: CN
Inventors: 种宝春; 柳滨; 周国安
Original assignee: Beijing Semiconductor Equipment Institute
Current assignee: Beijing Semiconductor Equipment Institute
Priority date: 2008-08-28
Filing date: 2008-08-28
Publication date: 2009-01-14
Anticipated expiration: 2028-08-28
Also published as: CN101342681B

Abstract

The present invention relates to a polishing head which is used in a chemical mechanical polishing device of a semiconductor wafer. The polishing head comprises a rotating shaft, and an upper cover plate, a driving disc, a base disc, a retaining ring and a back membrane which are orderly arranged along the rotating shaft from the top to the bottom. The driving disc is fixed on a transmission shaft. The upper cover plate is fixed on the base disc and is equipped with a spring top pin. The top of the spring top pin is contacted with the inner upper surface of the upper cover plate. A drive pin is arranged between the driving disc and the base disc. The back membrane is stunk on the lower surface of the base disc, and the surrounding edge of the back membrane is provided with a fixing ring which is fixed on the base disc. The retaining ring is hung at the base disc. A movable balance joint device is arranged between the driving disc and the base disc. The polishing head has good polishing quality and high polishing planeness.

Description

Rubbing head

Technical field

The present invention relates to a kind of rubbing head, the rubbing head on particularly a kind of chemical-mechanical polisher that is used for semiconductor crystal wafer.

Background technology

Chemically mechanical polishing (CMP) is a kind of to semi-conducting material or the substrate of the material of other type carries out the planarization or the method for polishing.Development along with super large-scale integration, the increase of semiconductor crystal wafer diameter dimension, and the reducing of circuit elements device size, the components and parts volume is reduced gradually, cause the three-dimensional of circuit structure, cause the input and output lead-in wire of chip sharply to increase, chip internal line and line density rise rapidly, the cross-sectional area of line reduces gradually, and along with the increase of number of metal, photoetching requires every laminar surface necessary smooth.Chemically mechanical polishing is the unique method that realizes overall planarization at present at crystal column surface.In CMP process, rubbing head plays a part to pick up wafer and drives wafer and is rotated on the polishing pad and polishes, because the continuous increase of wafer size and pattern line density unevenness are even etc., cause the inhomogeneous situation of polishing clearance, the inhomogeneous out-of-flatness that causes crystal column surface of clearance.

Summary of the invention

Technical problem to be solved by this invention provides that a kind of quality of finish is good, polishing flatness high rubbing head.

It is as follows to address the above problem the technical scheme that is adopted:

The present invention includes turning cylinder, be provided with upper cover plate from top to bottom successively along turning cylinder, drive plate, basal disc, enclose and hold ring and notacoria, said drive plate and power transmission shaft are fixed, upper cover plate and basal disc are fixed, spring knock pin is housed on the drive plate, the upper end of spring knock pin contacts with the interior upper surface of upper cover plate, be provided with trundle between drive plate and basal disc, notacoria is covered on the lower surface of basal disc, and its border establishes retainer ring and basal disc is fixed, enclose to hold and encircle the suspending rod that is uniformly distributed with along the circumference more than three or three, the set suspension eye of suspending rod and basal disc matches, the spring-loaded plunger of corresponding setting with suspending rod is installed on the upper cover plate, and the lower end of spring-loaded plunger withstands on the body of rod of suspending rod, is provided with the activity balancing joint arrangement between drive plate and basal disc.

The said activity balancing joint arrangement of the present invention comprises annular water pocket, spherical shifting block, fixed head and chassis, said chassis and basal disc are fixed, the annular water pocket places in the groove on chassis, the upper surface of annular water pocket contacts with the lower surface of drive plate, spherical shifting block is fixed on the end of turning cylinder, is interference fits between the axis hole of spherical shifting block and fixed head.

The said basal disc lower surface of the present invention is fixed with one deck porous ceramics piece, and this layer potsherd is three distinct area that are made of concentric cake porous ceramics piece, little annular porous ceramics piece and big annular porous ceramics piece space, each ceramic block is equipped with a compressed air passage, each passage all by hydraulic quick coupler and pipeline each be communicated with along road compressed air air flue in the compressed air air flue more than the axially set two-way of turning cylinder.

Said the enclosing in the groove of holding ring of the present invention is provided with annular air-pocket, the upper surface of annular air-pocket contacts with the lower surface of retainer ring, is connected with hydraulic quick coupler and connecting pipe between road air flue in the above compressed air air flue of the axially set two-way of annular air-pocket and turning cylinder.

Said trundle of the present invention and basal disc are fixed, and match with the set U-shaped open slot of drive plate in the trundle upper end.

The invention provides the rubbing head in a kind of CMP process, adopt this rubbing head can be implemented in and obtain uniform clearance in the polishing process, realize the planarization of the polished wafer overall situation, in this rubbing head structure, adopted water pocket, according to hydraulic transmission principle, be under pressure on the water pocket, its internal pressure equates, so downforce is put on uniformly the back side of wafer by water pocket.The basal disc that will act on simultaneously on the wafer has carried out regional division, each zone all have independently can controlled pressure Compressed Gas, realization is adopted different pressure to the different zone of wafer rear, guarantee in polishing process, to be polished uniformly clearance, realize the planarization of the overall situation.Adopt spherical part to cooperate simultaneously and water pocket formation turning joint structure, under the situation of basal disc swing, downforce can be applied to wafer rear uniformly, little, the flexibility and reliability of resistance with the hole.Realize independently pressure control at the ring application air bag of keeping that wafer is played fixation, in polishing process, make the comprehensive even contact of wafer and polishing pad, reduce edge effect, realize the overall planarization in the polishing process.

Description of drawings

Fig. 1 is the structural representation of an embodiment of the present invention;

Fig. 2 is the sectional structure schematic diagram of water pocket shown in Figure 1;

Fig. 3 is the sectional structure schematic diagram of basal disc shown in Figure 1;

Fig. 4 is the sectional structure schematic diagram of retainer ring shown in Figure 1.

In the accompanying drawings: 101 turning cylinders, 102 drive plates, 103 trundles, 104 basal discs, 105 annular water pockets, 106 chassis, 107 notacorias, 108 enclose holds ring, 109 annular air-pockets, 110 upper cover plates, 111 spherical shifting blocks, 112 fixed heads, 113 retainer rings, 114 spring knock pins, 115 compressed air air flues, 116 hydraulic quick couplers, 117 spring-loaded plungers, 118 passages, 301 patty porous ceramics pieces, 302 little annular porous ceramics pieces, 303 big annular porous ceramics pieces.

The specific embodiment

The invention will be further described below in conjunction with the embodiment accompanying drawing:

Referring to accompanying drawing, the present invention includes turning cylinder 101, be provided with upper cover plate 110 from top to bottom successively along turning cylinder 101, drive plate 102, basal disc 104, enclose and hold ring 108 and notacoria 107, said drive plate 102 is fixing with power transmission shaft 101, upper cover plate 110 is fixing with basal disc 104, spring knock pin 114 is housed on the drive plate 102, the upper end of spring knock pin 114 contacts with the interior upper surface of upper cover plate 110,104 of drive plate 102 and basal discs are provided with trundle 103, notacoria 107 is covered on the lower surface of basal disc 104, and it is fixing with basal disc 104 that retainer ring 113 is established in its border, enclose and hold ring 108 suspending rod that are uniformly distributed with along the circumference more than three or three, suspending rod and basal disc 104 set suspension eyes match, the spring-loaded plunger 117 of corresponding setting with suspending rod is installed on the upper cover plate 110, the lower end of spring-loaded plunger 117 withstands on the body of rod of suspending rod, and 104 of drive plate 102 and basal discs are provided with the activity balancing joint arrangement.During work, turning cylinder 101 has downforce downwards in rotation, and drive plate 102 is fastenedly connected with turning cylinder torque is delivered on the basal disc 104 by trundle 103, and drives basal disc 104 and wafer rotation.Downforce is delivered on the basal disc through annular water pocket 105 by drive plate 102 wafer is exerted pressure, and under the effect of water pocket, downforce is applied on the wafer uniformly.The spherical shifting block 111 that is fastenedly connected with turning cylinder 101 can move and annular water pocket 105 formation activity balancing articulation structures along axis direction in the hole of fixed head 112, under the situation of basal disc swing, downforce can be applied to wafer rear uniformly, little, the flexibility and reliability of resistance.Retainer ring 113 and basal disc 104 are fastening to be fastened to notacoria 107 on the basal disc simultaneously, notacoria 107 is a soft material fluorubber film, it has big coefficient of friction to wafer and absorbs the irregular defective of wafer simultaneously, guarantees that polished surface is realized overall planarization in polishing process.Basal disc 104 lower surfaces are fixed with one deck porous ceramics piece, and this layer potsherd is three distinct area that are made of concentric cake porous ceramics piece 301, little annular porous ceramics piece 302 and big annular porous ceramics piece 303 spaces, each ceramic block is equipped with a compressed air passage 118, each passage 118 all by hydraulic quick coupler 116 and pipeline each be communicated with along road compressed air air flue in the compressed air air flue 115 more than the axially set two-way of turning cylinder 101.Carried out regional division like this on basal disc 104, all there is independently pressed gas in each zone, and pressed gas reaches in polishing process wafer rear formation uniform pressure through porous ceramics uniform pressure is applied on the wafer.Hold in ring 108 the groove and be provided with annular air-pocket 109 wafer being played enclosing of fixation,, in polishing process, make the comprehensive even contact of wafer and polishing pad, reduce edge effect, the overall planarization in the realization polishing process so that realize independently pressure control.Spring knock pin 114 is installed on drive plate 102, after upper cover plate 110 and basal disc 104 were fastenedly connected, spring knock pin 114 was compressed, under the effect of spring pressure, when turning cylinder 101 upwards lifts when driving drive plate and lifting simultaneously, basal disc 104 also is lifted simultaneously.Spring-loaded plunger 115 is installed on upper cover plate 110, after upper cover plate and basal disc tighten together, spring-loaded plunger 115 is compressed, when rubbing head picks up wafer, no pressure in the air bag 109, under the effect of spring-loaded plunger 115, keep ring 108 and move vertically and exceed 1 millimeter of notacoria, so that surround the wafer that picks up.

Referring to Fig. 1,3, in the present embodiment, basal disc 104 is with ceramic material, be fixed in the cake porous ceramics piece 301 of basal disc 104 lower surfaces, little annular porous ceramics piece 302 and big annular porous ceramics piece 303 all with basal disc 104 double sinterings together.

Claims

1, a kind of rubbing head, it is characterized in that it comprises turning cylinder (101), be provided with upper cover plate (110) from top to bottom successively along turning cylinder (101), drive plate (102), basal disc (104), enclose and hold ring (108) and notacoria (107), said drive plate (102) is fixing with power transmission shaft (101), upper cover plate (110) is fixing with basal disc (104), spring knock pin (114) is housed on the drive plate (102), the upper end of spring knock pin (114) contacts with the interior upper surface of upper cover plate (110), be provided with trundle (103) between drive plate (102) and basal disc (104), notacoria (107) is covered on the lower surface of basal disc (104), and it is fixing with basal disc (104) that retainer ring (113) is established in its border, enclose and hold ring (108) and be uniformly distributed with suspending rod more than three or three along the circumference, the set suspension eye of suspending rod and basal disc (104) matches, the spring-loaded plunger of corresponding setting with suspending rod (117) is installed on the upper cover plate (110), the lower end of spring-loaded plunger (117) withstands on the body of rod of suspending rod, is provided with the activity balancing joint arrangement between drive plate (102) and basal disc (104).

2, rubbing head according to claim 1, it is characterized in that said activity balancing joint arrangement comprises annular water pocket (105), spherical shifting block (111), fixed head (112) and chassis (106), said chassis (106) is fixing with basal disc (104), annular water pocket (105) places in the groove of chassis (106), the upper surface of annular water pocket (105) contacts with the lower surface of drive plate (102), spherical shifting block (111) is fixed on the end of turning cylinder (101), is interference fits between the axis hole of spherical shifting block (111) and fixed head (112).

3, rubbing head according to claim 1 and 2, it is characterized in that said basal disc (104) lower surface is fixed with one deck porous ceramics piece, and this layer potsherd is by concentric cake porous ceramics piece (301), three distinct area that little annular porous ceramics piece (302) and big annular porous ceramics piece (303) space constitute, each ceramic block is equipped with a compressed air passage (118), each passage (118) all by hydraulic quick coupler (116) and pipeline each be communicated with along road compressed air air flue in the compressed air air flue (115) more than the axially set two-way of turning cylinder (101).

4, rubbing head according to claim 1, it is characterized in that said enclosing is provided with annular air-pocket (109) in the groove of holding ring (108), the upper surface of annular air-pocket (109) contacts with the lower surface of retainer ring (113), is connected with hydraulic quick coupler (116) and connecting pipe between road air flue in the above compressed air air flue (115) of the axially set two-way of annular air-pocket (109) and turning cylinder (101).

5, rubbing head according to claim 1 is characterized in that said trundle (103) and basal disc (104) are fixing, matches with the set U-shaped open slot of drive plate (102) in trundle (103) upper end.