EP0703598A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electrode between sputtering target and workpiece
Assignee: Applied Materials Inc
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Filing: 1995-09-25
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Granted: —
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Expires: 2015-09-25
Abstract
Abstract A sputtering chamber (10) for depositing a film on a semiconductor substrate (12) by sputtering a target (14). A collimating electrode (40) between the target (14) and the substrate (12) is connected to a voltage source (50). The voltage can be used to sputter clean the collimator (40), to collimate the flux of target material by accelerating target material ions, or to control the amount of sputtering process gas ions incorporated in the deposited film. A second electrode between the first electrode and the substrate can be connected to a positive voltage to decelerate ions to reduce the risk of damage to the substrate.
Inventors
- 👤 Jaim Nulman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 00:04
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/34; H01J37/3411; H01J37/3438; H01J37/3402; H01J37/3405; H01J37/3408; H01J37/3447; H01J2237/00; H01J2237/32; H01J2237/33; H01J2237/332; H01J2237/3322; H01J2237/3327
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
129 words
Apparatus for deposition onto a semiconductor substrate of a collimated flux of material sputtered from a target, comprising: a sputtering chamber having an electrically grounded wall; a sputtering target within the chamber; a gas source for supplying a process gas into the chamber; a plasma source for exciting the gas into a plasma state in a region adjacent the target to promote sputtering of material from the target; a support member for holding the substrate within the chamber; a collimator electrode between the target and the substrate support; and a first voltage source connected to supply a first voltage between the collimator electrode and the grounded chamber wall; whereby the first voltage controls the amount of process gas atoms which are incorporated in the material deposited on the substrate.
Claim 2
Dependent Claim
71 words
Apparatus according to claim 1, further comprising: a second electrode between the collimator electrode and the substrate support, and a second voltage source connected to supply a voltage to the second electrode which is positive relative to the grounded chamber wall, whereby the positive voltage on the second electrode decelerates ions traveling from the direction of the collimator toward the substrate, reducing the risk of high energy ions damaging the substrate.
Claim 3
Dependent Claim
182 words
Apparatus for deposition onto a semiconductor substrate of a collimated flux of material sputtered from a target, comprising: a sputtering chamber having a wall connected to an electrical ground; a sputtering target within the chamber; a gas source for supplying a process gas into the chamber; a plasma source for exciting the gas into a plasma state in a region adjacent the target to promote sputtering of material from the target; a support member for holding the substrate within the chamber; a perforated collimator plate between the target and the substrate support, the collimator plate being perforated with one or more apertures, each aperture having a length and width such that the ratio of length to width is great enough to obstruct the passage through the collimator of target material having a trajectory deviating by more than a predetermined angle from a perpendicular to the substrate; and a first voltage source connected to supply a first voltage to the collimator plate; whereby the first voltage controls the proportion of process gas atoms which are incorporated in the material deposited on the substrate.
Claim 4
Dependent Claim
39 words
Apparatus according to claim 3, wherein the first voltage is negative with respect to said electrical ground during some periods of time, whereby ions in the plasma are attracted to the collimator plate to sputter clean the collimator plate.
Claim 5
Dependent Claim
71 words
Apparatus according to claim 4, further comprising: a second electrode between the collimator electrode and the substrate support, and a second voltage source connected to supply a voltage to the second electrode which is positive relative to the grounded chamber wall, whereby the positive voltage on the second electrode decelerates ions traveling from the direction of the collimator toward the substrate, reducing the risk of high energy ions damaging the substrate.
Claim 6
Dependent Claim
22 words
Apparatus according to claim 4, wherein the collimator has at least an outer portion composed of the same material as the target.
Claim 7
Dependent Claim
15 words
Apparatus according to claim 4, wherein the first voltage source supplies a negative D.C. voltage.
Claim 8
Dependent Claim
27 words
Apparatus according to claim 4, wherein the first voltage source supplies an A.C. voltage having a periodic waveform which is negative during a portion of its cycle.
Claim 9
Dependent Claim
21 words
Apparatus according to claim 4, wherein the first voltage source supplies an A.C. voltage superimposed with a negative D.C. offset voltage.
Claim 10
Dependent Claim
44 words
Apparatus according to claim 4, wherein the first voltage source includes: an A.C. voltage supply, and a capacitor connected between the A.C. voltage supply and the collimator, whereby a D.C. voltage develops across the capacitor to impose a negative D.C. bias on the collimator.
Claim 11
Dependent Claim
178 words
Apparatus for deposition onto a semiconductor substrate of a collimated flux of material sputtered from a target, comprising: a sputtering chamber having a wall connected to an electrical ground; a sputtering target within the chamber; a gas source for supplying a process gas into the chamber; a plasma source for exciting the gas into a plasma state in a region adjacent the target to promote sputtering of material from the target; a support member for holding the substrate within the chamber; a porous grid electrode between the target and the substrate support; an ionizing power source for supplying energy to ionize at least a portion of the sputtered target material in a region between the target and the grid; and a first voltage source connected to supply to the electrode a first voltage which is negative with respect to said electrical ground at least a portion of the time; whereby, during periods when the first voltage is negative, ionized target material is acclerated toward the grid, thereby collimating the flux of target material being deposited on the substrate.
Claim 12
Dependent Claim
71 words
Apparatus according to claim 11, further comprising: a second electrode between the collimator electrode and the substrate support, and a second voltage source connected to supply a voltage to the second electrode which is positive relative to the grounded chamber wall, whereby the positive voltage on the second electrode decelerates ions traveling from the direction of the collimator toward the substrate, reducing the risk of high energy ions damaging the substrate.
Claim 13
Dependent Claim
15 words
Apparatus according to claim 11, wherein the first voltage source supplies a negative D.C. voltage.
Claim 14
Dependent Claim
27 words
Apparatus according to claim 11, wherein the first voltage source supplies an A.C. voltage having a periodic waveform which is negative during a portion of its cycle.
Claim 15
Dependent Claim
21 words
Apparatus according to claim 11, wherein the first voltage source supplies an A.C. voltage superimposed with a negative D.C. offset voltage.
Claim 16
Dependent Claim
46 words
Apparatus according to claim 11, wherein the first voltage source includes: an A.C. voltage supply, and a capacitor connected between the A.C. voltage supply and the grid electrode, whereby a D.C. voltage develops across the capacitor to impose a negative D.C. bias on the grid electrode.
Claim 17
Independent Claim
149 words
A method of controlling the incorporation of a sputtering gas in a film layer deposited on a substrate, comprising: providing a grounded enclosure having at least a sputtering target and a substrate support therein; providing a sputtering gas into the enclosure and exiting the gas into a plasma; sputtering the target with the plasma to provide a flux of target material to form a film layer on the substrate; placing a a porous electrode intermediate the substrate and the target; applying a negative voltage to the porous electrode to attract ions of the sputtering gas in the direction of, and through, the porous electrode to deposit on the substrate; and varying the magnitude of the negative voltage applied to the porous electrode and thereby changing the quantity of sputtering gas incorporated in the film deposited on the substrate relative to the quantity of target material deposited on the substrate.
Claim 18
Dependent Claim
48 words
The method of claim 17, including the further step of: varying the partial pressure of the sputtering gas in the enclosure and thereby changing the quantity of sputtering gas incorporated in the film deposited on the substrate relative to the quantity of target material deposited on the substrate.
Claim 19
Independent Claim
147 words
A method of controlling the incorporation of a sputtering gas in a film layer deposited on a subst:rate, comprising: providing a grounded enclosure having at least a sputtering target and a substrate support therein; providing a sputtering gas into the enclosure and exiting the gas into a plasma; sputtering the target with the plasma to provide a flux of target material to form a film layer on the substrate; placing a porous electrode intermediate the substrate and the target; applying a negative voltage to the porous electrode to attract ions of the sputtering gas in the direction of, and through, the porous electrode to deposit on the substrate; and varying the partial pressure of the sputtering gas in the enclosure and thereby changing the quantity of sputtering gas incorporated in the film deposited on the substrate relative to the quantity of target material deposited on the substrate.
Claim 20
Dependent Claim
49 words
The method of claim 19, including the further step of: varying the magnitude of the negative voltage applied to the porous electrode and thereby changing the quantity of sputtering gas incorporated in the film deposited on the substrate relative to the quantity of target material deposited on the substrate.
Claim 21
Independent Claim
65 words
A method of preparing a plate collimator for use in a sputtering chamber wherein the plate collimator may be sputter cleaned during use, comprising: providing a sputtering chamber having an enclosure and a target therein; locating a plate collimator adjacent the target; and sputtering the target while connecting the collimator to electrical ground, so as to deposit a layer of target material on the collimator.
Claim 22
Dependent Claim
81 words
The method of claim 21, further including the steps of: positioning a substrate support member in the sputtering chamber such that the collimator is disposed between the substrate support member and the target; sputtering the target to provide a flux of target material for deposition on the substrate; passing the flux of target material through the collimator and thereby collimating the flux of target material reaching the substrate; and maintaining a negative voltage on the collimator to sputter clean the collimator.
Claim 23
Dependent Claim
32 words
The method of claim 22, including the further step of maintaining the negative voltage on the collimator during at least a portion of the duration of the step of sputtering the target.
Claim 24
Independent Claim
107 words
A method of depositing onto a semiconductor substrate a collimated flux of material sputtered from a target, comprising: supporting a semiconductor wafer within a sputtering chamber having a sputtering target and an electrically grounded wall; supplying a process gas into the chamber; exciting the gas into a plasma state in a region adjacent the target to sputter material from the target; providing a collimator electrode between the target and the substrate support; and supplying a first voltage between the collimator electrode and the grounded chamber wall; whereby the first voltage controls the proportion of process gas atoms which are incorporated in the material deposited on the substrate.
Claim 25
Dependent Claim
36 words
A method according to claim 24, further comprising the step of adjusting the first voltage so as to deposit onto the substrate a film of target material which contains a desired proportion of process gas atoms.
Claim 26
Dependent Claim
66 words
A method according to claim 24, further comprising: providing a second electrode between the collimator electrode and the substrate, and supplying to the second electrode a voltage which is positive relative to the grounded chamber wall, whereby the positive voltage on the second electrode decelerates ions traveling from the direction of the collimator toward the substrate, reducing the risk of high energy ions damaging the substrate.
Claim 27
Independent Claim
162 words
A method for depositing onto a semiconductor substrate a collimated flux of material sputtered from a target, comprising: supporting a semiconductor wafer within a sputtering chamber having a sputtering target and an electrically grounded wall; supplying a process gas into the chamber; exciting the gas into a plasma state in a region adjacent the target to sputter material from the target; providing a perforated collimator plate between the target and the substrate support, the collimator plate being perforated with one or more apertures, each aperture having a length and width such that the ratio of length to width is great enough to obstruct the passage through the collimator of target material having a trajectory deviating by more than a predetermined angle from a perpendicular to the substrate; and supplying a first voltage between the collimator plate and the grounded chamber wall; whereby the first voltage controls the proportion of process gas atoms which are incorporated in the material deposited on the substrate.
Claim 28
Dependent Claim
40 words
A method according to claim 27, wherein the first voltage is negative with respect to said electrical ground during some periods of time, whereby ions in the plasma are attracted to the collimator plate to sputter clean the collimator plate.
Claim 29
Dependent Claim
66 words
A method according to claim 28, further comprising: providing a second electrode between the collimator electrode and the substrate, and supplying to the second electrode a voltage which is positive relative to the grounded chamber wall, whereby the positive voltage on the second electrode decelerates ions traveling from the direction of the collimator toward the substrate, reducing the risk of high energy ions damaging the substrate.
Claim 30
Independent Claim
155 words
A method of depositing onto a semiconductor substrate a collimated flux of material sputtered from a target, comprising: supporting a semiconductor wafer within a sputtering chamber having a sputtering target and an electrically grounded wall; supplying a process gas into the chamber; exciting the gas into a plasma state in a region adjacent the target to sputter material from the target; providing a porous grid electrode between the target and the substrate support; and supplying energy to ionize at least a portion of the sputtered target material in a region between the target and the grid; and supplying a first voltage between the collimator electrode and the grounded chamber wall which is negative with respect to said electrical ground at least a portion of the time; whereby, during periods when the first voltage is negative, ionized target material is acclerated toward the grid, thereby collimating the flux of target material being deposited on the substrate.
Claim 31
Dependent Claim
66 words
A method according to claim 30, further comprising: providing a second electrode between the collimator electrode and the substrate, and supplying to the second electrode a voltage which is positive relative to the grounded chamber wall, whereby the positive voltage on the second electrode decelerates ions traveling from the direction of the collimator toward the substrate, reducing the risk of high energy ions damaging the substrate.
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