WO2019005144A1

WO2019005144A1 - High throughput molecular beam epitaxy and apparatus for selective epitaxy

Info

Publication number: WO2019005144A1
Application number: PCT/US2017/040470
Authority: WO
Inventors: Sasikanth Manipatruni; John J. Plombon; Shakuntala SUNDARARAJAN; Chai-Ching Lin; Jasmeet S. Chawla; Ian Young
Original assignee: Intel Corporation
Priority date: 2017-06-30
Filing date: 2017-06-30
Publication date: 2019-01-03

Abstract

An apparatus is provided which comprises: a chamber for molecular beam epitaxy (MBE); an effusion source at least partially embedded in the chamber; a handle in the chamber to hold a substrate; and a signal source to provide a bias to the substrate, wherein the bias is to influence a trajectory of a material from the effusion source to the substrate.

Description

HIGH THROUGHPUT MOLECULAR BEAM EPITAXY AND APPARATUS FOR

SELECTIVE EPITAXY

BACKGROUND

[0001] Molecular beam epitaxy (MBE) is an epitaxy mechanism for depositing thin- film of single crystals. MBE is a method for making crystals. Other types of epitaxy mechanisms include MOVPE (metalorganic vapor phase epitaxy), OMVPE (organometallic vapor phase epitaxy), MOCVD (metal organic chemical vapor deposition), PVD (physical vapor deposition), and ALD (atomic layer deposition). Among these epitaxy mechanisms, PVD generally results in the lowest quality of crystallinity with the highest speed of deposition. Conversely, MBE creates excellent epitaxial and crystalline films, but with the lowest speed of deposition. The epitaxial and crystalline films from MBE are stabilized in metastable states via strain and lattice conditions. MBE also maintains the quantum mechanical nature of coupling across atomic interfaces. For example, exchange bias is maintained between atomic interfaces. However, existing MBE use is limited. For example, MBE is used to create wafers with super lattices for optical electronics and high electron mobility transistors. Currently, due to poor speed of deposition (among some reasons), MBE does not exist as a tool for an integrated chip manufacturing process.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The embodiments of the disclosure will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the disclosure, which, however, should not be taken to limit the disclosure to the specific embodiments, but are for explanation and understanding only.

[0003] Fig. 1 illustrates a high-level cross-section of a molecular beam epitaxy

(MBE) apparatus.

[0004] Figs. 2A-B illustrate drift assisted effusion sources of the MBE apparatus with different apertures, according to some embodiments of the disclosure.

[0005] Fig. 3 illustrates an MBE apparatus with drift enhanced deposition, according to some embodiments of the disclosure.

[0006] Fig. 4A illustrates an MBE apparatus with magnetic lensing and drift enhanced deposition, according to some embodiments of the disclosure.

[0007] Figs. 4B-C illustrate the operating principle of Lorentz field assist for MBE, according to some embodiments of the disclosure. [0008] Fig. 5 illustrates an MBE apparatus with an e-beam and drift enhanced deposition, according to some embodiments of the disclosure.

[0009] Fig. 6 illustrates part of the MBE apparatus with e-beam source and receiver, according to some embodiments of the disclosure.

[0010] Fig. 7 illustrates a perovskite lattice and possible material sources for use by the effusion sources, in accordance with some embodiments.

[0011] Figs. 8A-B illustrate a process of selective deposition of perovskites using the

MBE apparatus, according to some embodiments of the disclosure.

[0012] Fig. 9 illustrates an MBE apparatus with pulsed deposition of perovskites, according to some embodiments of the disclosure.

[0013] Fig. 10 illustrates a flowchart of a method of selective deposition of perovskites, according to some embodiments of the disclosure.

[0014] Fig. 11 illustrates a smart device or a computer system or a SoC (System-on-

Chip) having a substrate processed by the MBE apparatus, according to some embodiments of the disclosure.

DETAILED DESCRIPTION

[0015] Some embodiments describe a molecular beam epitaxy (MBE) apparatus which is field assisted to provide high throughput with less wastage and redisposition of the material. The Lorentz field assisted MBE of some embodiments has better control on the atomic or ionic species of the material from an effusion source, and this better control allows for faster deposition rate of the atomic or ionic species to a substrate. Here, the term

"species" refers to the material that is desired to be deposited from an effusion source to a substrate. The Lorentz field assisted MBE of some embodiments use polarized (e.g., charged chemicals) for drift enhancement to reduce the diffusion time and the ionic species from the target to the substrate.

[0016] The Lorentz field assisted MBE of some embodiments use drift enhancement effusion sources for high speed generation of the elemental sources. The Lorentz field assisted MBE of some embodiments allows for control of the charge state of the species. The Lorentz field assisted MBE of some embodiments utilizes Lorentz field optics to reduce the deposition on the side walls of an MBE chamber to increase the utilization of the target elements. In some embodiments, electron beams are used to sputter a target material into a chamber, and this target material can be a compound. As such, deposition time is reduced because compounds can be deposited instead of single elemental material. Other technical effects will be evident from the various embodiments and figures.

[0017] Some embodiments describe a selective area pulsed epitaxy for MBE with two or three sources for growth of ABO3 class of perovskite oxides. In some embodiments, the MBE system comprises of multiple molecular sources A, B, or AA', BB' along with oxygen (O) supply. In some embodiments, the multiple molecular sources A, B, or AA', BB', and O are integrated into an MBE apparatus. In some embodiments, the chemical reaction of A, B, and O is a self-limiting reaction controlled by the stoichiometry of the elements. In some embodiments, a wafer is pre-patterned using standard optical lithography and etch methods. In some embodiments, the pre-patterned wafer comprises of areas with favorable conditions for epitaxy. In some embodiments, a pulsed MBE method comprising of AA', BB' and O is applied to the pre-patterned wafer. In some embodiments, the residual deposit of non- stoichiometric perovskite is removed from the mask regions using a cleaning method.

[0018] The selective area pulsed epitaxy for MBE of various embodiments enables: growth of functional oxides in the preferred locations of a die, growth of meta stable layers stabilized by strain (e.g., uniaxial, biaxial, and rumpled), and quantum mechanical coupling such as magnetoelectric, exchange bias, Dzyaloshinskii-Moriya interactions, etc. The apparatus and method of selective area epitaxy in an MBE system also enables formation of extremely high quality seeding layers, in accordance with some embodiments. In some embodiments, apparatus and method of selective area epitaxy in an MBE system enables propagation of quantum mechanical coupling between starting substrate and grown lattices. Other technical effects of selective area pulsed epitaxy for MBE will be evident from the various embodiments and figures.

[0019] In the following description, numerous details are discussed to provide a more thorough explanation of embodiments of the present disclosure. It will be apparent, however, to one skilled in the art, that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring embodiments of the present disclosure.

[0020] Note that in the corresponding drawings of the embodiments, signals are represented with lines. Some lines may be thicker, to indicate more constituent signal paths, and/or have arrows at one or more ends, to indicate primary information flow direction. Such indications are not intended to be limiting. Rather, the lines are used in connection with one or more exemplary embodiments to facilitate easier understanding of a circuit or a logical unit. Any represented signal, as dictated by design needs or preferences, may actually comprise one or more signals that may travel in either direction and may be implemented with any suitable type of signal scheme.

[0021] Throughout the specification, and in the claims, the term "connected" means a direct connection, such as electrical, mechanical, or magnetic connection between the things that are connected, without any intermediary devices. The term "coupled" means a direct or indirect connection, such as a direct electrical, mechanical, or magnetic connection between the things that are connected or an indirect connection, through one or more passive or active intermediary devices. The term "circuit" or "module" may refer to one or more passive and/or active components that are arranged to cooperate with one another to provide a desired function. The term "signal" may refer to at least one current signal, voltage signal, magnetic signal, or data/clock signal. The meaning of "a," "an," and "the" include plural references. The meaning of "in" includes "in" and "on."

[0022] The term "scaling" generally refers to converting a design (schematic and layout) from one process technology to another process technology and subsequently being reduced in layout area. The term "scaling" generally also refers to downsizing layout and devices within the same technology node. The term "scaling" may also refer to adjusting (e.g., slowing down or speeding up - i.e. scaling down, or scaling up respectively) of a signal frequency relative to another parameter, for example, power supply level. The terms "substantially," "close," "approximately," "near," and "about," generally refer to being within +/- 10% of a target value.

[0023] Unless otherwise specified the use of the ordinal adjectives "first," "second," and "third," etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking or in any other manner.

[0024] For the purposes of the present disclosure, phrases "A and/or B" and "A or B" mean (A), (B), or (A and B). For the purposes of the present disclosure, the phrase "A, B, and/or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

[0025] The terms "left," "right," "front," "back," "top," "bottom," "over," "under," and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. For the purposes of present disclosure the terms "spin" and "magnetic moment" are used equivalently. More rigorously, the direction of the spin is opposite to that of the magnetic moment, and the charge of the particle is negative (such as in the case of electron). [0026] Fig. 1 illustrates a high-level cross-section of an MBE apparatus 100. MBE apparatus 100 mainly consists of chamber 101, effusion sources 102i-4, RHEED (reflection high energy electron diffraction) gun 103, RHEED screen 104, mass spectrometer 105, handle 106, substrate 107, and interface 108 to a buffer chamber.

[0027] Chamber 101 is made from metal and ceramics, and is completely sealed to realize an ultra-high vacuum chamber. Sealing is needed to provide a clean and dust free environment to avoid any contamination that may ruin deposition of material. The temperature inside chamber 101 can typically rise to 500-600 degrees centigrade.

[0028] The effusion sources (or cells) 102i-4 are used to fire precise beams of atoms or molecules into chamber 101 towards substrate 107. For sake of brevity, four effusion sources (or cells) 102i-4 are shown. However, any number of effusion sources (or cells) 102i- 4 may be used. Effusion is the process in which a gas escapes through a hole of a diameter considerably smaller than the mean free path of the molecules. Each effusion source is used to fire off a different material into chamber 101. Effusion sources (or cells) 102i-4 generally comprise of a crucible and an insert with a small bore for effusion to take place. It includes a heater and a place for elemental target material. Effusion sources are used for the evaporation of film materials. One kind of effusion cell for use in MBE follows the design of Knudsen cell (e.g., a thermodynamic system where the escaping gas has to pass through a bore smaller than the thermal mean fee path). Several factors affect performance of a Knudsen cell, which include rapid thermal response, low outgassing rate for materials, and uniformity of heating.

[0029] The substrate 107 may be heated by a filament (not shown) behind it.

Substrate 107 or die is positioned facing down so that it faces the effusion sources (or cells) 102i-4. In MBE, separate beams of different material are fired from effusion sources (or cells) 102i-4 which layer as molecules on the surface of substrate 107 in a very slow manner.

[0030] During operation of the MBE, RHEED gun 103 and screen 104 are used to monitor the growth of the crystal formed on substrate 107 by effusion sources (or cells) 102i- 4. Mass spectrometer 105 is also used to measure performance of the operation. Here, handle 106 can be used to orient the substrate 107, and also provide stability to substrate 107 by holding it in place without vibration. As device dimension shrink over process nodes, fabricating devices with extreme accuracy is highly desirable. While MBE allows for fabricating extremely thin films of molecules in a very precise and controlled manner, it is a very slow process that is not suitable for high volume manufacturing (HVM). For example, crystal growth rate is typically a few microns per hour which makes HVM a challenge. [0031] Figs. 2A-B illustrate effusion sources 200/1011 and 220/1011 of the MBE with different apertures, respectively. Effusion sources 200/101 i and 220/101 i are similar in function and principal, but with different bore sizes. In some embodiments, drift enhanced effusion sources are a tube-like structure that include a heater, source material (e.g., Al, Ga, In, Tl, Si, Ge, Sn, Pb, perovskites, oxides, etc.), cathode plate, anode plate, bore, water cooling, controllable shutter, etc. A simplified form is shown as effusion sources 200/1011 and 220/1011 to highlight the effect of the bore size in drift effusion. Typically, the metal plates (if any) in effusion sources are neutral (e.g., not charged), and material in gas form is allowed to effuse through effusion hole at a rate of:

pAN_A

Rate = ,

^2nMRT

[0032] This rate is, however, very slow. Such slow rate makes traditional MBE apparatus to be unsuitable for integrated chip manufacturing. In some embodiments, to enhance the drift of the material through the effusion hole, the metal plates are charged or biased.

[0033] In some embodiments, plate 201 is an anode and plate 202 is a cathode. In some embodiments, the material for effusion is placed in the space between plates 201 and

202. In some embodiments, material 205 is heated and ionized, and the potential difference between plates 201 and 202 causes material 205 to drift through hole 204/224 towards plate

203. In some embodiments, plate 203 is also biased. For example, plate 203 is charged to be an anode to further enhance speed of ejection of effused material 205. In some embodiments, plate 203 includes a single hole 206 to eject the effused material 205. In some embodiments, plate 203 includes multiple holes (not shown).

[0034] In some embodiments, the electric field applied in the effusion cell due to anode 201 and cathode 202 directs the material molecules 205 to pass through bore 204/224. As the bore size increases from 204 to 224, more molecules pass through. These molecules are then released into chamber 101 at a controlled rate. In some embodiments, a shutter (not shown) is attached to plate 203 and is used to control the number of molecules fired by the effusion cell. For example, the shutter can cover some holes so to reduce the number of molecules released by the effusion cell. The rate of effusion from drift assistance is higher than the traditional rate of effusion without drift assistance, in accordance with various embodiments. [0035] Fig. 3 illustrates an MBE apparatus 300 with drift enhanced deposition, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 3 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such.

[0036] In some embodiments, to increase the speed of deposition of material on substrate 107, a DC (Direct Current) bias is provided to substrate 107. As such MBE apparatus 100 is modified to include a signal path 309 which is coupled to a signal source 310 and substrate 107. Signal path 309 may be formed of any high conductivity material (e.g., Cu, Al, Ag, Au, etc.). In some embodiments, signal path 309 provides a DC bias to substrate 107 to develop an internal electric field to attract the ionized atom 311 from effusion source 3023.

[0037] Compared to effusion sources 102i-4, here effusion sources 302i-4 can provide ionized atoms instead of just uncharged atoms or molecules in gas form. In some embodiments, effusion sources 302i-4 can provide accelerated ionized atoms/molecules for faster deposition on substrate 107 instead of just releasing them in chamber 101. The bias voltage influences the trajectory of the ionized atom/molecule 311 from effusion source 1023 to substrate 107 so that material released by effusion source 1023 is received by substrate 107 and does not miss it.

[0038] In MBE apparatus 100 of Fig. 1, a significant amount of material released by an effusion sources 102i-4 misses the target substrate 107 and ends up sticking to the inner walls of chamber 101. This loss of material causes increased cost of manufacturing and also excessive delays in forming thin film on substrate 107 because not every released molecule ends on substrate 107. Referring back to Fig. 3, in some embodiments, signal source 310 is a voltage source that can provide a bias on signal path 309 such that the bias is one of: a constant positive DC bias; constant negative DC bias; a positive pulse; a negative pulse; a pulse train with fixed pulse widths; or a pulse train with variable pulse widths. In some embodiments, signal source 310 can provide an adjustable bias.

[0039] In some embodiments, the type of bias can be selected to allow for control of the generation rates and the type of charged atoms/molecules collected on substrate 107. For example, a drift field can be used to modulate the flow rate of charged atoms/molecules for MBE. In some embodiments, a positive DC bias can be used to attract negative ions from an effusion source. In some embodiments, a negative DC bias can be used to attract positive ions from an effusion source. The positively charged species experience electromagnetic forces which include an electric field and a magnetic field. The electric field produces a drift in the species which adds kinetic energy to the species, while the magnetic field produces a Lorentz force given by the cross product of the velocity and magnetic field, in accordance with some embodiments. The charge on the molecular/elemental species generated by the sources can be modulated by engineering the source design.

[0040] Fig. 4A illustrates an MBE apparatus 400 with magnetic lensing and drift enhanced diffusion, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 4A having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such.

[0041] In some embodiments, magnetic lensing apparatus 401 and 402 is coupled to chamber 101 to provide magnetic fields 403a and 403b, respectively, to chamber 101. In some embodiments, apparatus 401 and 402 are ferromagnetic cores. In some embodiments, the ferromagnetic cores comprise one or a combination of materials including one or more of a Heusler alloy, Co, Fe, Ni, Gd, B, Ge, Ga, permalloy, and Yttrium Iron Garnet (YIG).

Heusler alloy is ferromagnetic metal alloy based on a Heusler phase. Heusler phase is intermetallic with certain composition and face-centered cubic (FCC) crystal structure. The ferromagnetic property of the Heusler alloy is a result of a double-exchange mechanism between neighboring magnetic ions. In some embodiments, the Heusler alloy is a material selected which includes one of: Cu₂MnAl, Cu₂MnIn, Cu₂MnSn, Ni₂MnAl, Ni₂MnIn,

Ni₂MnSn, Ni₂MnSb, Ni₂MnGa Co₂MnAl, Co₂MnSi, Co₂MnGa, Co₂MnGe, Pd₂MnAl, Pd₂MnIn, PdJVInSn, PdJVInSb, Co₂FeSi, Co₂FeAl, Fe₂VAl, Mn₂VGa, Co₂FeGe, MnGa, or MnGaRu.

[0042] In some embodiments, apparatus 401 and 402 are paramagnets cores which are non-ferromagnetic elements with strong paramagnetism which have high number of unpaired spins but are not room temperature ferromagnets. In some embodiments, apparatus 401 and 402 comprise a material which includes one or more of: Platinum(Pt), Palladium (Pd), Tungsten (W), Cerium (Ce), Aluminum (Al), Lithium (Li), Magnesium (Mg), Sodium (Na), Cr₂Cb (chromium oxide), CoO (cobalt oxide), Dysprosium (Dy), Dy20 (dysprosium oxide), Erbium (Er), EnCb (Erbium oxide), Europium (Eu), EU2O3 (Europium oxide), Gadolinium (Gd), Gadolinium oxide (Gd2C ), FeO and Fe203 (Iron oxide), Neodymium (Nd), Nd203 (Neodymium oxide), KO2 (potassium superoxide), praseodymium (Pr), Samarium (Sm), SrmCb (samarium oxide), Terbium (Tb), Tb203 (Terbium oxide), Thulium (Tm), TrmC (Thulium oxide), and V2O3 (Vanadium oxide). In some embodiments, the apparatus 401 and 402 comprise dopants which include one of: Ce, Cr, Mn, Nb, Mo, Tc, Re, Nd, Gd, Tb, Dy, Ho, Er, Tm, or Yb.

[0043] In some embodiments, the gradient of the magnetic fields 403a and 403b is used to focus the ionized species to substrate 107. In some embodiments, the magnetic fields 403 a and 403b are uniform in that the strength of the fields within chamber 101 is substantially constant. In some embodiments, the magnetic fields 403a and 403b and the electric field from DC bias influence the Lorentz field trajectory to control the direction and path of the MBE species released by the effusion sources. In some embodiments, non- ionized effusion cells (e.g., cells 102M) can be used with magnetic lensing apparatus 401 and

402 without the apparatus for DC bias. In some embodiments, the bias provided to substrate 107 generates an electric field to control deposition energy associated with the material from the effusion source. In some embodiments, the magnetic fields 403 a/b control the momentum (e.g., direction) of material from the effusion source.

[0044] Figs. 4B-C illustrate the operating principle of Lorentz field assist for MBE, according to some embodiments of the disclosure. It is pointed out that those elements of Figs. 4B-C having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. Here, curve 431 shows the trajectory of positively charged species under a magnetic field out of the plane. Curve 432 shows the trajectory of the species under a drift and Lorentz field. The drift field controls the energy while the Lorentz field provides control over the direction (momentum vector), in accordance with some embodiments. Curve 433 shows the trajectory of a negatively charged species under a magnetic field out of plane. Curve 434 shows the trajectory of the negatively charged species under electric and magnetic fields.

[0045] Fig. 5 illustrates an MBE apparatus 500 with an e-beam and drift enhanced diffusion, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 5 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such.

[0046] In some embodiments, MBE apparatus 500 comprises an electron source (e- source or e-beam) 512 and corresponding target cell 513. In some embodiments, e-source 512 and corresponding target cell 513 are partially inserted in chamber 101 like effusion cells 3011-4 or effusion cells lOh-4. In some embodiments, e-source 512 transmits electrons into chamber 101 towards target cell 513. In some embodiments, e-source 512 is like a cathode ray tube (CRT) which is configured to transmit accelerated electrons towards a particular direction. In some embodiments, e-source 512 is aimed and focused towards a particular target 513. While the embodiments show one e-source 512 and corresponding target cell 513, there can be any number of electron sources and corresponding targets inserted into chamber 101. For example, another e-source can be provided which is aimed or focused towards another target cell. In one such example, different target cell 513 can contain different material.

[0047] In some embodiments, target cell 513 includes any material which is desired to be deposited on substrate 107. In some embodiments, the material in target cell 513 is an element in ionized or molecular form. In some embodiments, the material in target cell 513 is a compound. In one such embodiment, when the electron from e-source 512 hits the material in target cell 513, the material sputters into chamber 101 and lands on substrate 107. This is illustrated by trajectory 51 1 of the sputtered material. As such, electrons from e- source 512 are means for transporting material to substrate 107.

[0048] In some embodiments, the rate of deposition of material from target cell 513 to substrate 107 can be increased by DC biasing the substrate 107 as described with reference to Fig. 3. In some embodiments, the rate of deposition of material from target cell 513 to substrate 107 can be increased by providing magnetic field to chamber 101 as described with reference to Fig. 4.

[0049] Referring back to Fig. 5, in some embodiments, electron source 512 and corresponding target cell 513 are provided in addition to DC bias apparatus (e.g., signal path 309 and signal source 310). In some embodiments, electron source 512 and corresponding target cell 513 are provided to chamber 101 in the absence of DC bias apparatus (e.g., signal path 309 and signal source 310). In some embodiments, electron source 512 and

corresponding target cell 513 are provided in addition to magnetic lensing apparatus 401 and 402.

[0050] Fig. 6 illustrates part of the MBE with e-beam source 601/512 and receiver

602/513, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 6 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such.

[0051] In some embodiments, e-beam source 601/512 comprises a filament 603 which is powered by an adjustable power source 601a. In some embodiments, the power source is adjustable using an adjustable capacitor 601b. In some embodiments, filament 603 is housed in a cavity 601c having an aperture 601 d for electrons to pass through. When filament 603 is heated by the power source 601a, electrons are released through aperture 601d into chamber 101. In some embodiments, magnet 607 is provided inside chamber 101 to influence trajectory of electron path 608 so that the electrons released from filament 603 are received by target cell 602/513.

[0052] In some embodiments, target cell 602/513 comprises cooling holder 604 (e.g., water cooled holder to keep target material cool), ingot 605 with target material (e.g., ionized elements, molecules, or compounds), and heated region 606 where target material is heated and ready for sputtering upon interaction with an electron. In some embodiments, when electrons released from filament 603 are received by heated region 606, target material sputters as shown by indicator 609. In some embodiments, this sputtered material is released in chamber 101 and makes it way to substrate 107 where it is deposited. In some

embodiments, when target material is a compound, then a compound can be deposited on substrate 107 which was previously not possible. By further adding drift electric field to chamber 101 using DC bias, high throughput can be achieved for depositing material to substrate 107 from target cell 602/513, in accordance with some embodiments.

[0053] Fig. 7 illustrates a perovskite lattice 700 and possible material sources for use by the effusion sources, in accordance with some embodiments. A perovskite has a cubic structure with general formula of ABCb. In this cubic structure, 'A' represents A-site ion (e.g., alkaline earth or rare earth element) which is positioned on the corners of the lattice, 'B' represents B-site ion (e.g., 3d, 4d, and 5d transition metal elements of the Periodic Table) on the center of the lattice, and oxide Ό' within the lattice forming an angled cube. The periodic table shown in Fig. 7 has elements shaded with three different shades for choices for A, B, and O.

[0054] Figs. 8A-B illustrate a process of selective deposition of perovskites using the

MBE apparatus, according to some embodiments of the disclosure. Fig. 8A illustrates a plot 800 showing three waveforms— Flux A, Flux B, and Flux C. Here, the x-axis is time, and y- axis is flux of the respective material.

[0055] In some embodiments, material A is injected into MBE chamber 101 by an effusion source which is controlled to inject material A as pulses. In some embodiments, material A includes one of: Na, K, Rb, Cs, Ca, Sr, Ba, Lu, Ag, Cd, In, Ti, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Pu, or Am.

[0056] In some embodiments, material B is injected into MBE chamber 101 by an effusion source which is controlled to inject material B as pulses. In some embodiments, material B includes one of: Lu, Mg, Ca, Sr, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Al, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, I, Lu, Hf, Ta, W, Ir, Hg, Pb, Ce, Pr, Hi, Er, Tm, Yb, Th, Pa, U, Np, Pu, or Am.

[0057] In some embodiments, material C is injected into MBE chamber 101 by an effusion source which is controlled to inject material C as a constant supply. In some embodiments, material C includes one of: H, O, F, S, CI, Se, or Br.

[0058] Fig. 8B illustrates a cross-section 820 of a patterned substrate. In some embodiments, substrate 821 (e.g., SiCh or Si) is formed and then pattemed. For example, any standard optical lithography and etching method or process can be used to pattern substrate 821. In some embodiments, layer 822 over substrate 821 is pattemed. In this example, region 823 is where perovskite is deposited. Cross-section 830 illustrates a snapshot 801 of the deposition of materials A, B, and C (labeled as 824, 825, and 826, respectively) on substrate 107 using effusion sources. In some embodiments, during the on periods of the pulses (e.g., when pulses are high), materials A and B deposit uniformly along substrate 840 and on the patterned regions (e.g., trenches). In this example, material C is being constantly deposited along substrate 840 and on the pattemed regions forming perovskites.

[0059] Cross-section 840 illustrates the case when pulses associated with materials A and B are off. In some embodiments, during the off periods of the pulses (e.g., when the pulses are low), materials A and B are desorbed from the energetically unfavorable surfaces (e.g., the areas of the chip covered with masking layer 822 such as SiCh). As such, perovskite are only formed in the pattemed regions.

[0060] In some embodiments, the timing of the pulses can be changed which may result in changing the stoichiometry. For example, pulses for material A and B can be phase shifted relative to one another to change when deposition and desorption takes place. While various embodiments are described with reference to depositing three source materials, the embodiments are applicable to depositing two or more than three sources too.

[0061] Fig. 9 illustrates an MBE apparatus 900 with pulsed deposition of perovskites, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 9 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such.

[0062] In some embodiments, first effusion source 9021 is provided which is at least partially embedded in chamber 101. In some embodiments, first effusion source 902i injects a first material into the chamber, wherein the first material is used for forming a perovskite on the patterned substrate or wafer. In some embodiments, the first material includes one of: Na, K, Rb, Cs, Ca, Sr, Ba, Lu, Ag, Cd, In, Ti, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Pu, or Am.

[0063] In some embodiments, second effusion source 9022 is provided which is at least partially embedded in chamber 101. In some embodiments, second effusion source 9022 injects a second material into chamber 101, wherein the second material is different from the first material, and wherein the second material is to combine with the first material. In some embodiments, the second material includes one of: Na, K, Rb, Cs, Ca, Sr, Ba, Lu, Ag, Cd, In, Ti, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Pu, or Am.

[0064] In some embodiments, third effusion source 9023 is provided which at least partially embedded in chamber 101. In some embodiments, the third effusion source 9023 injects a third material to combine with the first and second materials. In some embodiments, the third material includes one of: H, O, F, S, CI, Se, or Br.

[0065] In some embodiments, signal source 310 biases the patterned substrate to influence a trajectory of the first, second, and third materials from the first, second, and third effusion sources, respectively, to the patterned substrate. As such, selective area MBE is performed in a faster manner. In some embodiments, first effusion source 902i is biased to output the first material in pulses (e.g., as shown with reference to Flux A of Fig. 8A). In some embodiments, first effusion source 902i comprises a shutter which is controlled to cause the first material to be injected into chamber 101 as pulses. In some embodiments, the second effusion source 9022 is biased to output the second material in pulses (e.g., as shown with reference to Flux B of Fig. 8A). In some embodiments, the second effusion source 9022 comprises a shutter which is controlled to cause the second material to be injected into chamber 101 as pulses. In some embodiments, third effusion source 9023 provides a constant supply of material C (e.g., as shown with reference to Flux C of Fig. 8A). In some embodiments, the pulses associated with second material are phase shifted relative to the pulses associated with the first material.

[0066] Fig. 10 illustrates flowchart 1000 of a method of selective deposition of perovskites, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 10 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such. The various blocks can be operated or executed in parallel, in a sequence, or in a different order than what is shown in Fig. 10. Some blocks may be replaced with other blocks for the selective deposition of perovskites. [0067] At block 1001, a substrate is patterned, wherein the substrate is positioned in chamber 101 for MBE. Any standard optical lithography and etch method can be used for patterning the substrate. At block 1002, a first material is injected into chamber 101, wherein the first material is used for forming a perovskite on the patterned substrate. At block 1003, a second material is injected into chamber 101, wherein the second material being different from the first material, wherein the second material is to combine with the first material. At block 1004, a third material is injected into chamber 101, wherein the third chamber is to combine with the first and second materials. At block 1005, the patterned substrate is biased so as to influence a trajectory of the first, second, and third materials from the first, second, and third effusion sources, respectively, to the patterned substrate. At block 1006, a first effusion source is biased to output the first material in pulses. At block 1007, a second effusion source is biased to output the second material in pulses. At block 1008, the pulses associated with second material is phase shifted relative to the pulses associated with the first material. At block 1009, the third material is provided as a constant supply to chamber 101. At block 1010, a shutter associated with the first effusion source is controlled to cause the first material to be injected into the chamber as pulses. At block 1011, a shutter associated with the second effusion source is controlled to cause the second material to be injected into the chamber as pulses.

[0068] In some embodiments, the first material includes one of: Na, K, Rb, Cs, Ca,

Sr, Ba, Lu, Ag, Cd, In, Ti, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Pu, or Am. In some embodiments, the second material includes one of: Lu, Mg, Ca, Sr, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Al, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, I, Lu, Hf, Ta, W, Ir, Hg, Pb, Ce, Pr, Hi, Er, Tm, Yb, Th, Pa, U, Np, Pu, or Am. In some embodiments, the third material includes one of: H, O, F, S, CI, Se, or Br.

[0069] Fig. 11 illustrates a smart device or a computer system or a SoC (System-on-

Chip) having a substrate processed by MBE, according to some embodiments of the disclosure. It is pointed out that those elements of Fig. 11 having the same reference numbers (or names) as the elements of any other figure can operate or function in any manner similar to that described, but are not limited to such.

[0070] For purposes of the embodiments, the transistors in various circuits and logic blocks described here are metal oxide semiconductor (MOS) transistors or their derivatives, where the MOS transistors include drain, source, gate, and bulk terminals. The transistors and/or the MOS transistor derivatives also include Tri-Gate and FinFET transistors, Gate All Around Cylindrical Transistors, Tunneling FET (TFET), Square Wire, or Rectangular Ribbon Transistors, ferroelectric FET (FeFETs), or other devices implementing transistor functionality like carbon nanotubes or spintronic devices. MOSFET symmetrical source and drain terminals i.e., are identical terminals and are interchangeably used here. A TFET device, on the other hand, has asymmetric Source and Drain terminals. Those skilled in the art will appreciate that other transistors, for example, Bi-polar junction transistors (BJT PNP/NPN), BiCMOS, CMOS, etc., may be used without departing from the scope of the disclosure.

[0071] Fig. 11 illustrates a block diagram of an embodiment of a mobile device in which flat surface interface connectors could be used. In some embodiments, computing device 1600 represents a mobile computing device, such as a computing tablet, a mobile phone or smart-phone, a wireless-enabled e-reader, or other wireless mobile device. It will be understood that certain components are shown generally, and not all components of such a device are shown in computing device 1600.

[0072] In some embodiments, computing device 1600 includes first processor 1610 formed using MBE, according to some embodiments discussed. Other blocks of the computing device 1600 may also be formed using MBE, according to some embodiments. The various embodiments of the present disclosure may also comprise a network interface within 1670 such as a wireless interface so that a system embodiment may be incorporated into a wireless device, for example, cell phone or personal digital assistant.

[0073] In some embodiments, processor 1610 (and/or processor 1690) can include one or more physical devices, such as microprocessors, application processors,

microcontrollers, programmable logic devices, or other processing means. The processing operations performed by processor 1610 include the execution of an operating platform or operating system on which applications and/or device functions are executed. The processing operations include operations related to I/O (input/output) with a human user or with other devices, operations related to power management, and/or operations related to connecting the computing device 1600 to another device. The processing operations may also include operations related to audio I/O and/or display I/O.

[0074] In some embodiments, computing device 1600 includes audio subsystem

1620, which represents hardware (e.g., audio hardware and audio circuits) and software (e.g., drivers, codecs) components associated with providing audio functions to the computing device. Audio functions can include speaker and/or headphone output, as well as microphone input. Devices for such functions can be integrated into computing device 1600, or connected to the computing device 1600. In one embodiment, a user interacts with the computing device 1600 by providing audio commands that are received and processed by processor 1610.

[0075] In some embodiments, computing device 1600 comprises display subsystem

1630. Display subsystem 1630 represents hardware (e.g., display devices) and software (e.g., drivers) components that provide a visual and/or tactile display for a user to interact with the computing device 1600. Display subsystem 1630 includes display interface 1632, which includes the particular screen or hardware device used to provide a display to a user. In one embodiment, display interface 1632 includes logic separate from processor 1610 to perform at least some processing related to the display. In one embodiment, display subsystem 1630 includes a touch screen (or touch pad) device that provides both output and input to a user.

[0076] In some embodiments, computing device 1600 comprises I/O controller 1640.

I/O controller 1640 represents hardware devices and software components related to interaction with a user. I/O controller 1640 is operable to manage hardware that is part of audio subsystem 1620 and/or display subsystem 1630. Additionally, I/O controller 1640 illustrates a connection point for additional devices that connect to computing device 1600 through which a user might interact with the system. For example, devices that can be attached to the computing device 1600 might include microphone devices, speaker or stereo systems, video systems or other display devices, keyboard or keypad devices, or other I/O devices for use with specific applications such as card readers or other devices.

[0077] As mentioned above, I/O controller 1640 can interact with audio subsystem

1620 and/or display subsystem 1630. For example, input through a microphone or other audio device can provide input or commands for one or more applications or functions of the computing device 1600. Additionally, audio output can be provided instead of, or in addition to display output. In another example, if display subsystem 1630 includes a touch screen, the display device also acts as an input device, which can be at least partially managed by I/O controller 1640. There can also be additional buttons or switches on the computing device 1600 to provide I/O functions managed by I/O controller 1640.

[0078] In some embodiments, I/O controller 1640 manages devices such as accelerometers, cameras, light sensors or other environmental sensors, or other hardware that can be included in the computing device 1600. The input can be part of direct user interaction, as well as providing environmental input to the system to influence its operations (such as filtering for noise, adjusting displays for brightness detection, applying a flash for a camera, or other features). [0079] In some embodiments, computing device 1600 includes power management

1650 that manages battery power usage, charging of the battery, and features related to power saving operation. Memory subsystem 1660 includes memory devices for storing information in computing device 1600. Memory can include nonvolatile (state does not change if power to the memory device is interrupted) and/or volatile (state is indeterminate if power to the memory device is interrupted) memory devices. Memory subsystem 1660 can store application data, user data, music, photos, documents, or other data, as well as system data (whether long-term or temporary) related to the execution of the applications and functions of the computing device 1600.

[0080] Elements of embodiments are also provided as a machine-readable medium

(e.g., memory 1660) for storing the computer-executable instructions (e.g., instructions to implement any other processes discussed herein). The machine-readable medium (e.g., memory 1660) may include, but is not limited to, flash memory, optical disks, CD-ROMs, DVD ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, phase change memory (PCM), or other types of machine-readable media suitable for storing electronic or computer- executable instructions. For example, embodiments of the disclosure may be downloaded as a computer program (e.g., BIOS) which may be transferred from a remote computer (e.g., a server) to a requesting computer (e.g., a client) by way of data signals via a communication link (e.g., a modem or network connection).

[0081] In some embodiments, computing device 1600 comprises connectivity 1670.

Connectivity 1670 includes hardware devices (e.g., wireless and/or wired connectors and communication hardware) and software components (e.g., drivers, protocol stacks) to enable the computing device 1600 to communicate with external devices. The computing device 1600 could be separate devices, such as other computing devices, wireless access points or base stations, as well as peripherals such as headsets, printers, or other devices.

[0082] Connectivity 1670 can include multiple different types of connectivity. To generalize, the computing device 1600 is illustrated with cellular connectivity 1672 and wireless connectivity 1674. Cellular connectivity 1672 refers generally to cellular network connectivity provided by wireless carriers, such as provided via GSM (global system for mobile communications) or variations or derivatives, CDMA (code division multiple access) or variations or derivatives, TDM (time division multiplexing) or variations or derivatives, or other cellular service standards. Wireless connectivity (or wireless interface) 1674 refers to wireless connectivity that is not cellular, and can include personal area networks (such as Bluetooth, Near Field, etc.), local area networks (such as Wi-Fi), and/or wide area networks (such as WiMax), or other wireless communication.

[0083] In some embodiments, computing device 1600 comprises peripheral connections 1680. Peripheral connections 1680 include hardware interfaces and connectors, as well as software components (e.g., drivers, protocol stacks) to make peripheral connections. It will be understood that the computing device 1600 could both be a peripheral device ("to" 1682) to other computing devices, as well as have peripheral devices ("from" 1684) connected to it. The computing device 1600 commonly has a "docking" connector to connect to other computing devices for purposes such as managing (e.g., downloading and/or uploading, changing, synchronizing) content on computing device 1600. Additionally, a docking connector can allow computing device 1600 to connect to certain peripherals that allow the computing device 1600 to control content output, for example, to audiovisual or other systems.

[0084] In addition to a proprietary docking connector or other proprietary connection hardware, the computing device 1600 can make peripheral connections 1680 via common or standards-based connectors. Common types can include a Universal Serial Bus (USB) connector (which can include any of a number of different hardware interfaces), DisplayPort including MiniDisplayPort (MDP), High Definition Multimedia Interface (HDMI), Firewire, or other types.

[0085] Reference in the specification to "an embodiment," "one embodiment," "some embodiments," or "other embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments. The various appearances of "an embodiment," "one embodiment," or "some embodiments" are not necessarily all referring to the same embodiments. If the specification states a component, feature, structure, or characteristic "may," "might," or "could" be included, that particular component, feature, structure, or characteristic is not required to be included. If the specification or claim refers to "a" or "an" element, that does not mean there is only one of the elements. If the specification or claims refer to "an additional" element, that does not preclude there being more than one of the additional element.

[0086] Furthermore, the particular features, structures, functions, or characteristics may be combined in any suitable manner in one or more embodiments. For example, a first embodiment may be combined with a second embodiment anywhere the particular features, structures, functions, or characteristics associated with the two embodiments are not mutually exclusive.

[0087] While the disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations of such embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description. The embodiments of the disclosure are intended to embrace all such alternatives, modifications, and variations as to fall within the broad scope of the appended claims.

[0088] In addition, well known power/ground connections to integrated circuit (IC) chips and other components may or may not be shown within the presented figures, for simplicity of illustration and discussion, and so as not to obscure the disclosure. Further, arrangements may be shown in block diagram form in order to avoid obscuring the disclosure, and also in view of the fact that specifics with respect to implementation of such block diagram arrangements are highly dependent upon the platform within which the present disclosure is to be implemented (i.e., such specifics should be well within purview of one skilled in the art). Where specific details (e.g., circuits) are set forth in order to describe example embodiments of the disclosure, it should be apparent to one skilled in the art that the disclosure can be practiced without, or with variation of, these specific details. The description is thus to be regarded as illustrative instead of limiting.

[0089] The following examples pertain to further embodiments. Specifics in the examples may be used anywhere in one or more embodiments. All optional features of the apparatus described herein may also be implemented with respect to a method or process.

[0090] Example 1 is an apparatus comprising: a chamber for molecular beam epitaxy

(MBE); an effusion source at least partially embedded in the chamber; a handle in the chamber to hold a substrate; and a signal source to provide a bias to the substrate, wherein the bias is to influence a traj ectory of a material from the effusion source to the substrate.

[0091] Example 2 includes all features of example 1 , wherein the bias is one of: a constant positive DC bias; a constant negative DC bias; a pulse; a pulse train with fixed pulse widths; or a pulse train with variable pulse widths.

[0092] Example 3 is according to any one of examples 1 or 2, wherein the effusion source is to provide ionized effused atoms or molecules of the material.

[0093] Example 4 is according to any one of examples 1 or 3 comprises a reflection high energy electron diffraction (RHEED) gun at least partially embedded in the chamber.

[0094] Example 5 is according to any one of examples 1 or 4 comprises an electron source at least partially embedded in the chamber. [0095] Example 6 includes all features of example 5 and comprises a target cell to receive electrons from the electron source, and to sputter a material into the chamber.

[0096] Example 7 includes all features of example 6, wherein the material is an elemental module or a compound of two or more elements.

[0097] Example 8 is according to any one of examples 1 or 5 comprises a mass spectrometer which is partially embedded in the chamber.

[0098] Example 9 is according to any of the preceding examples, wherein the bias is to generate an electric field which is applied to the substrate.

[0099] Example 10 is according to any of the preceding examples and comprises a magnetic lensing device coupled to the chamber, wherein the magnetic lensing device is to apply a magnetic field to the chamber to influence the trajectory of the material from the effusion source to the substrate.

[00100] Example 11 is apparatus which comprises: a chamber for molecular beam epitaxy (MBE); an effusion source at least partially embedded in the chamber; a handle in the chamber to hold a substrate; and a magnetic lensing device coupled to the chamber, wherein the magnetic lensing device is to apply a magnetic field to the chamber to influence a trajectory of a material from the effusion source to the substrate.

[00101] Example 12 includes all features of example 11, and comprises a signal source to provide a bias to the substrate, wherein the bias is to influence the trajectory of the material from the effusion source to the substrate.

[00102] Example 13 includes all features of example 12, wherein the bias is to generate an electric field to control deposition energy associated with the material from the effusion source.

[00103] Example 14 is according to any one of examples 11 to 13, wherein the magnetic field is to control the momentum of material from the effusion source.

[00104] Example 15 includes all features of example 12 and includes features according to any of example 2 to 9.

[00105] Example 16 is a method which comprises: embedding an effusion source at least partially in a chamber for molecular beam epitaxy (MBE); holding a substrate in the chamber; and providing a bias to the substrate, wherein the bias is to influence a trajectory of a material from the effusion source to the substrate.

[00106] Example 17 includes all features of example 16, wherein the bias is one of: a constant positive DC bias; a constant negative DC bias; a pulse; a pulse train with fixed pulse widths; or a pulse train with variable pulse widths. [00107] Example 18 is according to any one of examples 16 or 17, and comprises providing ionized effused atoms of the material to the chamber.

[00108] Example 19 is according to any one of examples 16 or 17, and comprises monitoring growth of a film on the substrate via a reflection high energy electron diffraction (RHEED) gun which is at least partially embedded in the chamber.

[00109] Example 20 is according to any one of examples 16 or 17, and comprises transmitting electrons in the chamber via an electron source which is at least partially embedded in the chamber.

[00110] Example 21 is according to any one of examples 16 or 17, and comprises applying a magnetic field to the chamber to influence the trajectory of the material from the effusion source to the substrate.

[00111] Example 22 is an apparatus which comprises: means for molecular beam epitaxy (MBE); means for providing ionized effused atoms of a material into the means for MBE; means for holding a substrate; and means for providing a bias to the substrate, wherein the bias is to influence a trajectory of the material to the substrate.

[00112] Example 23 includes all features of example 22, wherein the bias is one of: a constant positive DC bias; a constant negative DC bias; a pulse; a pulse train with fixed pulse widths; or a pulse train with variable pulse widths.

[00113] Example 24 includes all features of example 22, and comprises means for applying a magnetic field to influence the trajectory of the material to the substrate.

[00114] Example 25 is an apparatus which comprises: a chamber for molecular beam epitaxy (MBE); a handle in the chamber to hold a patterned substrate; and a first effusion source at least partially embedded in the chamber, the first effusion source to inject a first material into the chamber, wherein the first material is used for forming a perovskite on the patterned substrate; a second effusion source at least partially embedded in the chamber, the second effusion source to inject a second material into the chamber, the second material being different from the first material, wherein the second material is to combine with the first material; and a third effusion source at least partially embedded in the chamber, the third effusion source to inject a third material to combine with the first and second materials.

[00115] Example 26 includes all features of example 25, and comprises: a signal source to provide a bias to the substrate, wherein the bias is to influence a trajectory of the first, second, and third materials from the first, second, and third effusion sources, respectively, to the patterned substrate. [00116] Example 27 is according to any one of examples 25 to 26, wherein the first effusion source is biased to output the first material in pulses.

[00117] Example 28 is according to any one of examples 25 to 26, wherein the second effusion source is biased to output the second material in pulses.

[00118] Example 29 includes all features of example 28, wherein the pulses associated with second material are phase shifted relative to the pulses associated with the first material.

[00119] Example 30 includes all features of example 28, wherein the third effusion source is to provide the third material as a constant supply.

[00120] Example 31 is according to any one of examples 25 to 26, wherein the first effusion source comprises a shutter which is controlled to cause the first material to be injected into the chamber as pulses.

[00121] Example 32 is according to any one of examples 25 to 26, wherein the second effusion source comprises a shutter which is controlled to cause the second material to be injected into the chamber as pulses.

[00122] Example 33 includes all features of example 32, wherein the pulses associated with second material are phase shifted relative to the pulses associated with the first material.

[00123] Example 34 includes all features of example 33, wherein the third effusion source is to provide the third material as a constant supply.

[00124] Example 35 is according to any one of examples 25 to 34, wherein the first material includes one of: Na, K, Rb, Cs, Ca, Sr, Ba, Lu, Ag, Cd, In, Ti, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Pu, or Am.

[00125] Example 36 is according to any one of examples 25 to 34, wherein the second material includes one of: Lu, Mg, Ca, Sr, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Al, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, I, Lu, Hf, Ta, W, Ir, Hg, Pb, Ce, Pr, Hi, Er, Tm, Yb, Th, Pa, U, Np, Pu, or Am.

[00126] Example 37 is according to any one of examples 25 to 34, wherein the third material includes one of: H, O, F, S, CI, Se, or Br.

[00127] Example 38 is a method for selective area epitaxy, the method comprises: patterning a substrate, wherein the substrate is positioned in a chamber for molecular beam epitaxy (MBE) injecting a first material into the chamber, wherein the first material is used for forming a perovskite on the patterned substrate; injecting a second material into the chamber, wherein the second material being different from the first material, wherein the second material is to combine with the first material; and injecting a third material to combine with the first and second materials. [00128] Example 39 includes all features of example 38, and comprises biasing the patterned substrate, wherein the bias is to influence a trajectory of the first, second, and third materials from the first, second, and third effusion sources, respectively, to the patterned substrate.

[00129] Example 40 is according to any one of examples 38 to 39, and comprises biasing a first effusion source to output the first material in pulses.

[00130] Example 41 is according to any one of examples 38 to 39, and comprises biasing a second effusion source to output the second material in pulses.

[00131] Example 42 includes features of examples of 38 to 39, and comprises phase shifting the pulses associated with second material relative to the pulses associated with the first material.

[00132] Example 43 includes features of example 42, and comprises providing the third material as a constant supply.

[00133] Example 44 is according to any one of examples 38 to 43, and comprises controlling a shutter to cause the first material to be injected into the chamber as pulses.

[00134] Example 45 is according to any one of examples 38 to 43, and comprises controlling a shutter to cause the second material to be injected into the chamber as pulses.

[00135] Example 46 is according to any one of examples 38 to 43, wherein the first material includes one of: Na, K, Rb, Cs, Ca, Sr, Ba, Lu, Ag, Cd, In, Ti, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Pu, or Am.

[00136] Example 47 is according to any one of examples 38 to 43, wherein the second material includes one of: Lu, Mg, Ca, Sr, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Al, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, I, Lu, Hf, Ta, W, Ir, Hg, Pb, Ce, Pr, Hi, Er, Tm, Yb, Th, Pa, U, Np, Pu, or Am.

[00137] Example 48 is according to any one of claims 38 to 43, wherein the third material includes one of: H, O, F, S, CI, Se, or Br.

[00138] Example 49 is an apparatus for selective area epitaxy, the apparatus comprises: means for patterning a substrate, wherein the substrate is positioned in a chamber for molecular beam epitaxy (MBE); means for injecting a first material into the chamber, wherein the first material is used for forming a perovskite on the patterned substrate; means for injecting a second material into the chamber, wherein the second material being different from the first material, wherein the second material is to combine with the first material; and means for injecting a third material to combine with the first and second materials. [00139] Example 50 includes all features of example 49, and comprises means for biasing the patterned substrate, wherein the bias is to influence a trajectory of the first, second, and third materials from the first, second, and third effusion sources, respectively, to the patterned substrate.

[00140] Example 51 is according to any one of examples 49 to 50, and comprises means for biasing a first effusion source to output the first material in pulses.

[00141] Example 52 is according to any one of examples 49 to 50, and comprises means for biasing a second effusion source to output the second material in pulses.

[00142] Example 53 includes features of examples 49 and 50, and comprises means for phase shifting the pulses associated with second material relative to the pulses associated with the first material.

[00143] Example 54 includes all features of example 52, and comprises means for providing the third material as a constant supply.

[00144] Example 55 is according to any one of examples 49 to 54, and comprises means for controlling a shutter to cause the first material to be injected into the chamber as pulses.

[00145] Example 56 is according to any one of examples 49 to 54, and comprises means for controlling a shutter to cause the second material to be injected into the chamber as pulses.

[00146] Example 57 is according to any one of examples 49 to 56, wherein the first material includes one of: Na, K, Rb, Cs, Ca, Sr, Ba, Lu, Ag, Cd, In, Ti, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Pu, or Am.

[00147] Example 58 is according to any one of examples 49 to 56, wherein the second material includes one of: Lu, Mg, Ca, Sr, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Al, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sn, Sb, I, Lu, Hf, Ta, W, Ir, Hg, Pb, Ce, Pr, Hi, Er, Tm, Yb, Th, Pa, U, Np, Pu, or Am.

[00148] Example 59 is according to any one of examples 49 to 56, wherein the third material includes one of: H, O, F, S, CI, Se, or Br.

[00149] An abstract is provided that will allow the reader to ascertain the nature and gist of the technical disclosure. The abstract is submitted with the understanding that it will not be used to limit the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.

Claims

CLAIMS We claim:

1. An apparatus comprising:

a chamber for molecular beam epitaxy (MBE);

an effusion source at least partially embedded in the chamber;

a handle in the chamber to hold a substrate; and

a signal source to provide a bias to the substrate, wherein the bias is to influence a traj ectory of a material from the effusion source to the substrate.

2. The apparatus of claim 1 , wherein the bias is one of:

a constant positive DC bias;

a constant negative DC bias;

a pulse;

a pulse train with fixed pulse widths; or

a pulse train with variable pulse widths.

3. The apparatus according to any one of claims 1 or 2, wherein the effusion source is to provide ionized effused atoms or molecules of the material.

4. The apparatus according to any one of claims 1 or 3 comprises a reflection high energy electron diffraction (RHEED) gun at least partially embedded in the chamber.

5. The apparatus according to any one of claims 1 or 4 comprises an electron source at least partially embedded in the chamber.

6. The apparatus of claim 5 comprises a target cell to receive electrons from the electron source, and to sputter a material into the chamber.

7. The apparatus of claim 6, wherein the material is an elemental module or a compound of two or more elements.

8. The apparatus according to any one of claims 1 or 5 comprises a mass spectrometer which is partially embedded in the chamber.

9. The apparatus according to any of the preceding claims, wherein the bias is to generate an electric field which is applied to the substrate.

10. The apparatus according to any of the preceding claims comprises a magnetic lensing device coupled to the chamber, wherein the magnetic lensing device is to apply a magnetic field to the chamber to influence the traj ectory of the material from the effusion source to the substrate.

1 1. An apparatus comprising:

a chamber for molecular beam epitaxy (MBE);

an effusion source at least partially embedded in the chamber;

a handle in the chamber to hold a substrate; and

a magnetic lensing device coupled to the chamber, wherein the magnetic lensing device is to apply a magnetic field to the chamber to influence a traj ectory of a material from the effusion source to the substrate.

12. The apparatus of claim 1 1 comprises a signal source to provide a bias to the substrate, wherein the bias is to influence the trajectory of the material from the effusion source to the substrate.

13. The apparatus of claim 12, wherein the bias is to generate an electric field to control deposition energy associated with the material from the effusion source.

14. The apparatus according to any one of claims 11 to 13, wherein the magnetic field is to control the momentum of material from the effusion source.

15. The apparatus of claim 12 according to any of claims 2 to 9.

16. A method comprising:

embedding an effusion source at least partially in a chamber for molecular beam epitaxy (MBE);

holding a substrate in the chamber; and

providing a bias to the substrate, wherein the bias is to influence a trajectory of a material from the effusion source to the substrate.

17. The method of claim 16, wherein the bias is one of:

a constant positive DC bias;

a constant negative DC bias;

a pulse;

a pulse train with fixed pulse widths; or

a pulse train with variable pulse widths.

18. The method according to any one of claims 16 or 17 comprises providing ionized effused atoms of the material to the chamber.

19. The method according to any one of claims 16 or 17 comprises monitoring growth of a film on the substrate via a reflection high energy electron diffraction (RHEED) gun which is at least partially embedded in the chamber.

20. The method according to any one of claims 16 or 17 comprises transmitting electrons in the chamber via an electron source which is at least partially embedded in the chamber.

21. The method according to any one of claims 16 or 17 comprises applying a magnetic field to the chamber to influence the trajectory of the material from the effusion source to the substrate.

22. An apparatus comprising:

means for molecular beam epitaxy (MBE);

means for providing ionized effused atoms of a material into the means for MBE; means for holding a substrate; and

means for providing a bias to the substrate, wherein the bias is to influence a traj ectory of the material to the substrate.

23. The apparatus of claim 22, wherein the bias is one of:

a constant positive DC bias;

a constant negative DC bias;

a pulse;

a pulse train with fixed pulse widths; or

a pulse train with variable pulse widths.

24. The apparatus of claim 22 comprising means for applying a magnetic field to influence the trajectory of the material to the substrate.

25. An apparatus comprising:

a chamber for molecular beam epitaxy (MBE);

a handle in the chamber to hold a patterned substrate; and

a first effusion source at least partially embedded in the chamber, the first effusion source to inj ect a first material into the chamber, wherein the first material is used for forming a perovskite on the patterned substrate;

a second effusion source at least partially embedded in the chamber, the second effusion source to inject a second material into the chamber, the second material being different from the first material, wherein the second material is to combine with the first material; and

a third effusion source at least partially embedded in the chamber, the third effusion source to inj ect a third material to combine with the first and second materials;

26. The apparatus of claim 25 comprises a signal source to provide a bias to the substrate, wherein the bias is to influence a trajectory of the first, second, and third materials from the first, second, and third effusion sources, respectively, to the patterned substrate.