CN101030538A - Plasma etching apparatus and method - Google Patents
Plasma etching apparatus and method Download PDFInfo
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- CN101030538A CN101030538A CN 200710085802 CN200710085802A CN101030538A CN 101030538 A CN101030538 A CN 101030538A CN 200710085802 CN200710085802 CN 200710085802 CN 200710085802 A CN200710085802 A CN 200710085802A CN 101030538 A CN101030538 A CN 101030538A
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Abstract
The object of the present invention is to ensure even etching speed in the etching plane and control the etching shape when silicon etching is carried out with a sort of etching resist as mask. A plurality of gas blow-outs (22) are arranged on the lower part (20b) of a nozzle (20); annular bulge parts (40) are arranged on the circumference of the gas blow-outs (22), facing a support work table (2). In addition, the gas blow-outs (22) are arranged centrally near the center of the lower part (20b) of the nozzle (20), so that all of the gas blow-outs (22) are within a area (S) smaller than the area of the wafer (W).
Description
Technical field
The present invention relates to plasma-etching apparatus and plasma-etching method, in detail, relate to the plasma-etching apparatus and the plasma-etching method that when using plasma that handled object is carried out etching, use.
Background technology
In the manufacture process of semiconductor device, for example in the manufacturing of three-dimensional installing device, carry out on silicon substrate, forming the silicon etching of groove that through hole that the distribution of the above degree of depth of 100 μ m uses or mechanical structure uses etc.
In above-mentioned silicon etching, generally adopt following engraving method: at first, with form figuratum resist as mask to SiO
2Oxide-films such as film carry out etching, after peeling off resist, use for example SF
6/ O
2Gas is as etching gas, with SiO
2Film carries out etching as mask to silicon.But, recently,, studied with resist and directly silicon carried out etching method as mask in order to reduce process number.
In addition, in the manufacture process of three-dimensional installing device, after the silicon etching, in order to be easy to carry out the necessary operations such as dielectric film, formation seed metal (seed metal) layer and copper facing that on etch-hole, form, need sometimes the shape of etch-hole is formed taper, just sidewall tilted in the diameter mode littler than hole upper part diameter of bottom, hole.But, carrying out as mask under the etched situation of silicon with resist, there are the uniformity be difficult to obtain as the semiconductor die of processed substrate the etch-rate (that is the degree of depth in hole) in unilateral and the controlled problem of shape.More particularly, because the etch-rate of the central portion of semiconductor wafer (center) is faster than the etch-rate of periphery (edge), so, the hole of central portion has and forms than the trend of the Kong Yaoshen of periphery, in addition, periphery is compared with central portion, and sidewall does not tilt, and has the trend that forms subvertical hole.
Etching about dielectric film, in order to realize fine etching at high speed, following technology has been proposed: go up at the shading ring (shield ring) of the periphery of upper electrode outstanding protuberance is set downwards, in the diffusion that prevents plasma, carry out the technology (for example, patent documentation 1) of etch processes.
In addition, in order to control gas spray volume and the gas flow from shower nozzle, proposed to relate to the technology of the shower nozzle that comprises gate (shutter) device, this valve system has the opening (for example, patent documentation 2) that can freely dwindle with the enlarged openings diameter.
Patent documentation 1: Japanese kokai publication hei 8-335568 communique (for example, Fig. 2)
Patent documentation 2: Japanese kokai publication hei 10-60673 communique (for example, Fig. 1)
In above-mentioned patent documentation 1, patent documentation 2, the protuberance of shading ring, the valve system of shower nozzle have been proposed, but in using the silicon etching of resist, do not consider fully to realize the uniformity of etch-rate and the etching shape is controlled to be taper as mask.
Summary of the invention
The objective of the invention is to, when carrying out the silicon etching as mask, guarantee the inner evenness of etch-rate, control the etching shape simultaneously with resist.
In order to address the above problem, a first aspect of the present invention provides a kind of plasma-etching apparatus, it is characterized in that, comprising: be used for handled object is carried out process chamber plasma etch process, can decompression exhaust;
The mounting table of mounting handled object in above-mentioned process chamber;
The processing gas that disposes, will be used to generate plasma relatively with above-mentioned mounting table imports the shower nozzle in the above-mentioned process chamber;
Below above-mentioned shower nozzle, to the outstanding in the form of a ring annular convex that is provided with of above-mentioned mounting table; With
The inboard central portion of the above-mentioned annular convex below above-mentioned shower nozzle, distributing is provided in area than a plurality of gas squit holes in the little zone of the area of handled object.
In the plasma-etching apparatus of first aspect, below shower nozzle, be provided with to the outstanding in the form of a ring annular convex that is provided with of mounting table, and the inboard central portion concentrated area in this annular convex sets the gas squit hole, therefore, utilize annular convex to make its inboard plasma form the pressure equalization in space, thus, near the major control annular convex the plasma density and the amount of deposit, and, by the gas squit hole is concentrated on central portion, the gas flow rate of handled object central portion top is improved, suppress the growing amount of the etchant of central portion.As a result, can realize the inner evenness and the control etching shape of etch-rate.
In above-mentioned first aspect, preferred: as lower electrode, as upper electrode, to constitute a pair of comparative electrode with above-mentioned shower nozzle with above-mentioned mounting table.In addition, preferably with respect to the diameter L of handled object, the external diameter of above-mentioned annular convex is 1.1L～1.5L, and the internal diameter of preferred above-mentioned annular convex is greater than the diameter L of handled object.Thus, form its all plasma of covering on the top of handled object and form the space, thereby guarantee etched inner evenness.
In addition, the height of preferred above-mentioned annular convex is more than 0.4 times of distance from above-mentioned mounting table to above-mentioned shower nozzle.Thus, can access the pressure effect of uniform that the conductance (conductance) that makes air-flow reduces and make the space that is surrounded by annular convex.
In addition, preferred: with respect to the diameter L of handled object, the above-mentioned gas squit hole forms in the zone of the area with 0.3L * 0.3L～0.7L * 0.7L.Thus, can make the gas flow rate of superjacent air space of central portion of processed substrate enough big.
A second aspect of the present invention provides a kind of plasma-etching method, it is characterized in that:
Use the plasma-etching apparatus of above-mentioned first aspect,
For having with silicon is the handled object of the etched layer of main component and the resist layer that is patterned in advance that forms on upper strata of this etched layer, and effect is by containing SF
6And O
2The plasma that generates of processing gas, be mask with above-mentioned resist, etched layer is carried out plasma etch process.
In above-mentioned second aspect, preferred above-mentioned etched layer is silicon substrate or silicon layer.
A third aspect of the present invention provides a kind of control program, it is characterized in that: when moving on computers, control above-mentioned plasma-etching apparatus, implement the plasma-etching method of above-mentioned second aspect.
A fourth aspect of the present invention provides a kind of storage medium of embodied on computer readable, and it is to store the storage medium of the embodied on computer readable of the control program of operation on computers, it is characterized in that:
Above-mentioned control program is controlled above-mentioned plasma-etching apparatus when operation, implement the plasma-etching method of above-mentioned second aspect.
Plasma-etching apparatus of the present invention comprises: below shower nozzle, to the outstanding in the form of a ring annular convex that is provided with of mounting table; Be provided in area than a plurality of gas squit holes in the little zone of the area of handled object with inboard central portion, distribution in this annular convex, therefore, by using this plasma Etaching device, can carry out the etching of controlled excellence of the etching shapes such as formation of the uniformity of the etch depth in the processed dignity and for example taper.Therefore, this plasma Etaching device can advantageously utilize aspect the high semiconductor device of fabrication reliability, also can tackle the miniaturization of design rule of semiconductor device and highly integrated.
Description of drawings
Fig. 1 is the sectional view that expression is suitable for implementing the magnetron RIE plasma-etching apparatus of engraving method of the present invention.
Fig. 2 is the horizontal sectional view of the dipole annular magnet (dipole ring magnet) under the state that schematically shows around the chamber of the device that is configured in Fig. 1.
Fig. 3 is used to illustrate the electric field that forms and the schematic diagram in magnetic field in chamber.
Fig. 4 is the figure that is used to illustrate the configuration of annular convex and gas squit hole.
Fig. 5 is plane graph configuration, below the shower nozzle that is used to illustrate annular convex and gas squit hole.
Fig. 6 is the schematic section of near surface of semiconductor wafer of representing to carry out the state of plasma etching.
Fig. 7 is the schematic section of the near surface of the semiconductor wafer behind the expression plasma etching.
Symbol description
1 chamber (container handling)
2 support table (electrode)
12 gas extraction system
15 high frequency electric sources
17 cryogen chamber
18 gas introducing mechanisms
20 shower nozzles (electrode)
22 gas squit holes
23 treating-gas supply systems
24 dipole annular magnets
40 annular convex
101 silicon substrates
102 resists
The W wafer
Embodiment
Below, with reference to accompanying drawing, preferred implementation of the present invention is described.Fig. 1 is the sectional view of the magnetron RIE plasma-etching apparatus 100 of expression first execution mode of the present invention.This plasma Etaching device 100 constitutes airtightly, forms by what the top 1a of minor diameter and large diameter bottom 1b constituted to have the cylindric of step, has wall portion chamber for example made of aluminum (container handling) 1.
Be provided with support table 2 in this chamber 1, it flatly supports the wafer W as the single crystalline Si substrate, as handled object.Support table 2 for example is made of aluminium, is supported by the brace table 4 of conductor by insulation board 3.In addition, the periphery above support table 2 is provided with by the material beyond the Si, the quartzy focusing ring 5 that forms for example.Above-mentioned support table 2 and brace table 4 can utilize the ball screw framework that comprises ball-screw 7 to carry out lifting, and the drive part of the below of brace table 4 is covered by the bellows (bellows) 8 of stainless steel (SUS) system.Arranged outside at bellows 8 has bellows cover (bellows cover) 9.In addition, the arranged outside of above-mentioned focusing ring 5 has baffle plate (baffle plate) 10, by this baffle plate 10, brace table 4 and bellows 8, with chamber 1 conducting.Chamber 1 is grounded.
Be formed with exhaust outlet 11 on the sidewall of the bottom of chamber 1 1b, gas extraction system 12 is connected with this exhaust outlet 11.So,, can will be decompressed to the specified vacuum degree in the chamber 1 by making the vacuum pump work of gas extraction system 12.On the other hand, at the sidewall upside of the bottom of chamber 1 1b, be provided with and be used for the gate valve 13 that moving into of switch wafer W taken out of mouthful.
The high frequency electric source 15 that plasma forms usefulness is connected with support table 2 by adaptation 14, supplies with the High frequency power of assigned frequency to support table 2 from this high frequency electric source 15.On the other hand, relative with it and be provided with the back in parallel to each other with the shower nozzle 20 that describes in detail with it above support table 2, this shower nozzle 20 is grounded.Thereby support table 2 and shower nozzle 20 play a role as pair of electrodes.
The surface of support table 2 is provided with the electrostatic chuck 6 that is used for Electrostatic Absorption and keeps wafer W.This electrostatic chuck 6 constitutes and have electrode 6a between insulator 6b, and DC power supply 16 is connected with electrode 6a.So, apply voltage from power supply 16 to electrode 6a, thus, utilize electrostatic force, for example Coulomb force absorption wafer W.
Be provided with cryogen chamber 17 in the inside of support table 2, in this cryogen chamber 17, cold-producing medium imports from cold-producing medium ingress pipe 17a, discharge from refrigerant discharge leader 17b, thereby circulate, it is cold and hot to transmit to wafer W by support table 2, thus, the treated side of wafer W is controlled to be desired temperatures.
In addition, utilize gas introducing mechanism 18 refrigerating gas to be imported between the back side of the surface of electrostatic chuck 6 and wafer W by its gas supply pipe line 19, even make that chamber 1 is maintained under the vacuum by gas extraction system 12 exhausts, also can utilize the cold-producing medium of circulation in cryogen chamber 17, wafer W is cooled off effectively.By such importing refrigerating gas, can transmit the cold and hot of cold-producing medium to wafer W effectively, improve the cooling effectiveness of wafer W.As refrigerating gas, for example can use He etc.
Above-mentioned shower nozzle 20 relatively is provided with support table 2 in the top wall portion of chamber 1.The following 20b of this shower nozzle 20 is provided with a plurality of gas squit holes 22, is provided with the outstanding annular convex 40 that is made of wall body cylindraceous that is provided with of support table 2 towards relative configuration around these gas squit holes 22.Annular convex 40 can be provided with integratedly with shower nozzle 20, also can be below shower nozzle 20 the different endless member of installation and shower nozzle 20.Annular convex 40 is made of the material identical with shower nozzle 20, for example aluminium etc.In addition, can on the surface of annular convex 40, similarly carry out pellumina with shower nozzle 20 and handle or form Y as required
2O
3Etc. ceramic sputtered films of bismuth.
In addition, has gas introduction part 20a on the top of shower nozzle 20.And portion is formed with space 21 within it.Gas supplying tubing 23a is connected with gas introduction part 20a, and the other end of this gas supplying tubing 23a is connected with the treating-gas supply system 23 of supplying with the processing gas that is made of etching gas and diluent gas.
As etching gas, the preferred use contained SF
6And O
2Gas.With regard to SF
6Gas, the density of the F atom that generates in the plasma is big several times of gas than other fluorine, and SF
6In the S atom that contains have the oxidation that prevents the Si surface, promote etched effect, therefore, can be applicable to the silicon etching.
In addition, O
2Pasc reaction in gas and the silicon substrate forms silicon oxide layer (SiO on sidewall
x), have the effect of promotion to the anisotropic etching of vertical direction.
In addition, the etching gas as beyond above-mentioned can use for example S
2F
10, NF
3, SiF
4Deng.
Such processing gas, sprays from gas squit hole 22 via the space 21 that gas supplying tubing 23a and gas introduction part 20a arrive shower nozzle 20 from treating-gas supply system 23.
On the other hand, around the 1a of the top of chamber 1, dispose dipole annular magnet 24 with one heart shape.Shown in the horizontal sectional view of Fig. 2, dipole annular magnet 24 is by constituting on the shell (casing) 32 that a plurality of anisotropy segmentations (segment) columnar magnet 31 is installed in the magnetic of ring-type.In this example, form columned 16 anisotropy segmentation columnar magnets 31 and be configured to ring-type.In Fig. 2, the arrow that shows in anisotropy segmentation columnar magnet 31 is represented magnetized direction, and is as shown in the drawing, and the direction of magnetization of a plurality of anisotropy segmentation columnar magnets 31 is staggered bit by bit, as a whole, formation uniform horizontal magnetic field B facing one direction.
Thereby, schematically shown in Figure 3, in the space between support table 2 and shower nozzle 20, utilize high frequency electric source 15 to form the electric field EL of vertical, and utilize dipole annular magnet 24 to form horizontal magnetic field B, utilize the crossed electric and magnetic field that forms like this to generate magnetron discharge.Thus, form the plasma of the etching gas of higher-energy state, wafer W is etched.
In addition, each component part of plasma-etching apparatus 100 forms and is connected and is subjected to the structure of its control with the processing controller that possesses CPU (process controller) 50.Carry out the keyboard of input operation etc. of order and the user interface 51 that the operational situation of plasma-etching apparatus 100 is visual and display of showing etc. constitute by the process management person for managing plasma Etaching device 100, be connected with processing controller 50.
In addition, storage part 52 is connected with processing controller 50, this storage part 52 stores scheme (recipe), records the control program that is used under the control of processing controller 50 realizing the various processing undertaken by plasma-etching apparatus 100 and treatment conditions data etc. in this scheme.
So, as required, according to from indication of user interface 51 etc., from storage part 52, access scheme arbitrarily, and it is moved in processing controller 50, thus, under the control of processing controller 50, the processing of in plasma-etching apparatus 100, expecting.In addition, such scheme can utilize under the state in being stored in the storage medium of CD-ROM, hard disk, floppy disk and flash memory embodied on computer readable such as (flash memory) for example, perhaps, also can install, for example transmit at any time and utilize by special circuit from other.
Then, with reference to Fig. 4 and Fig. 5, the annular convex 40 of shower nozzle 20 and the configuration of gas squit hole 22 are described.
By annular convex 40 is set below shower nozzle 20, can makes from the conductance of the air-flow of gas squit hole 22 ejection of shower nozzle 20 and reduce, and can make the pressure distribution in the space that surrounds by annular convex 40 even.The result; in the space that surrounds by annular convex 40, especially near protuberance, by the control plasma density and as the amount of the pasc reaction product in the source of deposit; the amount of the sidewall diaphragm in the etch-hole can be controlled, thereby the etching shape of silicon positive taper can be controlled to be.
The overhang of annular convex 40 (highly: H) be preferably up and down interelectrode distance (gap) G, be the top (under the situation of Fig. 1 of support table 2, be the top of electrostatic chuck 6) and the following 20b of shower nozzle 20 between more than 0.4 times of distance, for example 0.4～0.8 times.If the overhang H of annular convex 40 less than 0.4 times of clearance G, then can not reduce the conductance of air-flow fully, make the effect of pressure equalization in the space that surrounds by annular convex 40 little.In addition, if overhang H surpasses 0.8 times of clearance G, then the conductance of air-flow is low excessively, and the disassociation of etching gas composition is exceedingly carried out, and etching characteristic might worsen.In addition, clearance G is preferably for example 25～50mm.
In addition, consider from the viewpoint that the conductance of the air-flow that makes wafer W top reduces, with respect to the diameter L of wafer W, the external diameter L of annular convex 40
1Be preferably 1.1L～1.5L.In addition, preferably with external diameter L
1Be set at diameter less than the mounting surface of the level of mounting wafer W in support table 2.In addition, support table 2 is provided with under the situation of focusing ring 5, preferably with the external diameter L of annular convex 40
1Be set at external diameter L less than focusing ring 5
4
On the other hand, consider, preferably with the internal diameter L of annular convex 40 from the viewpoint that above wafer W, forms uniform plasma space
2Be set at diameter L greater than wafer W.
In addition, in the present embodiment, as shown in Figure 5, below shower nozzle 20, near the central portion of 20b, concentrate to be provided with gas squit hole 22.That is, below shower nozzle 20, among the 20b,, gas squit hole 22 is concentrated be distributed in (L on one side with respect to the diameter L of wafer W
3) be that roughly the tetragonal region S of 0.3L～0.7L (is S=L
3* L
3) in, below shower nozzle 20, among the 20b, in the zone relative, gas squit hole 22 is not set with the periphery of wafer W.Like this, in the present embodiment, gas squit hole 22 is concentrated near the central authorities of following 20b of shower nozzle 20, make all gas squit holes 22 all be present in area than in the little region S of the area of wafer W.In addition, in Fig. 5,, be illustrated in the shower nozzle of gas squit hole 22 the gas squit hole 22 that should form in the outside of region S with common configuration with imaginary line in order to do reference.
By gas squit hole 22 is concentrated the central portions that are formed on shower nozzle 20, can increase the gas flow of superjacent air space of the central portion of wafer W.So, central portion superjacent air space in wafer W, the flow velocity of gas is accelerated, as a result, the time of staying of free radical (residence time) shortens, therefore, in this space, be suppressed to the disassociation as the F free radical of etchant, the etch-rate of silicon reduces, and the uniformity in the face of wafer W improves.
In addition, the distribution of the gas squit hole 22 of shower nozzle 20, can by filling can embed in the gas squit hole 22 in the zone relative with the periphery of wafer W parts so that its obturation regulate thus.For example, by making gas squit hole 22 obturations of the position of representing with imaginary line in Fig. 5, configuration (distributed areas) that can the adjustments of gas squit hole makes it concentrate on the central authorities of shower nozzle 20.
Then, illustrate and use the plasma-etching apparatus that constitutes like this, silicon (monocrystalline silicon substrate or polysilicon layer) is carried out the engraving method of the present invention of plasma etching.
At first, open gate valve 13, move into wafer W in the chamber 1 and after being positioned on the support table 2, make support table 2 rise to illustrated position, utilize the vacuum pump of gas extraction system 12, by carrying out exhaust in 11 pairs of chambers 1 of exhaust outlet.
Then, from treating-gas supply system 23, with the flow of regulation, the processing gas that will comprise etching gas and diluent gas imports in the chamber 1, make the pressure that reaches regulation in the chamber 1, under this state, supply with the High frequency power of regulation to support table 2 from high frequency electric source 15.At this moment, by apply the voltage of regulation to the electrode 6a of electrostatic chuck 6 from DC power supply 16, for example utilize the Coulomb force that wafer W absorption is remained on the electrostatic chuck 6, and, between as the shower nozzle 20 of upper electrode and support table 2, form high-frequency electric field as lower electrode.Because utilize dipole annular magnet 24 between shower nozzle 20 and support table 2, to be formed with horizontal magnetic field B, so, in the interelectrode processing space that wafer W exists, form crossed electric and magnetic field, utilize the Electron drift (drift) that produces therefrom, generate magnetron discharge.So the plasma of the etching gas that utilization is formed by this magnetron discharge carries out etching to wafer W.At this moment, owing to the pressure of the inner space of annular convex 40 as mentioned above rises and near the rising of the gas flow rate that caused central authorities by gas squit hole 22 centralized configuration, uniformity and etching shape controlled of etch-rate in wafer face becomes good.
In order to make etched shape good, the temperature of regulating wafer W also is effective.Therefore, be provided with cryogen chamber 17, cold-producing medium circulated in this cryogen chamber 17, its cold and hot by support table 2 to the wafer W transmission, thus, the treated side of wafer W is controlled to be desired temperatures.
With regard to the high frequency electric source 15 that plasma generates usefulness, suitably set its frequency and output for the plasma that forms expectation.In the silicon etching, from improve wafer W directly over the viewpoint of plasma density consider, preferably with frequency setting for for example 40MHz or more than it.
Dipole annular magnet 24 for improve wafer W directly over plasma density and apply magnetic field to support table 2 and the processing space between the shower nozzle 20 as comparative electrode, but, in order to bring into play its effect effectively, preferably this dipole annular magnet is the magnet that forms the intensity in the magnetic field more than the 10000 μ T (100G) in handling the space.Though think that magnetic field is strong more, the effect that improves plasma density increases more, considers from the viewpoint of fail safe, and preferred magnetic field intensity is below the 100000 μ T (1kG).
It is as follows to be used to use plasma-etching apparatus 100 to carry out the etched optimum condition of silicon.With regard to the flow of etching gas, SF
6=100～1000mL/min (sccm), O
2=0～500mL/min (sccm) considers that from the viewpoint of etching shape control preferably making its flow-rate ratio is SF
6/ O
2=3/1～2/1.
From guaranteeing that sufficient etch-rate and mask select the viewpoint of ratio to consider, preferably making processing pressure is 10～60Pa (75mTorr～450mTorr).
In addition, to select ratio, the frequency that preferably makes the high frequency of high frequency electric source 15 be that 40MHz is above, to make high frequency power be 0.5～2.0kW in order to obtain sufficient etch-rate and mask.
In addition, preferably making the intensity in the magnetic field that is formed by dipole annular magnet 24 is 10000 μ T～30000 μ T.
In addition, from controlling the etching shape well, being that anisotropic viewpoint considers that preferably the temperature with wafer W for example is adjusted into about-15～30 ℃.
Fig. 6 and Fig. 7 are the cross section structure that schematically shows the near surface of handled objects 110 such as wafer W for the plasma-etching method that uses plasma-etching apparatus 100 of the present invention is described.
As shown in Figure 6, in handled object 110, on silicon substrate 101, have and be pre-formed figuratum resist 102.In addition, also not shown antireflection film can be set under resist 102.So, use plasma-etching apparatus 100,, and, make the action of plasma of handling gas in handled object 110, thereby it is implemented the silicon etching as mask with resist 102 based on its pattern.As handling gas, can use for example SF
6/ O
2The etching condition of this moment as mentioned above.
By this silicon etching, as shown in Figure 7, on silicon substrate 101, form the hole 121 of the prescribed depth D corresponding with the pattern form of resist 102.
At this, if with the opening diameter L on the top in hole 121
5Diameter L with the bottom
6Compare, then Di Bu diameter L
6Smaller, be appreciated that thus the sidewall slope ground in hole 121 forms.That is, to form cross sectional view be taper in hole 121.The sidewall and the horizontal direction angulation (180 °-θ below are designated as " Sidewall angles ") in preferred hole 121 form for example 83 °～87 °.
Like this, use shower nozzle 20 to have annular convex 40 and gas squit hole 22 is concentrated near the central portion of the following 20b that is arranged on shower nozzle 20 plasma-etching apparatus 100, with resist 102 as mask, carry out the etching of silicon substrate 101, thus, can realize the uniformity of etch-rate in the face of wafer W and the control and the homogenizing in the face of wafer W of etching shape.Thereby, can make the degree of depth unanimity in the hole in the face of wafer W, while can be controlled to the hole that the Sidewall angles of regulation forms uniform shape.
Then, enumerate test example, embodiment and comparative example, the present invention is described in further detail, but the present invention is not subjected to their restriction.In addition, in following test example etc., used the wafer W of 8 inch diameters (200mm diameters).
Test example 1
Use the shower nozzle 20 of the annular convex 40 that is provided with A, two kinds of sizes of B shown in following, interelectrode distance (clearance G) up and down is set at 22mm, 27mm or 32mm, to implementing plasma etch process with the handled object 110 of spline structure, on silicon substrate 101, form hole 121 with Fig. 6.In addition, as shower nozzle 20, use the shower nozzle that pellumina is handled has been carried out on the surface.
Annular convex A:
Overhang (H)=15mm
External diameter (L
1)=260mm
Internal diameter (L
2)=240mm
Width [(L
1-L
2) * 1/2]=10mm
Annular convex B:
Overhang (H)=21mm
External diameter (L
1)=270mm
Internal diameter (L
2)=240mm
Width [(L
1-L
2) * 1/2]=15mm
Etching condition is as described below.
Resist: thickness=7 μ m
Handle gas: SF
6/ O
2=170/50mL/min (sccm)
Pressure=37.3Pa (280mTorr)
RF frequency (high frequency electric source 15)=40MHz
RF power=840W (2.68W/cm
2)
Magnetic field=17000 μ T (170G)
Back pressure (central part/edge part)=1333/4000Pa (10/30Torr, He gas)
Temperature (lower electrode/upper electrode/chamber sidewall)=0 ℃/40 ℃/40 ℃
Etching period=4 minutes 11 seconds
The cross sectional shape (etching shape) in the hole 121 that forms for the plasma etching that utilizes above-mentioned condition has been estimated its uniformity in the face of wafer W.Its result is illustrated in the table 1.In table, zero symbolic representation is controlled to be the controlled good of taper with the etching shape, and * symbolic representation is controlled bad.
Table 1
| Annular convex | Gap (mm) | ||
| 22 | 27 | 32 | |
| A | × | - | - |
| B | - | ○ | - |
| B | - | - | ○ |
As shown in Table 1, using under the situation of overhang (H) as the annular convex A of the weak point of 15mm, even when the shortest 22mm of clearance G, can not obtain the controlled of etching shape.Therefore think,, need to surpass the overhang H of minimum 15mm in order to obtain the controlled of good etching shape.
Test example 2
Then, as shower nozzle 20, use the shower nozzle that possesses 49 gas squit holes 22 in the region S of the 108.7mm * 108.7mm of the middle body of 20b in its lower section, distance between upper/lower electrode (clearance G) is set at 22mm, 27mm, 32mm or 33mm, with the same condition of test example 1 under, to implementing plasma etch process with the handled object 110 of spline structure, on silicon substrate 101, form hole 121 with Fig. 6.Then, for the etch depth D in hole 121, estimated its uniformity in the face of wafer W.Its result is illustrated in the table 2.In table, have good uniformity in the wafer face of zero symbolic representation etch depth, the wafer inner evenness of * symbolic representation etch depth is bad.
Table 2
| Annular convex | Gap (mm) | ||
| 27 | 32 | 33 | |
| A | ○ | - | - |
| B | ○ | - | - |
| B | - | ○ | - |
| B | - | - | × |
As shown in Table 2, in the region S of 108.7mm * 108.7mm, possess in the shower nozzle 20 of 49 gas squit holes 22, annular convex A and annular convex B are in clearance G is the scope of 27mm～32mm, can both in wafer face, obtain uniform etch depth, but, when clearance G is 33mm,, can not obtain the uniformity of etch depth in wafer face even use the annular convex B of overhang H as 21mm.Can infer from this result, in order to obtain the wafer inner evenness of etch depth, need be according to selecting the projecting height H of annular convex 40 with the relation of clearance G.
Test example 3
Then, use is formed with Y from the teeth outwards
2O
3The shower nozzle 20 of sputtered films of bismuth, the number of the gas squit hole 22 that makes the area of the region S that the gas squit hole of the central portion of 20b below it distributes, forms with side within it is by changing shown in the table 3, with the same condition of test example 1 under, to implementing plasma etch process with the handled object 110 of spline structure, on silicon substrate 101, form hole 121 with Fig. 6.Then, for the etch depth in hole 121, estimated its uniformity in the face of wafer W.In addition, in this test, interelectrode distance (clearance G) up and down is set at 37mm, annular convex 40 is not set.Its result is illustrated in the table 3 together.In table, have good uniformity in the wafer face of zero symbolic representation etch depth, the wafer inner evenness of * symbolic representation etch depth is bad.
Table 3
| Gas squit hole number | The area of squit hole distributed areas S | ||
| 61.7mm × 61.7mm | 96.96mm × 96.96mm | 120.5mm × 120.5mm | |
| 25 | ○ | - | - |
| 37 | - | ○ | - |
| 81 | - | - | × |
According to table 3, wafer W with respect to the 200mm diameter, the shower nozzle 20 that in the region S of 61.7mm * 61.7mm, is formed with the shower nozzle 20 of 25 gas squit holes 22 and in the region S of 96.96mm * 96.96mm, is formed with 37 gas squit holes 22, can in wafer face, obtain uniform etch depth, relative therewith, the shower nozzle 20 that has 81 gas squit holes 22 in the region S of 120.5mm * 120.5mm can not obtain the wafer inner evenness of etch depth.Can think from this result,, need to select the configuration and the number of gas squit hole 22 in order to obtain the wafer inner evenness of etch depth.
According to above-mentioned result of the test, implement following comparative example 1～3 and embodiment 1.
Comparative example 1
Use annular convex 40 be not set, in the region S of 210mm * 210mm, be equipped with the shower nozzle of the existing structure of 153 gas squit holes 22, under the following conditions, to implementing plasma etch process with the handled object 110 of spline structure, on silicon substrate 101, form hole 121 with Fig. 6.
Etching condition is as described below.
Resist: thickness=7 μ m
Handle gas: SF
6/ O
2=170/50mL/min (sccm)
Pressure=37.3Pa (280mTorr)
RF frequency (high frequency electric source 15)=40MHz
RF power=840W (2.68W/cm
2)
Magnetic field=17000 μ T (170G)
Gap=37mm
Back pressure (central part/edge part)=1333/4000Pa (10/30Torr, He gas)
Temperature (lower electrode/upper electrode/chamber sidewall)=0 ℃/40 ℃/40 ℃
Etching period=4 minutes 11 seconds
Comparative example 2
Use comprises overhang (H)=21mm, external diameter (L
1)=270mm, internal diameter (L
2)=240mm, width [(L
1-L
2) * 1/2]=annular convex 40 of the shape of 15mm, and in the region S of 210mm * 210mm, be equipped with the shower plate (shower plate) of 153 gas squit holes 22, under the following conditions, to implementing plasma etch process with the handled object 110 of spline structure, on silicon substrate 101, form hole 121 with Fig. 6.
Etching condition is as described below.
Resist: thickness=7 μ m
Handle gas: SF
6/ O
2=170/50mL/min (sccm)
Pressure=37.3Pa (280mTorr)
RF frequency (high frequency electric source 15)=40MHz
RF power=700W (2.23W/cm
2)
Magnetic field=17000 μ T (170G)
Gap=37mm
Back pressure (central part/edge part)=1333/4000Pa (10/30Torr, He gas)
Temperature (lower electrode/upper electrode/chamber sidewall)=0 ℃/40 ℃/40 ℃
Etching period=4 minutes 11 seconds
Comparative example 3
Use centralized configuration in the region S of 61.7mm * 61.7mm that annular convex 40, the central portion below shower plate are not set that the shower plate of 25 gas squit holes 22 is arranged, under the following conditions, to implementing plasma etch process with the handled object 110 of spline structure, on silicon substrate 101, form hole 121 with Fig. 6.
Etching condition is as described below.
Resist: thickness=7 μ m
Handle gas: SF
6/ O
2=170/50mL/min (sccm)
Pressure=37.3Pa (280mTorr)
RF frequency (high frequency electric source 15)=40MHz
RF power=840W (2.68W/cm
2)
Magnetic field=17000 μ T (170G)
Gap=37mm
Back pressure (central part/edge part)=1333/4000Pa (10/30Torr, He gas)
Temperature (lower electrode/upper electrode/chamber sidewall)=0 ℃/40 ℃/40 ℃
Etching period=4 minutes 11 seconds
Use comprises overhang (H)=21mm, external diameter (L
1)=270mm, internal diameter (L
2)=240mm, width [(L
1-L
2) * 1/2]=annular convex 40 of the shape of 15mm, and concentrate the shower plate that is equipped with 49 gas squit holes 22 in the region S of the 108.7mm * 108.7mm of the central portion below shower plate, under the following conditions, to implementing plasma etch process with the handled object 110 of spline structure, on silicon substrate 101, form hole 121 with Fig. 6.
Etching condition is as described below.
Resist: thickness=7 μ m
Handle gas: SF
6/ O
2=170/50mL/min (sccm)
Pressure=33.3Pa (250mTorr)
RF frequency (high frequency electric source 15)=40MHz
RF power=500W (1.59W/cm
2)
Magnetic field=17000 μ T (170G)
Gap=32mm
Back pressure (central part/edge part)=1333/4000Pa (10/30Torr, He gas)
Temperature (lower electrode/upper electrode/chamber sidewall)=0 ℃/40 ℃/40 ℃
Etching period=4 minutes 30 seconds
After the plasma etching of above-mentioned comparative example 1～3, embodiment 1, a plurality of points in the face of each wafer W, according to the photo of transmission electron microscope, the etch depth of measured hole 121 and etching shape (Sidewall angles).Measuring point is the interior central authorities of face (center), edge 50mm, edge 30mm, edge 20mm and the edge 10mm of wafer W.At this, " edge 50mm " is meant the position that enters 50mm from all ends central authorities in face of wafer.Equally, " edge 30mm ", " edge 20mm " and " edge 10mm " are meant the position that enters 30mm, 20mm and 10mm from all ends central authorities in face of wafer respectively.The result of comparative example 1～3, embodiment 1 is gathered and be illustrated in the table 4.
| The center | Edge 50mm | Edge 30mm | Edge 20mm | Edge 10mm | Uniformity (%) | ||
| Comparative example 1 | Etch depth (μ m) | 111.0 | 101.9 | - | - | 88.7 | 11.1 |
| Sidewall angles (°) | 87.9 | 89.0 | - | - | 89.1 | 0.7 | |
| Comparative example 2 | Etch depth (μ m) | 129.0 | 121.3 | 116.0 | 110.0 | 112.7 | 8.1 |
| Sidewall angles (°) | 85.5 | 85.7 | - | - | 86.4 | 0.6 | |
| Comparative example 3 | Etch depth (μ m) | 90.0 | 91.8 | 89.2 | 86.4 | 82.8 | 5.1 |
| Sidewall angles (°) | 88.3 | 88.6 | - | - | 90.0 | 1.0 | |
| | Etch depth (μ m) | 105.0 | 111.3 | 108.2 | 105.5 | 105.0 | 3.0 |
| Sidewall angles (°) | 83.0 | 84.9 | - | - | 83.3 | 1.1 | |
As shown in table 4, in the plasma etching result of the comparative example 1 of the shower nozzle that uses the broad existing structure in formation zone that annular convex 40, gas squit hole 22 are not set, the fluctuation of the etch depth (degree of depth in hole 121) in the wafer face is big.In addition, especially at the edge part of wafer W, the Sidewall angles in hole 121 can not be controlled to be taper with cross sectional view near 90 °.
In formation zone that use is provided with annular convex 40, gas squit hole 22 with the plasma etching result of the comparative example 2 of the same broad shower nozzle of the shower nozzle of existing structure in, the Sidewall angles in hole 121 is compared with comparative example 1 and is improved, can make sidewall slope a little, but the fluctuation of etch depth (degree of depth in hole 121) in the wafer face is still very big.
In the plasma etching result of the comparative example 3 that uses shower nozzle annular convex 40 is not set, only straitly forms in the formation zone at gas squit hole 22, compare with comparative example 1,2, the fluctuation of the etch depth (degree of depth in hole 121) in the wafer face improves.But the Sidewall angles in hole 121 and comparative example 1 can not be controlled to be taper with cross sectional view equally near 90 °.
Being provided with annular convex 40 and the central portion below shower plate in use concentrates among the plasma etching result of embodiment 1 of the shower plate that is equipped with gas squit hole 22, compare with comparative example 1～3, the fluctuation of the etch depth (degree of depth in hole 121) in the wafer face is significantly improved.In addition, the Sidewall angles in hole 121 reaches 83 °～85 °, can in the entire wafer face cross sectional view be controlled to be taper.
From the contrast of comparative example 1 and comparative example 2 as can be known, thus for the sidewall slope that makes hole 121 is controlled to be taper with the etching cross section, the shower plate by use has annular convex 40 can access effect roughly.
In addition, from the contrast of comparative example 1 and comparative example 3 as can be known, concentrate the shower plate that is provided with gas squit hole 22, can see that the wafer inner evenness of etch depth roughly improves by using the central portion below shower plate.
But, from the contrast of comparative example 2,3 and embodiment 1 as can be known, be provided with annular convex 40 and concentrate among the embodiment 1 of the shower plate be equipped with gas squit hole 22 in use at central portion, the Sidewall angles in the wafer inner evenness of etch depth and hole 121 controlled two aspect, obviously than comparative example 1,2 excellences.That is, the result of embodiment 1 is not the result's of comparative example 1,2 a summation, and controlled two aspects of the wafer inner evenness of etch depth and etching shape all are enhanced excellently more.
More than, narrated embodiments of the present invention, but the present invention is not restricted to above-mentioned execution mode, can carry out various distortion.For example, in the above-described embodiment, the magnetic field formation device as magnetron RIE plasma-etching apparatus has used the dipole annular magnet, but has been not limited thereto, and the formation in magnetic field neither be necessary.In addition, as long as can utilize gas kind of the present invention to form plasma, device can use various plasma-etching apparatus such as capacitive coupling type, inductance coupling high type without limits.
Utilizability on the industry
The present invention can be suitable for utilizing in the process of the various semiconductor devices such as Production Example such as transistor.
Claims (10)
1. a plasma-etching apparatus is characterized in that, comprising:
Be used for handled object is carried out process chamber plasma etch process, can decompression exhaust;
The mounting table of mounting handled object in described process chamber;
The processing gas that disposes, will be used to generate plasma relatively with described mounting table imports the shower nozzle in the described process chamber;
Below described shower nozzle, to the outstanding in the form of a ring annular convex that is provided with of described mounting table; With
The inboard central portion of the described annular convex below described shower nozzle, distributing is provided in area than a plurality of gas squit holes in the little zone of the area of handled object.
2. plasma-etching apparatus according to claim 1 is characterized in that:
As lower electrode, as upper electrode, constitute a pair of comparative electrode with described mounting table with described shower nozzle.
3. plasma-etching apparatus according to claim 1 and 2 is characterized in that:
With respect to the diameter L of handled object, the external diameter of described annular convex is 1.1L～1.5L.
4. plasma-etching apparatus according to claim 3 is characterized in that:
The internal diameter of described annular convex is greater than the diameter L of handled object.
5. according to each described plasma-etching apparatus in the claim 1～4, it is characterized in that:
The height of described annular convex is more than 0.4 times of distance from described mounting table to described shower nozzle.
6. according to each described plasma-etching apparatus in the claim 1～5, it is characterized in that:
With respect to the diameter L of handled object, described gas squit hole forms in the zone of the area with 0.3L * 0.3L～0.7L * 0.7L.
7. plasma-etching method is characterized in that:
Use each described plasma-etching apparatus in the claim 1～6,
For having with silicon is the handled object of the etched layer of main component and the resist layer that is patterned in advance that forms on upper strata of this etched layer, and effect is by containing SF
6And O
2The plasma that generates of processing gas, be mask with described resist, etched layer is carried out plasma etch process.
8. plasma-etching method according to claim 7 is characterized in that:
Described etched layer is silicon substrate or silicon layer.
9. control program is characterized in that:
When moving on computers, control described plasma-etching apparatus, implement claim 7 or 8 described plasma-etching methods.
10. the storage medium of an embodied on computer readable stores the control program of operation on computers, it is characterized in that:
Described control program is controlled described plasma-etching apparatus when operation, implement claim 7 or 8 described plasma-etching methods.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006049639 | 2006-02-27 | ||
| JP2006049639A JP4827083B2 (en) | 2006-02-27 | 2006-02-27 | Plasma etching apparatus and plasma etching method |
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| Publication Number | Publication Date |
|---|---|
| CN101030538A true CN101030538A (en) | 2007-09-05 |
| CN100561679C CN100561679C (en) | 2009-11-18 |
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ID=38549305
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2007100858027A Expired - Fee Related CN100561679C (en) | 2006-02-27 | 2007-02-27 | Plasma-etching apparatus and plasma-etching method |
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|---|---|
| JP (1) | JP4827083B2 (en) |
| CN (1) | CN100561679C (en) |
Cited By (7)
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| CN102005381A (en) * | 2009-09-02 | 2011-04-06 | 东京毅力科创株式会社 | Plasma processing apparatus |
| CN102797012A (en) * | 2012-07-27 | 2012-11-28 | 京东方科技集团股份有限公司 | Etching equipment and upper part electrode thereof |
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| CN107546092A (en) * | 2016-06-28 | 2018-01-05 | 周业投资股份有限公司 | upper electrode device |
| CN108321101A (en) * | 2018-02-24 | 2018-07-24 | 惠科股份有限公司 | A kind of electrode assembly and etching machines |
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| JP2009188257A (en) | 2008-02-07 | 2009-08-20 | Tokyo Electron Ltd | Plasma etching method, plasma etching apparatus, and storage medium |
| JP2011124295A (en) * | 2009-12-09 | 2011-06-23 | Hitachi High-Technologies Corp | Plasma processing apparatus |
| JP5830275B2 (en) * | 2011-06-15 | 2015-12-09 | 東京エレクトロン株式会社 | Plasma etching method |
| JPWO2013183437A1 (en) * | 2012-06-08 | 2016-01-28 | 東京エレクトロン株式会社 | Gas processing method |
| US20170069497A1 (en) * | 2014-05-07 | 2017-03-09 | Tokyo Electron Limited | Plasma etching method |
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| JP3408994B2 (en) * | 1999-05-24 | 2003-05-19 | 株式会社日立製作所 | Plasma processing apparatus and control method for plasma processing apparatus |
| JP2004087738A (en) * | 2002-08-26 | 2004-03-18 | Tokyo Electron Ltd | Si etching method |
| JP2004247454A (en) * | 2003-02-13 | 2004-09-02 | Disco Abrasive Syst Ltd | Plasma etching device |
-
2006
- 2006-02-27 JP JP2006049639A patent/JP4827083B2/en not_active Expired - Fee Related
-
2007
- 2007-02-27 CN CNB2007100858027A patent/CN100561679C/en not_active Expired - Fee Related
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102005381A (en) * | 2009-09-02 | 2011-04-06 | 东京毅力科创株式会社 | Plasma processing apparatus |
| CN102005381B (en) * | 2009-09-02 | 2012-12-12 | 东京毅力科创株式会社 | Plasma processing apparatus |
| CN102797012A (en) * | 2012-07-27 | 2012-11-28 | 京东方科技集团股份有限公司 | Etching equipment and upper part electrode thereof |
| WO2014015567A1 (en) * | 2012-07-27 | 2014-01-30 | 京东方科技集团股份有限公司 | Etching device and upper electrode thereof |
| CN107546092A (en) * | 2016-06-28 | 2018-01-05 | 周业投资股份有限公司 | upper electrode device |
| CN107516625A (en) * | 2017-07-13 | 2017-12-26 | 江苏鲁汶仪器有限公司 | A kind of spray head of plasma etching system |
| CN107393802A (en) * | 2017-07-17 | 2017-11-24 | 江苏鲁汶仪器有限公司 | A kind of spray head of plasma etching system |
| CN108321101A (en) * | 2018-02-24 | 2018-07-24 | 惠科股份有限公司 | A kind of electrode assembly and etching machines |
| CN108321101B (en) * | 2018-02-24 | 2020-09-11 | 惠科股份有限公司 | Electrode assembly and etching equipment |
| CN110867365A (en) * | 2019-11-04 | 2020-03-06 | 北京北方华创微电子装备有限公司 | Plasma system |
| CN110867365B (en) * | 2019-11-04 | 2022-05-27 | 北京北方华创微电子装备有限公司 | Plasma system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2007227829A (en) | 2007-09-06 |
| JP4827083B2 (en) | 2011-11-30 |
| CN100561679C (en) | 2009-11-18 |
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