Case 6:20-cv-00636-ADA Document 89 Filed 03/30/21 Page 1 of 5
`Case 6:20-cv-00636—ADA Document 89 Filed 03/30/21 Page 1 of 5
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`EXHIBIT AC
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`EXHIBIT AC
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`Case 6:20-cv-00636-ADA Document 89 Filed 03/30/21 Page 2 of 5
`A PVD Productivity and Technology Publication I Oct. 1996 Vol. 3, No. 3
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`Case 6:20-cv-00636-ADA Document 89 Filed 03/30/21 Page 3 of 5
`A REVOLUTION IN METALLIZATION
`
`A New Source for
`Sub-Half Micron
`Barrier and Liner
`
`\Iectra
`1114.P Deposition
`Source John Forster, Member
`
`of the Technical Staff
`
`Applied Materials has developed a new
`
`techniques,
`
`it
`
`is necessary to physically
`
`source for deposition of Ti and TiN films
`
`filter the flux of sputtered metal atoms.
`
`in sub-half micron features, the Vectra
`IMP source. It relies on a new metal
`lization technology, Ion Metal Plasma
`
`This is usually done by inserting a
`collimator between the target and
`
`substrate, or by increasing the target-to-
`
`(IMP), to overcome traditional limita
`
`wafer spacing (long throw). The dis
`
`tions of PVD sources. Exceptional results
`
`advantage of collimation is that physical
`
`are possible with this ne’v technology.
`
`filtering of the flux dramatically reduces
`
`Up to 70% bottom coverage is achieved
`
`its volume. The largest practical aspect
`
`on sub-quarter micron structures with
`
`aspect ratios as great as 8:1 (cover photo).
`
`ratio for physical filtering is about 2:1.
`At larger aspect ratios, the deposition
`
`Because the bottom coverage is so high,
`
`rate becomes unacceptably low and
`
`thinner deposited barrier or liner layers
`achieve the same or better device results
`
`compared to thicker films deposited by
`
`preventive maintenance (PM) increases.
`
`Physical filtering is not likely to be
`acceptable for vias or contacts below C.35
`
`collimation or long throw techniques.
`
`urn (Fig. 1).
`
`And the Vectra IMP source achievcs
`
`exceptional bottom coverage without the
`
`high cost associated with collimated or
`
`long throw PVD.
`
`Deposition Dynamics
`
`In PVD, step coverage is governed by the
`
`angular distribution of material arriving
`
`at the wafer surface. A “tighter” angular
`
`distribution (more material arriving at
`
`near normal incidence) leads to better
`
`bottom coverage. To alter the angular
`
`distribution using traditional PVD
`
`2
`
`U1’t)ATE
`
`Excellent Bottom Coverage Achieved
`
`The angular distribution of material
`
`arriving at the substrate can be controlled
`
`to achieve maximized bottom deposition
`
`if the metal is ionized. Using the Vectra
`
`IMP source, a medium density plasma
`(loll cm3 < n < 10(2 cm-3) is created
`between the target and substrate. Sput
`
`tered metal atoms passing through this
`
`region become ionized. A high electric
`
`field, or self bias, develops in the boun
`
`dary layer separating the plasma from the
`
`substrate (the sheath). This self bias
`
`accelerates the metal ions in a vector
`
`normal to the substrate. The plasma is
`
`maintained by inductively coupling
`
`energy from an RF generator into the
`
`plasma (Fig. 2). The self bias that devel
`
`ops between the plasma and the substrate
`
`can be optionally modulated by apply
`
`ing independent AC bias power to
`
`the substrate.
`
`The probability of sputtered metal
`
`atoms ionizing depends on their resi
`
`Fig. 1: IMP
`Ti/TiN exhibits
`superior
`bottom
`coverage with
`less field
`deposition
`compared to
`collimated
`PVD
`
`Top Thickness: 1150A
`Bottom Thickness: ZOBA
`Bottom Coverage: 16%
`
`Top Thickness: 7BDA
`Bottom Thickness: 540A
`Bottom Coverage: 69%
`
`

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`Case 6:20-cv-00636-ADA Document 89 Filed 03/30/21 Page 4 of 5
`
`be used even for sub 0.1 urn contacts
`
`(Fig. 4).
`
`Device Performance Verification
`
`A number of device performance studies
`have been completed that compare the
`barrier/liner performance of IMP Ti and
`
`TiN films with collimated films. In one
`study, W plug chains were deposited
`with 2CCA Ti/SODA TiN by conventional
`PVD and with varying thickness layers
`of IMP Ti/TiN to as thin as 50A/ICDA.
`The plugs deposited with IMP films
`show lower average contact resistance
`and a tighter distribution than the plugs
`with conventional PVD (Figs. 5 and 6).
`IMP films exhibit more tightly dis
`tributed performance compared to
`conventional barriers, even as film
`
`thickness decreases, because the high
`bottom coverage typical 0f IMP films
`ensures that a sufficient amount of
`material is deposited into the bottom of
`the hole, reducing the requirement for
`
`—
`
`Target
`
`DC9
`
`PIssma
`
`wa’er
`
`Fig. 2: Schematic of the Vectra IMP
`Source
`
`dence time in the plasma. Longer resi
`dence times lead to a higher ionization
`probability. Sputtered atoms are ejected
`from the target with relatively high
`to 10eV). These fast atoms
`energies (‘— 1
`have very short residence tirnes. Opera
`ting the source at relatively high pressure
`slows down the metal atoms because the
`number of collisions between the sput
`tered metal atoms and the background
`gas increases. Longer residence time
`increases the prohabihtv of metal atom
`
`I
`
`60—
`
`55—
`
`50 —
`45
`0.4
`
`AR
`I
`0.35
`
`5:1
`I
`0.3
`
`7,5:1
`I
`0.2
`
`I
`0,25
`
`0.15
`
`12:1
`I
`0.1
`
`0.05 0.01
`
`contact Diameter (pml
`
`Fig. 4: Bottom step coverage for IMP TiN
`as function of contact diameter and
`aspect ratio (AR) for contacts of Fig. 3.
`IMP technology can be extrapolated to
`sub-0.1 pm applications
`
`ionization. Excellent bottom coverage
`results are obtained only if the Vectra
`IMP source is run at pressures greater
`than 10 mTorr—pressures much greater
`than normally encountered in tradi
`
`tional PVD.
`‘With Vectra IMP technologs-. the
`bottom coverage characteristic of the
`film is not substantially atfected by
`contact width, making the process highly
`scalable to different device geometries
`(Fig. 3). Extrapolating the bottom cover
`age performance shown in Figure 3
`indicates that Vectra IMP technology can
`
`-
`
`Con:roi
`
`—VectaIVP——.
`
`1.5 —
`
`Ti Thk IAI
`TiNThkIAI
`
`200
`800
`
`50
`100
`
`200
`50
`800
`200
`*NormaIized Data
`
`3
`
`0.4cm contacts 1//10
`
`1
`
`—
`
`2
`
`0 1 —
`
`0.0
`
`Contra] 200A Ti/SCOA TiN
`2 IMP 100ATI/200ATiN
`2 IMP 5OAT1/200A1’iN
`IMP bOA Ti/600A TIN
`
`I
`2.0
`
`I
`4.0
`
`I
`6.0
`
`I
`8.0
`
`10.0
`
`Normalized Contact Resistance
`
`Fig. 3: Contact width does not substan
`tially affect the amount of material
`deposited at the bottom of the contact,
`making IMP technology highly scalable
`for different device geometries
`
`Fig. 5: IMP Ti and TiN barrier/line, films
`exhibit tightly distributed, low contact
`resistance, even for extremely thin films
`in a comparison performed on W plugs
`
`Fig. 6; Contact resistance of various
`thickness Vectra IMP TI/TiN liners is
`compared with conventional PVD TiITiN
`for a W plug application
`
`UPDATE
`
`3
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`

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`Case 6:20-cv-00636-ADA Document 89 Filed 03/30/21 Page 5 of 5
`
`Resistivity Behavior of
`Ti/A1CuSi Films
`
`Hougong Wang, PVD Account
`Technologist, and Steve Lai, PVD
`Regional Technology Manager,
`Asia-Pa cific
`
`Titanium is applied as a wetting layer for
`
`aluminum alloy interconnects in advanced
`
`integrated circuits. Formation of TiAl3 at
`
`the Ti/Al interface during high tempera
`
`ture processing influences circuit per
`
`formance. In this study, sheet resistance
`
`was characterized for both Ti/Al
`
`Fig. 7: The Vectra IMP source is designed
`for compatibility with widebody PVD
`chambers
`
`thick overall films. Device and TEM
`
`0.5%Cu and Ti/Al-0.5%Cu-1.0%5i
`
`results confirm that film coverage is
`
`bilayer films at 440°C and 480°C. The
`
`continuous and conformal even though
`
`change in resistivity due to TiAl3 growth
`
`sidewall coverage can be as ‘ow as 10%.
`
`was further studied for the Ti/Al
`
`The combination of highly efficient film
`
`0.5%Cu-1.0%Si bilayer film at 480°C.
`
`performance and extremely simple, easily
`
`The rate of TiAl3 formation depends
`
`maintained hardware make Vectra IMP
`
`on annealing temperature, time and alloy
`
`barrier and liner films extremely cost
`
`content of Cu and Si
`
`in the ,kl matrix.
`
`effective compared to other available
`
`Both Cu and Si retard TiAI3 formation,
`
`technologies.
`
`but Si exhibits a stronger effect than
`
`The Vectra IMP chamber will be
`released under the Applied Materials
`
`Cu.”2 The addition of Si increases the
`
`activation energy and reduces the Ti/Al
`
`of 440°C or 480°C. A sheet resistivity
`
`versus annealing time plot was generated
`
`for each wafer.
`
`Secondary ion mass spectrometry
`
`(SIMS) analysis was performed on the
`
`samples to determine Si and Cu distribu
`
`tion as a function of film depth. An
`
`oxygen ion beam with an incident angle
`
`of 60° was used on both rotating and
`
`stationary samples. X-ray diffraction
`
`(XRD) analysis was used to determine
`
`the phase content and grain size of the
`
`films. XRD was performed on the wafers
`
`in normal incidence mode (0/20) and
`glancing incidence mode ( = 0.5°).
`Transmission electron microscopy (TEM)
`
`equipped with energy dispersion spec
`
`trometry (EDS) was used to examine the
`
`interface microstructure and chemical
`
`composition. TEM cross sections were
`
`prepared by gluing pairs of samples face-
`
`to-face and then mechanically polishing
`
`the samples to electron transparency. Ion
`milling was used for a short duration to
`clean the sample surfaces.
`
`PDP (Product Development Process).1
`
`reaction rate significantly.3’4 At 430°C,
`
`Results and Discussion
`
`Under the PDP, the Vectra Source will be
`
`Al-Ti interdiffusivity is reduced by an
`
`The sheet resistivity of Ti/AICu bilayer
`
`8 :
`
`H1z111rj0F
`
`-6-
`
`-2
`
`—
`
`-
`
`r r
`
`Fig. 1: Sheet resistance behavior of AICu
`and AICuSi films deposited on Ti after 2
`minutes of annealing time at 440”C and
`480©C
`
`thoroughly performance evaluated as a
`
`order of magnitude with the addition of
`
`source for Ti, TiN and Ti/TiN films. The
`
`1.0%Si in the Al-0.5%Cu matrix.2
`
`Vectra Source (Fig. 7) will be available to
`
`customers in the first calendar quarter of
`1997 both on new Endura® and Centura®
`PVD systems and as a field upgrade to
`
`widebody chambers.
`
`References
`
`1. “The Product Development Process,”
`Applied Materials HF PVD Update, Dec. 1995,
`Vol. 2, No.4, p. 2.
`
`Experimental
`
`Titanium films were deposited on
`150 mm Si02 wafers (3 kW, 4 mTorr,
`200°C). Al-0.5%Cu-1.0%Si and Al
`
`0.5%Cu films were then deposited on
`
`top of the Ti films (9kW, 2 mTorr, 175°C).
`
`After deposition, the wafers were
`
`annealed for different durations in an
`
`empty chamber at a heater temperature
`
`4 UPDATE
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