High speed semiconductor chip stack
11257762 · 2022-02-22
Inventors
Cpc classification
H01L2223/6655
ELECTRICITY
H01L2223/6677
ELECTRICITY
H01G4/33
ELECTRICITY
International classification
Abstract
The present invention ultra-low loss high energy density dielectric layers having femtosecond (10.sup.−15 sec) polarization response times within a chip stack assembly to extend impedance-matched electrical lengths and mitigate ringing within the chip stack to bring the operational clock speed of the stacked system closer to the intrinsic clock speed(s) of the semiconductor die bonded within chip stack.
Claims
1. A high-speed semiconductor chip stack forming an electrical circuit further comprises one or more physical layers of garnet electroceramic that functions as a high permeability magnetic core material within an inductive element and said one or more physical layers are integrated as part of at least one surface feature on a semiconductor die or on an interposer embedded within the high-speed semiconductor chip stack, wherein the at least one surface feature is a planar inductor element including a serpentine conducting element wound through the garnet electroceramic and inserted between two electrical shorts in communication with via, electrical ground or a transmission line.
2. The high-speed semiconductor chip stack of claim 1, wherein the high permeability garnet electroceramic and adopts either a rhombic dodecahedron or trapezohedron crystal structure, or a combination of the two crystal structures.
3. The high-speed semiconductor chip stack of claim 1, wherein the high permeability garnet electroceramic comprises a uniform distribution of ceramic grains with a grain size diameter ranging from 10 nm to 25 nm.
4. The high-speed semiconductor chip stack of claim 3, wherein the garnet electroceramic forming said high permeability core further comprises a uniform distribution of ceramic grains with a grain size diameter preferably ranging from 250 nm to 5 nm.
5. The high-speed semiconductor chip stack electroceramic of claim 1 that comprises an MB2(SiO4)3 chemical formula, where the preferred Group A metal oxides comprise calcium oxide (CaO), magnesium oxide (MgO), iron oxide (FeO), and manganese oxide (MnO), and the preferred Group B metal oxides comprise aluminum oxide (Al2O3), iron oxide (Fe2O3), chromium oxide (Cr2O3), vanadium oxide (V2O3), zirconium oxide (ZrO2), titanium oxide (TiO2), silicon oxide (SiO2), yttrium oxide (Y2O3), cobalt oxide (Co3O4), gadolinium oxide (Gd2O3) neodymium oxide (Nd2O3) and holmium oxide (Ho2O3).
6. The high-speed semiconductor chip stack electroceramic of claim 5 that comprises an admixture of Group A metal oxides consisting of calcium oxide (CaO), magnesium oxide (MgO), iron oxide (FeO), and manganese oxide (MnO).
7. The high-speed semiconductor chip stack electroceramic of claim 5 that comprises an admixture of Group B metal oxides consisting of aluminum oxide (Al2O3), iron oxide (Fe2O3), chromium oxide (Cr2O3), vanadium oxide (V2O3), zirconium oxide (ZrO2) titanium oxide (TiO2), silicon oxide (SiO2), yttrium oxide (Y2O3), cobalt oxide (Co3O4), gadolinium oxide (Gd2O3) neodymium oxide (Nd2O3) and holmium oxide (Ho2O3).
8. The high-speed semiconductor chip stack electroceramic of claim 5 that comprises an admixture of Group A metal oxides consisting of calcium oxide (CaO), magnesium oxide (MgO), iron oxide (FeO), and manganese oxide (MnO), and an admixture of Group B metal oxides consisting of aluminum oxide (Al2O3), iron oxide (Fe2O3), chromium oxide (Cr2O3), vanadium oxide (V2O3), zirconium oxide (ZrO2), titanium oxide (TiO2), silicon oxide (SiO2), yttrium oxide (Y2O3), cobalt oxide (Co3O4), gadolinium oxide (Gd2O3) neodymium oxide (Nd2O3) and holmium oxide (Ho2O3).
9. The high-speed semiconductor chip stack of claim 1, wherein the surface feature is deployed to terminate an electrical discontinuity in the electrical circuit.
10. The high-speed semiconductor chip stack of claim 1, wherein the surface feature is deployed along a transmission line.
11. The high-speed semiconductor chip stack of claim 10, wherein the surface feature and transmission line are deployed on a semiconductor die.
12. The high-speed semiconductor ship stack of claim 10, wherein the surface feature and transmission line are deployed on an interposer.
13. The high-speed semiconductor chip stack of claim 9, wherein the surface feature is deployed at a via.
14. The high-speed semiconductor chip stack of claim 13, wherein the surface feature and the via are deployed on a semiconductor die.
15. The high-speed semiconductor chip stack of claim 13, wherein the surface feature and the via are deployed on an interposer.
16. A high-speed semiconductor chip stack forming an electrical circuit further comprises one or more physical layers of garnet electroceramic that functions as a high permeability magnetic core material within an inductive element and said one or more physical layers are integrated as part of at least one surface feature on a semiconductor die or on an interposer embedded within the high-speed semiconductor ship stack, wherein the at least one surface feature minimizes the reflections of higher frequency harmonics such that an operational system clock speed of the high-speed semiconductor chip stack optimally matches the slowest clock speed of the semiconductor die embedded within the high speed semiconductor chip stack.
17. The high-speed semiconductor chip stack of claim 16, wherein one or more embedded semiconductor die perform an optical or electro-optical circuit function.
18. The high-speed semiconductor chip stack of claim 16, wherein one or more embedded semiconductor die is a component of a wireless transmitter, wireless receiver, or wireless transceiver circuit module.
19. The high-speed semiconductor chip stack of claim 1, wherein an ultra-low loss material is used as an air gap material between the inductive element and the garnet electroceramic.
20. The high-speed semiconductor chip stack of claim 1, wherein an ultra-low loss material layer, preferably amorphous, is embedded within the magnetic core.
21. The high-speed semiconductor chip stack of claim 20, wherein the ultra-low loss material layer thickness measures 1-10 nm.
22. The high-speed semiconductor chip stack of claim 1, wherein the garnet electroceramic provides magnetic permeability of μr≥10 while at the same time minimizing reflections of higher frequency harmonics to enable operation of the semiconductor chip stack at GHz frequencies.
23. The high-speed semiconductor chip stack of claim 1, wherein the garnet electroceramic includes a characteristic impedance that is matched to the input and input impedance of the semiconductor die.
24. The high-speed semiconductor chip stack of claim 10, wherein the garnet electroceramic is configured to cause the transmission line to resonate at a frequency that matches a clock speed of the semiconductor die.
Description
DETAILED DESCRIPTION OF THE DRAWINGS
(1) The present invention is illustratively described above in reference to the disclosed embodiments. Various modifications and changes may be made to the disclosed embodiments by persons skilled in the art without departing from the scope of the present invention as defined in the appended claims.
(2) This application incorporates by reference all matter contained in de Rochemont U.S. Pat. No. 7,405,698 entitled “CERAMIC ANTENNA MODULE AND METHODS OF MANUFACTURE THEREOF” (the '698 application), de Rochemont U.S. Pat. No. 8,715,839 filed Jun. 30, 2006, entitled “ELECTRICAL COMPONENT AND METHOD OF MANUFACTURE” (the '839 application), U.S. Pat. No. 8,350,657 (the '657 application), filed Jan. 6, 2007 entitled “POWER MANAGEMENT MODULE AND METHODS OF MANUFACTURE”, de Rochemont U.S. Ser. No. 14/560,935, (the '935 application), filed Dec. 4, 2014 entitled “POWER MANAGEMENT MODULE AND METHODS OF MANUFACTURE”, de Rochemont and Kovacs, U.S. Pat. No. 8,715,814, “LIQUID CHEMICAL DEPOSITION PROCESS APPARATUS AND EMBODIMENTS”, (the '814 application) and U.S. Pat. No. 8,354,294 (the '294 application), de Rochemont, “MONOLITHIC DC/DC POWER MANAGEMENT MODULE WITH SURFACE FET”, U.S. Pat. No. 8,552,708 (the '708 application), de Rochemont, U.S. Pat. No. 8,749,054, “SEMICONDUCTOR CARRIER WITH VERTICAL POWER FET MODULE”, (the '054 application), de Rochemont U.S. Pat. No. 9,023,493, “CHEMICALLY COMPLEX ABLATIVE MAX-PHASE MATERIAL AND METHOD OF MANUFACTURE”, (the '493 application), de Rochemont U.S. Pat. Nos. 8,779,489 and 9,153,532, “POWER FET WITH A RESONANT TRANSISTOR GATE”, (the '489 and '532 application), de Rochemont U.S. Pat. No. 9,123,768, “SEMICONDUCTOR CHIP CARRIERS WITH MONOLITHICALLY INTEGRATED QUANTUM DOT DEVICES AND METHOD OF MANUFACTURE THEREOF”, (the '768 application), de Rochemont U.S. Pat. No. 8,952,858, “FREQUENCY-SELECTIVE DIPOLE ANTENNAS”, (the '858 application), de Rochemont and Kovacs U.S. Pat. No. 9,348,385, “HYBRID COMPUTING MODULE” (the '385 application), and, de Rochemont, “FULLY INTEGRATED THERMOELECTRIC DEVICES AND THEIR APPLICATION TO AEROSPACE DE-ICING SYSTEMS”, U.S. Application No. 61/529,302 ('302).
(3) The '698 application instructs on methods and embodiments that provide meta-material dielectrics, including artificial magnetic ground planes, that have dielectric inclusion(s) with performance values that remain stable as a function of operating temperature. This is achieved by controlling the dielectric inclusion(s)' microstructure to nanoscale dimensions less than or equal to 50 nm. de Rochemont '839 instructs the integration of passive components that hold performance values that remain stable with temperature in printed circuit boards, semiconductor chip packages, wafer-scale SoC die, and power management systems. de Rochemont '159 instructs on how LCD is applied to form passive filtering networks and quarter wave transformers in radio frequency or wireless applications that are integrated into a printed circuit board, ceramic package, or semiconductor component. de Rochemont '657 instructs methods to form an adaptive inductor coil that can be integrated into a printed circuit board, ceramic package, or semiconductor device. de Rochemont et al. '814 discloses the liquid chemical deposition (LCD) process and apparatus used to produce macroscopically large compositionally complex materials, that consist of a theoretically dense network of polycrystalline microstructures comprising uniformly distributed grains with maximum dimensions less than 50 nm. Complex materials are defined to include semiconductors, metals or super alloys, and metal oxide ceramics. de Rochemont '814 and '708 instruct on methods and embodiments related to a fully integrated low EMI, high power density inductor coil and/or high power density power management module. de Rochemont '489 and '532 instruct on methods to integrate a field effect transistor that switch arbitrarily large currents at arbitrarily high speeds with minimal On-resistance into a fully integrated silicon chip carrier. de Rochemont '768 instructs methods and embodiments to integrated semiconductor layers that produce a 3-dimensional electron gas within semiconductor chip carriers and monolithically integrated microelectronic modules. de Rochemont '302 instructs methods and embodiments to optimize thermoelectric device performance by integrating chemically complex semiconductor material having nanoscale microstructure. de Rochemont '858 instructs means to form a circuit resonant element by folding arms of dipole antenna or transmission line to induce inductive and capacitive loads through current vector coupling. The various embodiments and means claimed in the present application are constructed using liquid chemical deposition (LCD) methods instructed by de Rochemont et al. '814.
(4) LCD methods permit the integration of high chemical complexity electroceramics on a buried microelectronic layer with the requisite chemical precision to make the finished product economically viable. It enables chemically complex electroceramics to be selectively deposited on a semiconductor surface at temperatures that do not damage embedded active circuitry. It further enables the integration of chemically complex electroceramics with atomic scale chemical uniformity and uniform microstructure, including microstructure that has nanoscale uniformity irrespective of electroceramic chemical complexity.
(5) Reference is now made to
(6) The physical displacement 112 is not instantaneous. It will have a polarization time, τ.sub.polarization, which is a function of the electroceramics' chemistry. τ.sub.polarization will range between microsecond and nanosecond timescales. This phase delay introduces power loss and signal distortions to the electrical system. The physical displacement 112 also mechanically distorts the crystalline lattice that generates internal strain and will stress adjacent material layers with which the perovskite electroceramic is embedded within an integrated structure, such as the multilayer storage capacitor 100. This stress can cause thermomechanical fatigue within the component layers of the multilayer storage capacitor 100 over time. The long polarization times, τ.sub.polarization, also distort the phase of signals traveling through the dielectric as it becomes impossible to preserve signal integrity when the signal is modulated faster than the polarization (depolarization) time, τ.sub.polarization, of the dielectric. Dielectric materials having a polarization response time on the order of 1 μsec (10.sup.−6 seconds) would introduce phase distortions and associated power loss to signals operating above 1 MHz (10.sup.6 cycles per second). Similarly, dielectric materials having a polarization response time on the order of 1 nsec (10.sup.−9 seconds) would introduce phase distortions and associated power loss to signals operating above 1 GHz (10.sup.9 cycles per second). As will be shown in further detail below, these phase and power distortions to the higher order harmonic frequencies that form the pulse shape of clocking signals operating in the GHz frequency spectrum ultimately induce the ringing that cuts off higher speed system performance. This is a consideration for using titanium oxide (TiO.sub.2) layers in chip stack assemblies. It has moderately high relative permittivity, ε.sub.R=70, to improve impedance matching, but does not have mobile cations 106 that contribute slow (μsec to nsec) polarization response times, τ.sub.polarization.
(7)
(8) The physical displacement 112 of mobile cations 106 is generated by cooperative internal electric fields that are only strong enough to displace the mobile cations 106 and overcome the mechanical inertia that resists the deformation of the crystalline lattice 104 when the electroceramic grain size is greater than 50 nm. As explained below, a specific objective of the present invention minimizes signal distortion, power loss to embed high energy density dielectric layers 300 that comprise perovskite electroceramic having uniform grain chemistry and grain size less than 50 nm within a high speed semiconductor chip stack 200.
(9) As is self-evident from
(10) The basic stoichiometry of titanate perovskite electroceramics is given by the formula equation:
M.sup.(I).sub.(1−x−y−z)M.sup.(II).sub.(x)M.sup.(III).sub.(y)M.sup.(IV).sub.(z)Zr.sub.(1−a−b)Hf.sub.(b)Ti.sub.(a)O.sub.3 (1a)
where M.sup.(I), M.sup.(II), Mn.sup.(III), M.sup.(IV) are additional metal oxide components that form a thermodynamically stable perovskite crystal and x, y, and z, are fractional molar percentages forming ratios such that the sum of all M.sup.(I), M.sup.(II), Mn.sup.(III), M.sup.(IV) elemental components satisfies the constraint:
(1−x−y−z)+(x+y+z)=1 (1b)
And,
(1−a−b)+(a+b)=1 (1c)
The same general relationship for titanate (Ti-containing), zirconate (Zr-containing), hafnate (Hf-containing) electroceramics applies to niobate and tantalate electroceramics, which are implicitly claimed by the present invention. Crystal lattices with higher average amu is achieved by incorporating higher amu elements into the perovskite chemical formula. It is therefore a specific embodiment of the application to claim high energy density capacitive dielectric layers 300 that comprise a perovskite electroceramic that includes three or more metal oxide components that further comprise an admixture of three (3) or more of the elements listed in Table I.
(11) TABLE-US-00001 TABLE I Transition Metal Elements Symbol Sc Ti V Cr Mn Zn Zr Nb Mo Hf Ta W amu 21 22 41 42 25 30 40 41 42 72 73 74 Lanthanide Metal Elements Symbol La Ce Pr Nd Sm Eu Gd Tb Dy Ho Yb amu 57 58 59 60 62 63 64 64 66 67 70 Post Transition Metal Elements Symbol In Sn Pb Bi amu 49 50 82 83
(12) Reference is now made to
(13) As illustrated in
(14) As illustrated in
(15)
(16)
(17) By contrast, dielectric media comprising a microstructure that limit the polarization response 132A,132B to femtosecond time scales will have a polarization response representative of curve 131, which holds performance stable out close to the PetaHertz (PHz) frequency domain (10.sup.6 GHz). Impedance matching networks comprising dielectric media with this improved higher frequency performance improve the signal integrity of digital pulses operating above the intrinsic clock speeds of modern semiconductor die. The improved higher frequency signal integrity in chip stack assemblies driven higher clock speeds improves optical and wireless telecommunications signaling bandwidths. An aspect of this invention claims a high-speed semiconductor chip stack that operates with an operational system clock speed that optimally matches the intrinsic clock speed of the slowest semiconductor die in the chip stack. Additional embodiments of this invention include claims to a high speed semiconductor chip stack 200 that further comprises embedded semiconductor die 218 or 203 that function in an optical telecommunications or electro-optic capacity, or a component of a wireless transmitter, wireless receiver, or wireless transceiver circuit module.
(18) Reference is now made to
(19) The integration of ultra-low loss, high magnetic permeability (μ.sub.r≥10) magnetic cores within inductive elements 226 claimed by the application is a specific embodiment of the invention. Garnets are the preferred magnetic core material at GHz frequencies within a high speed semiconductor chip stack 200. Garnets adopt either rhombic dodecahedron or trapezohedron crystal structures, or a combination of the two, and have the following chemical formula:
A.sub.3B.sub.2(SiO.sub.4).sub.3 (2)
Where Group A metal oxides have equal molar concentration to silicon oxide and group B metal oxides have molar concentration that is % the molar concentration of silicon oxide. Group A metal oxides preferred for use in high permeability garnet electroceramics include: calcium oxide (CaO), magnesium oxide (MgO), iron oxide (FeO), and manganese oxide (MnO). Group B metal oxides preferred for use in high permeability garnet electroceramics include: aluminum oxide (Al.sub.2O.sub.3), iron oxide (Fe.sub.2O.sub.3), chromium oxide (Cr.sub.2O.sub.3), vanadium oxide (V.sub.2O.sub.3), zirconium oxide (ZrO.sub.2), titanium oxide (TiO.sub.2), silicon oxide (SiO.sub.2), yttrium oxide (Y.sub.2O.sub.3), cobalt oxide (Co.sub.3O.sub.4), gadolinium oxide (Gd.sub.2O.sub.3) neodymium oxide (Nd.sub.2O.sub.3) and holmium oxide (Ho.sub.2O.sub.3). Optimal compositions for high permeability garnet electroceramics comprise admixtures of Group A and/or Group B metal oxides. It is preferred embodiment of the present invention that the high permeability garnet magnetic cores 142 integrated in a high-speed semiconductor chip stack 200 have controlled microstructure with grain size ranging from 10 nm to 25 μm, preferably from 250 nm to 5 μm. Improved magnetic coupling can be achieved if the garnet magnetic core 142 further comprises an ultra-loss “air gap” material (not shown for clarity) in immediate contact with an inductive winding, preferably an amorphous silica air gap material integrated within the magnetic core using LCD methods. Eddy current power losses can be further reduced when the garnet magnetic core 142 further comprises one or more internal layers with layer thickness measuring 1-10 nm (not shown for clarity) of ultra-low loss material, preferably amorphous silica, within the magnetic core body.
(20) Reference is now made to
(21) The high-speed semiconductor chip stack 200 may also comprise a sidewall power plane 212 that electrically connects to a planar power plane on 213 the surface of any semiconductor die 208 or interposer 206 in the stack of wafer bonded chips 202. The grounding planes and power planes for any semiconductor die, interposer, or sensor chip may also be electrically connected internally within the chip stack through vias. The high-speed semiconductor chip stack 200 may also comprise a sidewall ground plane 214 that covers portions 216 of one or more sides of the high-speed semiconductor chip stack 200. It is a preferred embodiment of the application that the sidewall power plane 212 be located between two side sidewall ground planes 214 that are symmetrically placed adjacent to the sidewall power plane 212. The sidewall ground plane may also cover the entire side 217 of one or more sides of the high speed semiconductor chip stack 200. The sidewall ground plane 214 electrically connects to a planar ground plane 215 on the surface of any semiconductor die 208, sensor chip 207, or interposer 206 in the stack of wafer bonded chips 202. It is a preferred embodiment of the application that the planar power plane 213 be located between two side planar ground planes 215 that are symmetrically placed adjacent to the planar power plane 213. Ground planes may also be in electrical communication with grounding pads 219. Grounding pads 219 may make additional electrical contact with vias to route electrical ground to specific locations on other electrical layers within the high-speed semiconductor chip stack.
(22) The high-speed semiconductor chip stack 200 may optionally include surface bonded semiconductor die 218 that are die-to-wafer bonded to a major surface 220 of the high speed semiconductor chip stack 200. The surface bonded die are electrically connected to an array of contact pads 221 formed on or formed within the interposer 206 or semiconductor die 208 positioned at the top of chip stack 200. Furthermore, the surface mounted semiconductor die 218 may alternatively include a plurality of semiconductor die that are bonded as a stacked assembly, preferably as a high-speed semiconductor chip stack 200. The major surface 220 at the top of the chip stack may additionally include passive components fabricated using LCD methods that are formed on or bonded to the major surface 220. The passive components may comprise one or more decoupling, frequency filtering or tuning capacitive elements 222, resistors 224, and inductive elements 226. and are electrically interconnected to the high speed semiconductor chip stack through vias 204 or transmission lines 205 on the major surface. In general, these passive components will protrude from the major surface 220 at the top of the chip stack. It is a preferred embodiment that the capacitive elements 222 comprise one or more high energy density dielectric layers 300 wherein the average amu within the crystalline lattice 104 is greater than 25 amu, preferably greater than 50 amu, and the high energy density dielectric layer 300 comprises nanoscale microstructure 118 that fully polarizes and depolarizes with femtosecond response times. It is an additional preferred embodiment that the magnetic cores of the inductor coils 226 comprise a garnet electroceramic magnetic core 142. The resistive material in the resistor 224 may either comprise a metal, an alloy, superalloy or a resistive electroceramic.
(23) Reference is now made to
(24) Capacitive dielectrics are used as a temporary reservoir of stored electromagnetic energy. A simple capacitor will have store and release charge at a rate governed by its RC constant (internal resistance (R) x capacitance (C)), but the stored energy cannot be modulated faster than τ.sub.polarization even if the RC constant is less than τ.sub.polarization. In these instances, the slower polarization rates will introduce distortions and power loss to the modulated signal.
(25)
Q=CV (3a)
where C is the capacitance measured in Farads, and V is the applied voltage in Volts. The Capacitance, C, of a parallel plate capacitor is determined by the surface area, A, of the conductive electrodes 304A,304B, the distance, d, separating the conductive electrodes 304A,304B, and the dielectric permittivity (ε.sub.oε.sub.R) of the material 300 that fills the distance, d, between the conductive electrodes 304A,304B,
C=Aε.sub.oε.sub.R/d (3b)
where ε.sub.o is the permittivity of free space, and ε.sub.R is the relative permittivity of the dielectric material separating the two conductors. Relative permittivity sa functions as an electromagnetic lens that linearly magnifies the charge stored per unit area. Higher capacitance per unit area is achieved by forming multilayer capacitor 310 structures, wherein the capacitance of a single layer is added in parallel. Small profile size is achieved by forming a planar capacitor 404C.
(26) The inherent magnification associated with high energy density dielectrics 300 is useful in miniaturizing the feature size of characteristic circuit elements. A 3 GHz electromagnetic wave has a 1 cm wavelength, and a 30 GHz electromagnetic wave has a 1 mm wavelength. Maintaining signal integrity at elevated frequencies is highly dependent upon the use of resonating elements to properly terminate signal transmission lines. The magnification factor of high energy density dielectric layers 300 is useful in building resonating bodies that are useful in impedance matching structures and have small enough feature size to be packaged within a the confines of semiconductor chip stack 200 operating in the 7-20 GHz frequency range to improve signal integrity and signal termination.
(27) Reference is made to
(28) Reference is now made to
(29) Under the scope of the application, various means may be deployed as transmission lines used to make lateral electrical interconnections within a surface layer 402A,402B fabricated on the face of a die-mounted semiconductor die 208, sensor device 207 or interposer 206 As will be shown, surface layers are used to interface the major surface 220 of components embedded within a high-speed semiconductor chip stack 200. Microstrip 352 transmission line may be used in applications where ground shielding is not imperative. A microstrip transmission line 352, depicted in
(30) As illustrated in
(31) As represented in
(32)
(33) As presented in
(34) As illustrated in
(35) A second embodiment 384B of the meta-material dielectric core 384 within a dielectric waveguide 359 comprises a host dielectric 336 further comprising a periodic array of dielectric inclusions 387 that may comprise high energy density dielectric 300 or garnet magnetic core 142 material. The principal objective for these structures is to create conditions for a resonant standing wave along the length of the meta-material dielectric waveguide that is critically dampened at a terminating via 404E.
(36) The application of meta-material dielectric cores 384 that periodically alternate garnet magnetic cores 142 and high energy density dielectric 300 or comprise dielectric inclusions 387 along the length of the dielectric waveguide 359 is also a preferred embodiment for the dielectric cores in stripline 354, microstrip 352, stripline 354, ground-cladded stripline 357, ground-cladded dielectric waveguide 355, and a dielectric slab waveguide 359.
(37) The inclusion of high energy density dielectric 300 as layers or inclusions layers within high speed semiconductor chip stacks 200 provides multiple functionalities that serve the purpose of the present invention. First, they enable the construction of transmission lines that have low characteristic impedance Z.sub.o, which is given by:
(38)
(39) Therefore it is advantageous to construct transmission lines or a surface feature comprising high energy density capacitive dielectric layers 350 that have maximal relative permittivity, ε.sub.R, to improve impedance matching with low impedance input and output ports on semiconductor die within the high-speed semiconductor chip stack 200 in the system. Similarly, it is advantageous to construct transmission lines or a surface feature comprising high relative permeability, pa, ultra-low loss garnets 142 when matching the lines to high impedance ports in the system.
(40) As noted above, high energy density dielectrics 300 reduce characteristic feature size of transmission line and resonating bodies used to match impedance and terminate electrical connections. Characteristic feature size scales with electromagnetic wavelength, λ.sub.o, and the guided wavelength, λ.sub.g, when the electromagnetic wave is propagating through a dielectric medium. Guided wavelength, λ.sub.g, is reduced in proportion to relative permittivity, ε.sub.R, as
λ.sub.g=λo/√{square root over (ε.sub.R)} (4b)
(41) In a free-space vacuum, where ε.sub.R=1, a 10 GHz signal has an electromagnetic wavelength of 30 mm, and a 20 GHz signal has an electromagnetic wavelength of 15 mm, which represent feature sizes that would be difficult to accommodate within the physical dimensions of a chip stack 1,200. However, within the body of a high energy density dielectric 300 having a high ε.sub.R or a garnet magnetic core with magnetic permeability μ.sub.R>>1, the guided wavelength λ.sub.g is reduced as:
λ.sub.g=λ.sub.o/√{square root over (μ.sub.Rε.sub.R)} (4c)
(42) Therefore, within a high energy density dielectric 300 having μ.sub.R=1 and ε.sub.R=400 the guided wavelength λ.sub.g and characteristic feature of elements and resonating bodies that serve as termination components is reduced by 20×. Thus, a 10 GHz signal would have a guided electromagnetic wavelength of 1.5 mm, and a 20 GHz signal has an electromagnetic wavelength of 0.75 mm. Similarly, within a high energy density dielectric 300 having μ.sub.R=1 and ε.sub.R=800 the guided wavelength λg and characteristic feature of elements and resonating bodies that serve as termination components is reduced by 28×. Thus, a 10 GHz signal would have a guided electromagnetic wavelength of ≈1.1 mm, and a 20 GHz signal has a guided electromagnetic wavelength of ≈0.5 mm. These physical dimensions are more compatibly integrated within the confines of stacked chip assemblies and are well within the photo-patterning tolerances of modern microelectronic manufacturing.
(43) Reduced feature sizes proportionally reduce the size requirements of strip line 354, waveguide 355, and ground-cladded striplines 357. Waveguide 355 and ground-cladded striplines 357 are preferred embodiments as surface features for making electrical connections because their TM.sub.o mode has no cut-off frequency and will transmit power with attenuation limited to loss in the high energy density dielectric 300 as long as the characteristic dimensions h,w are at least half of the guided wavelength, h,w≥0.5λ.sub.g.
(44) Phase velocities, υ.sub.p are proportionally reduced as:
υ.sub.p=c/√{square root over (μ.sub.Rε.sub.R)} (4d)
where c is the speed of light in a vacuum. The slower υ.sub.p will increase latency, but that will be offset by the shorter physical distances that separate microprocessor and memory components within a high speed semiconductor chip stack 200. As discussed below, lower phase velocity will increase the need for impedance matching terminations in the circuit. However, information, whether composed as a digital pulse or a modulated analog signal, is composed of a fundamental frequency (or clock speed) and a Fourier series of higher order harmonics that shape the pulse or encode the information as a modulated signal. The dispersion characteristics of the transmission medium define the variance in the propagation of higher and lower order frequencies in the Fourier series as a function of distance. Dispersion is a function of the frequency (ω) dependence of the dielectric constant μ.sub.oμ.sub.R(ω)ε.sub.oε.sub.R(ω). Dielectric dispersion causes a well-defined pulse to become distorted over longer propagation paths as some frequencies in the Fourier series have higher propagation velocities than others. Dispersion is most pronounced around a resonance within the dielectric medium that is determined by the polarization response time, τ.sub.polarization. The femtosecond polarization response times of the high energy density dielectrics 300 pushes the resonance to terahertz (THz) frequencies, minimizing distortion in the transmission of modulated signals in the 10-20 GHz frequency range. The use of low dispersion dielectrics will also facilitate impedance matching in the system as the entire group of encoded frequencies can be considered to have similar propagation characteristics.
(45) In high speed digital design, electrical length, l, is a characteristic of electromagnetic wave propagation along a transmission line that becomes an important design consideration as it determines the dimensions over which a circuit can be designed as a lumped circuit or needs to be designed as a distributed network. Electrical length l is determined by the rise time T.sub.r (in picoseconds) of the leading edge of a digital pulse and the delay (D) in the transmission line, measured in picoseconds per inch as determined by the phase velocity up, incurred as the digital pulse transitions binary states at the receiving port.
l=T.sub.r/D (4d)
As a general rule, any transmission line longer than l/6 will have to be designed as a distributed network having consistent impedance per unit length with proper termination to avoid ringing. As shown in Table II, the introduction of high energy density capacitive dielectric materials substantially shortens the distances over which a high speed semiconductor chip stack 200 can be designed as a lumped circuit
(46) TABLE-US-00002 TABLE II rising edge lumped circuit lumped circuit Material Dielectric Constant Delay (ps/in) length (in) length (in) length (mm) Rise Time (ps) 1,000 air 1 85 11.76 1.96 49.80 FR4 4.5 180.31 5.55 0.92 23.48 alumina 10 268.79 3.72 0.62 15.75 titania 70 711.16 1.41 0.23 5.95 HEDCD-1 200 1202.08 0.83 0.14 3.52 HEDCD-1 800 2404.16 0.42 0.07 1.76 Rise Time (ps) 100 air 1 85 1.18 0.20 4.98 FR4 4.5 180.31 0.55 0.09 2.35 alumina 10 268.79 0.37 0.06 1.57 titania 70 711.16 0.14 0.02 0.60 HEDCD-1 200 1202.08 0.08 0.01 0.35 HEDCD-1 800 2404.16 0.04 0.01 0.18
(47) Reference in now made to
(48) Unconventional means are required to electrically interconnect connect ground-cladded dielectric waveguide 355, and a dielectric slab waveguide 359 to other components in the chip stack.
(49)
(50) A principal objective of the present application aims to mitigate conductive power loss in metal traces at higher frequencies. Eliminating conductive power losses is desirable to reduce thermal loads and the additional costs of thermal management systems. The reduced dielectric loss and faster polarization response times coupled to the feature size reduction enabled by high energy density dielectric 300 favors the use of waveguides over conductive traces in high-speed semiconductor chip stacks.
(51) All antenna arrays 394 can be highly directional. An antenna array 394, using an End Fire antenna array as an example, is depicted in
(52) In the case of an End Fire antenna array, the radiating bodies 396A,396B,396C, 396D,396E,396A′,396B′,396C′,396D′,396E′ comprise half-wavelength dipole elements that are separated by a distance of a quarter of the guided wavelength (0.25λ.sub.g) and the phasing system 397 is designed to phase delay the signal by 90° between the individual radiating bodies 396A,396B,396C,396D,396E,396A′,396B′,396C′,396D′,396E′. This causes the phase delayed feed/return signals to constructively interfere with the radiated signals from each of the emitting dipole elements. This constructive interference is primarily directed off of the last radiating bodies 396E,396E′ in the array and down the waveguide in a focused beam. It is a preferred embodiment of the invention to situate the first radiating bodies 396A,396A′ in the array an optimal distance 398 from the back ground pad sidewall 219C. This distance is determined by the guided wavelength, λ.sub.g, and varies for a given antenna array configuration. In the case of the End Fire antenna array, a quarter of the guided wavelength (0.25λ.sub.g) from the back ground pad sidewall 219C maximizes the power radiated down the waveguide. The radiating bodies 396A,396B,396C,396D,396E,396A′,396B′,396C′,396D′,396E′ need not be linear bodies as depicted FIG. M thru FIG. O. They may be electrically small and comprise folded geometry elements 399 that impart frequency-selectivity and added directional gain, as instructed by de Rochemont '858 incorporated herein by reference. The folded geometry elements 399 may extend the radiating bodies to have features that exist on more than one plane.
(53) The feed network 395 of antenna arrays 394 may comprise a single input via 204 but will optimally comprise two vias 204, which may be thru vias 204A or single layer vias 204B. One via in the feed network 395 feeds a source signal to half of the individual radiating bodies 396A,396B,396C,396D,396E. The other draws a return signal from the individual radiating bodies 396A′,396B′,396C′,396D′,396E′. In higher fidelity applications, the feed network 395A will route the source and return signals through vias 204 to circuitry on other layers. In applications with less stringent performance specifications, the feed network 395B will route the source signals through vias 204 to circuitry on other layers, while the return signal will make contact with the lower ground plane layer 395B. Antenna arrays 394, radiating bodies 396, and folded geometry elements 399 may further comprise closely coupled director elements 390 that may comprise a conducting body, a dielectric, or a high energy density dielectric 300.
(54) While these unconventional means are developed for dielectric waveguides they are universally applicable to all transmission lines in this application.
(55) Reference is now made to
(56) Planar surface features 404A,404B,404C,404D are integrated into surface layers 400A,400B that conjoin at the interfacial boundaries 402 between stacked components (semiconductor die 202, sensor chips, and interposers) and surface bonded die 218 within a high speed semiconductor chip stack 200. The surface layers 400A,400B comprise dielectric cores 351, which is not shown in
(57) Surface features 404A,404B,404C,404D are specifically integrated into surface layers 400A,400B to function as distributed capacitance or inductance along transmission lines or impedance matching elements that electrically terminate electrical interconnections within the surface layers 400A,400B, or between vias 204. Vias 204 may be a single layer via 204A that terminates in a surface layer 400A,400B or a thru via 204B that electrically connects wafer bonded chips 202 within the high-speed semiconductor chip stack 200 when surface layers 400A,400B are conjoined at the interfacial boundaries 402. Thru vias 204B are also found at the interface between a stack of wafer-bonded chips 202 and surface-mounted semiconductor die 218. These surface features are embedded within the dielectric core 351, which is not shown in
(58) A surface feature may comprise an electrical short 404A that may comprise any of the transmission line structures depicted in
(59) As depicted in
(60) As depicted in
(61) As illustrated in
(62) Impedances are most frequently mismatched at physical discontinuities within a transmission line, such as a bend, gap, or change in the physical dimensions of the transmission line's conducting element. Impedance mismatching is most prevalent at vias, whether they are thru vias or simply a vertical connection to an adjacent layer in the 3D circuit construction. Impedance matching is also required to electrically connect signals traveling in low permittivity (ε.sub.R) dielectric media that is used in the electrical interconnect structures of semiconductor die 208 to the high energy density capacitive dielectrics 350 that are incorporated in the surface layers 402A,402B formed on the interposers 206, sensor chips 207, and semiconductor die 208,218 that are bonded into the high speed semiconductor chip stack 200. In view of these technical considerations, means that provide impedance matching at a via 204 or via pad 405 is an essential element of the present application.
(63) Reference is now made to
(64)
(65)
(66)
(67) Reference is now made to
(68) As depicted in
(69) In order to constitute high quality sidewall contact within the gaps 610,616 and around the serpentine conducting element 602, it is recommended that the LCD deposits overspray the targeted region. This forms protruding material 630 that is selectively deposited on top of the base conductive element that is removed by chemical mechanical polishing techniques to restore a smooth surface 632 to the surface features 622,626,628. (See
(70) LCD methods are used to selectively deposit non-planar features in the surface layer that give it unique function, such as thru vias, antenna stubs, and antenna arrays.
(71) LCD methods and chemical mechanical polishing are used to apply transmissions lines 205, dielectrics, and embed the surface features 404A,404B,404C,404D. A bonding layer 640 is applied to the dielectric core 351 forming the surface layer 400A as a final encapsulation step. (See
(72) Chip stack bonding may be achieved in a variety of ways. A preferred method utilizes oxide-oxide low-temperature direct bonding techniques that are commonly used in 3D wafer and chip integration, wherein oxide material deposited on the surface of the chips is used as the bonding agent. Metal-metal low temperature direct bonding techniques are also applicable at surface areas where exposed metal configured to provide a mating surface and electrical interface between chips are available.
(73) Reference is now made to
(74) Cryptocurrencies, such as Bitcoin are mined using a complex computer algorithm and maintained on a Blockchain. At the time of this filing, approximately 16 million of the 21 million total minable bitcoin have been mined. Bitcoin mining requires intense computational power. It is anticipated that the 5 million Bitcoin remaining will require 100 years to be mined using computer systems operating at contemporary clock speeds. Clock speed sets the rate at which an algorithm can run. A chip stack computing module that increases the operational clock speed of all the chips in a stack from the current standard of 7-7.5 GHz to an operational clock speed closer to the intrinsic 220 GHz clock speeds of the semiconductor die embedded within the chip stack will process an algorithm approximately 3× faster. These faster clock speeds will allow the remaining 5 million available Bitcoin to be mined in 33 years rather than 100 years. This higher efficiency represents substantial economic value.
(75) Therefore, a further embodiment of the invention claims high speed semiconductor chip stacks 700A,700B that comprise other chips 702A,702B that function as an ASIC chip specifically designed to process algorithms that mine Bitcoin. While these high speed semiconductor chip stacks 700A,700B could be mounted on a printed circuit board, an additional further embodiment claims a multi-chip module 705 that comprises high speed semiconductor chip stacks 700A,700B further comprising other (ASIC) chips 702A,702B designed to process algorithms that mine Bitcoin that are mounted on a fully integrated semiconductor chip carrier 704.
(76) An additional embodiment includes one or more thermoelectric devices comprising a 3D quantum gas layer mounted on the multi-chip module or embedded in high speed semiconductor chip stacks 700A,700B that are used to pump heat from a CPU to a thermal reservoir, wherein the thermal reservoir may comprise a second thermoelectric device comprising a 3D quantum gas layer that is used to convert the transferred heat back into power that is, in turn, supplied back to the circuit.