US3909305A - Ion implantation process - Google Patents

Ion implantation process Download PDF

Info

Publication number
US3909305A
US3909305A US358072A US35807273A US3909305A US 3909305 A US3909305 A US 3909305A US 358072 A US358072 A US 358072A US 35807273 A US35807273 A US 35807273A US 3909305 A US3909305 A US 3909305A
Authority
US
United States
Prior art keywords
ion
ions
ion source
predetermined
mass separator
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US358072A
Other languages
English (en)
Inventor
Hartmut Boroffka
Eberhard Krimmel
Hartmut Runge
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Application granted granted Critical
Publication of US3909305A publication Critical patent/US3909305A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/30—Electron-beam or ion-beam tubes for localised treatment of objects
    • H01J37/317—Electron-beam or ion-beam tubes for localised treatment of objects for changing properties of the objects or for applying thin layers thereon, e.g. for ion implantation
    • H01J37/3171—Electron-beam or ion-beam tubes for localised treatment of objects for changing properties of the objects or for applying thin layers thereon, e.g. for ion implantation for ion implantation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S438/00—Semiconductor device manufacturing: process
    • Y10S438/961—Ion beam source and generation

Definitions

  • ABSTRACT A technique for simplifying ion implantation so that a plurality of different ions may be implanted in a single object without long periods of time between implantations.
  • the technique utilizes, in a given ion source, a select initial substance to be ionized which initial substance contains all of the ions to be implanted. Then during the subsequent implantation procedure the ions are either simultaneously or sequentially implanted into the object.
  • the process in accordance with the invention may be advantageously applied also when individual implantations with different types of ions are to be effected in consecutively implanted objects.
  • An aim of the invention is to provide a process for ion implantation with the aid of which an object being implanted with ions can, without a time consuming change of ion source, be subjected in relatively rapid succession to ions of various types, and/or can be simultaneously subjected to ions of two or more types.
  • An advantage of the process of the invention is that the long periods of time heretofore required by the prior art for changing from one ion type or source to another may be reduced to changeover times which may be as brief as a few seconds.
  • Another advantage of the process of this invention results where an ion implantation is effected in objects which are maintained at high temperatures because, by the present process, in contrast to the processes of the prior art, objects at high temperatures can be implanted with different types of ions in rapid succession before the profile of a type of ion already implanted in the object changes.
  • FIG. 1 is a schematic, diagrammatic view of the class of ion implantation apparatus useful in the practice of the process of the present invention
  • FIG. 2 is a vertical, sectional, schematic, detailed view of one type of ion source useful in the apparatus of FIG. 1;
  • FIG. 3 is a simplified, partially diagrammatic view in side elevation of one embodiment of apparatus used to practice the process of the present invention
  • FIG. 4 is a view similar to FIG. 3, but showing a top plan view of such apparatus
  • FIG. 5 shows a mass spectrum plot of an ion emission stream produced in accordance with the teachings of this invention derived from the compound B P as the initial substance;
  • FIG. 6 shows a mass spectrum plot of an ion emission stream produced in accordance with the teachings of this invention derived from a mixture of amorphous B (boron) and amorphous P (phosphorous) as the initial substance; and
  • FIG. 7 shows a mass spectrum plot of an ion emission stream produced in accordance with the teachings of this invention derived from a mixture of BCL, and PCI as the initial substance.
  • an ion source is supplied with an initial substance which (may be in the form of an alloy) containing all the elements to be ionized which are necessary for an ion implantation, and such initial substance is chosen so that the various, required types of ions desired for an implantation are produced either simultaneously or sequentially.
  • an initial substance which (may be in the form of an alloy) containing all the elements to be ionized which are necessary for an ion implantation, and such initial substance is chosen so that the various, required types of ions desired for an implantation are produced either simultaneously or sequentially.
  • initial substance preferably takes place in dependence upon the type of ion source used in any given instance, in which connection, for example, the vapor pressure, the ionization energy, the dissociation energy, and/or the nature of the bond of the initial substance must be taken into account.
  • initial substances preferably comprise a plurality of chemical compounds which may or may not form addition compounds or the like.
  • the process of this invention utilizes an ion implantation unit comprising of an ion source, an extraction element, a mass separator, a focusing device, and an object holder, as those skilled in the art will appreciate.
  • an ion source 1 of an ion implantation unit which source 1 is supplied with the initial substance.
  • this initial substance comprises a mixture of chemical compounds which contain the various types of ions necessary for a desired implantation of an object secured in the object holder 13.
  • the initial substance comprises alloys, I or mixtures of different compounds which are ionizable to the ions desired in a given situation.
  • the ion source 1 is adapted to the state of matter of the initial substance.
  • ion sources include, for example, the duoplasmatron type with or without furnace, arc sources, high frequency sources, Penning sources, sputtering sources, and the like.
  • FIG. 2 is schematically shown an ion source of the duoplasmatron type, for present illustrative purposes.
  • This ion source utilizes a stage 14 wherein electrons and Helium-ions are produced in a helium plasma. These electrons ionize vapors in the expansion chamber 15. Vapors in expansion chamber 15 are produced by the vaporization of solid bodies of an initial substance in the furnace 16. If the initial substance is in a gaseous form at room temperature, such gaseous initial substance is admitted into the expansion chamber 15 via valve 17.
  • Mass separator 7 may be, and preferably is, for examples, a deflecting magnet, a Wien filter, or the like.
  • the mass separator may be, for example, a so-called resonance analyser, such as a quadrupole analyser.
  • the resolving power of the mass separator 7 is selected to be such that substantially only ions of one type pass through the outlet gap 9 of the mass separator 7. Ions of one type which leave the gap 9 of the mass separator 7 hit an object secured in the object holder 13 so that ion implantation of such object is accomplished.
  • ions of one type which leave the outlet gap 9 are post accelerated by the field of a post accelerator which follows the mass separator 7.
  • a post acceleration unit is referenced by the numeral 11.
  • ion optical elements used in an ion implantation unit adapted for use in practicing the process of the present invention may be arranged in any convenient sequence, as desired.
  • the mass separator 7 takes the form, for example, of a resonance analyser, and this resonance analyser is operated at higher modes.
  • the power supply of the ion source 1 is marked 2; the power supply of the extraction element 3 is marked 4; the power supply for the focussing device 5 is marked 6; the power supply for the mass separator 7 is marked 8; and the power supply for the post acceleration unit 11 is marked 10.
  • a process control unit 12 is preferably connected to all the current and voltage supplies.
  • Selection of a desired ion type from the sum of the ions of various types produced in the ion source 1 takes place by means of mass separation in the mass separator 7.
  • the change-over from one ion type to another is achieved by changing the fields used in the mass separator 7.
  • the field of a quadrupole analyser, or of a Wien filter may be changed in fractions of a second either manually, or in semi-automatic process controlled fashion, as desired.
  • the process of the present invention may be employed for the implantation of a complicated doping profile such as, for example, may occur in the manufac- I
  • a first step one charges said ion source with a composition comprising at least one vaporizable compound containing all elements types to be ionized and implanted.
  • so-passed ions as a beam against a predetermined said target object at a predetermined energy and in a predetermined profile.
  • the present invention is illustrated with boron and phosphorous because at present, these are the most widely used dopants in silicon, but those skilled in the art will appreciate that the present invention may be used widely.
  • the present invention may be practiced with the compound BP and is at present most preferably practiced with BC];
  • PCl Most preferably, these compounds are used at the rate of one part BCl to ten parts PCl Several additional advantages of using BCl PCl as a starting substance for B or P ion production should be mentioned:
  • the vapor pressure of BCl PCl at room temperature is less than 1 bar, so that the substance does not need to be stored in melted off glass containers.
  • the addition compound BCl PCl is much less aggressive than, for example, BCl alone.
  • the vacuum system of the ion implantation unit does not need recovery time after having stopped the BCl PCl input to the ion source in contrast to the application of a simple compound such as BCl where vacuum system recovery times of from about 2 to 3 hours are normal.
  • the B and P ion currents are stable after setting the suitable pressure in the ion source without any further change of the adjustment parameters of the ion source.
  • the heating power of the oven of an ion source has to be controlled permanently.
  • Embodiments demonstrate that the ion implantation process of this invention speeds up the feeding of the ion source with the proper starting substances.
  • the results were obtained using a duoplasmatron ion source, but those skilled in the art will appreciate that other ion sources will give other specific results yet will not change the main feature of the invention described herein.
  • Example A The ion implantation system used here is shown in FIGS. 3 and 4 and is comprised of an ion source 30 of the duoplasmatron type which is equipped with a 15 k V extraction element 31.
  • An electrostatic lens 32 focuses the ion beam (not shown) on the exit aperture 33 of the magnetic mass-separator 34.
  • the accelerator 36 provides means for imparting additional acceleration to ions between acceleration potentials ranging from to 300 k V.
  • the electrostatic quadrupole lens system 37 focuses the ion beam onto an object or specimen 38 located in the target chamber 39.
  • the x, y-scanning system 40 sweeps the ion beam over object 38 to produce uniform irradiation over the whole object 38.
  • the chamber 41 serves as an airlock for target chamber 39.
  • a set of specimens can be preevacuated in the airlock chamber 41 before being moved individually or .in groups into target chamber 39.
  • the valves 4-2 separate different sections of the system from one another.
  • the diffusion pumps 43 and the turbomolecular pumps 44 evacuate the system.
  • An ultra high vacuum technique is used which provides that residual gas pressure, neutral beam contamination of objects (or specimens) being implanted, and X-ray emission are maintained at low levels. In the following Examples, all ions are accelerated to an energy of 15 kc V.
  • EXAMPLE 1 Using the foregoing apparatus, BP as the initial substance is heated to above about 800C. in the oven of the ion source 30 to obtain a vapor pressure of about X Pa in the ion source. At equilibrium, a low but constant B,,* ion current of about 0.75 ,u.A and a higher P ion current of about 4AA (microamperes) is observed. As shown in FIG. 5, the mass spectrum shows peaks of B and P with a strong contribution of impurities as a result to the high oven temperature. During the initial use of the oven temperature, a very strong F" peak is observed which is reduced after equilibrium conditions are obtained. The target object is found to be implanted with both 1 and 8 ions subsequently.
  • EXAMPLE 2 Using the foregoing apparatus, of Example A, a mixture of B and P as the initial substance is heated to above about 200 C. in the oven of the ion source 30, it is found that a homogeneous mixture of amorphous l3 and amorphous P does not deliver B as long as the temperature in the oven does not exceed temperatures which limit seriously the life time of the duoplasmatron pressure of about 5 X10 Pa in the ion source. After pilot tests with BCl and with PCl the ion source is fed with a mixture of one part PCI;, and ten parts PCl resulting in an addition compound, BCI PCI As FIG. 7 shows, the mass spectrum shows E f and P ion currents of almost the same strength of approximately 4,uA.
  • the ion currents are stable and mainly easier and better reproducible to adjust than supplying the ion source only with the component compounds which is utilized for the implantation to be done in this time (see Example 2).
  • the target object is found to be implanted with both P and B ions subsequently. Using this procedure, multiple implantations with B and P are thus performed in by changing only the exciting current of the magnet of the mass separator 34, a procedure which need not consume more time than approximately 30 seconds. Hence, the excessive exchange times of dopants of the prior art are overcome.
  • EXAMPLE 4 ll In a process for ion implantation with an ion implantation unit in which said unit comprises an ion source, an extraction element, a mass separator, a focussing device and an object holder, the improvement which comprises the steps of charging to said ion source a composition comprising chemical compounds which contains all the elements to be ionized which are required for the desired implantation, said composition being adapted to produce all required ion types in said ion source either simultaneously or sequentially, and directing said ions so produced from such ion source as a beam along one beam path towards a target object, the ions in said beam being controlled by said mass separator so that a particular type or types of ions desired ion source used here. As shown in FIG.
  • composition consists of a mixture of at least two compounds.
  • a process for ion implantation of a target object using an ion implantation unit which comprises an ion source, an extraction element, a mass separator, a focussing device, and an object holder, said process comprising the steps of A. charging said ion source with a composition comprising at least one vaporizable compound containing all elements types to be ionized and implanted,
  • composition comprises a mixture of BCl and PC];;.
  • composition comprises the compound GaAs.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Physical Vapour Deposition (AREA)
  • Particle Accelerators (AREA)
  • Welding Or Cutting Using Electron Beams (AREA)
  • Electron Sources, Ion Sources (AREA)
US358072A 1972-05-09 1973-05-07 Ion implantation process Expired - Lifetime US3909305A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19722222736 DE2222736A1 (de) 1972-05-09 1972-05-09 Verfahren zur ionenimplantation

Publications (1)

Publication Number Publication Date
US3909305A true US3909305A (en) 1975-09-30

Family

ID=5844509

Family Applications (1)

Application Number Title Priority Date Filing Date
US358072A Expired - Lifetime US3909305A (en) 1972-05-09 1973-05-07 Ion implantation process

Country Status (10)

Country Link
US (1) US3909305A (fi)
JP (1) JPS4962076A (fi)
BE (1) BE799319A (fi)
CA (1) CA1011228A (fi)
CH (1) CH578891A5 (fi)
DE (1) DE2222736A1 (fi)
FR (1) FR2183853B1 (fi)
IT (1) IT987106B (fi)
LU (1) LU67556A1 (fi)
NL (1) NL7306419A (fi)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4179312A (en) * 1977-12-08 1979-12-18 International Business Machines Corporation Formation of epitaxial layers doped with conductivity-determining impurities by ion deposition
DE2835121A1 (de) * 1978-08-10 1980-02-14 Fraunhofer Ges Forschung Verfahren und vorrichtung zum dotieren von halbleitern mittels ionenimplantation
WO1986006875A1 (en) * 1985-05-17 1986-11-20 J.C. Schumacher Company Ion implant using alkali or alkaline earth metal tetrafluoroborate as boron ion source
US4721683A (en) * 1987-05-21 1988-01-26 American Cyanamid Company Use of alkylphosphines and alkylarsines in ion implantation
US5063294A (en) * 1989-05-17 1991-11-05 Kabushiki Kaisha Kobe Seiko Sho Converged ion beam apparatus
US5349196A (en) * 1992-04-10 1994-09-20 Hitachi, Ltd. Ion implanting apparatus
US5837568A (en) * 1995-12-12 1998-11-17 Sanyo Electric Co., Ltd. Manufacturing method of semiconductor devices
US6521506B1 (en) 2001-12-13 2003-02-18 International Business Machines Corporation Varactors for CMOS and BiCMOS technologies
US20070120075A1 (en) * 2005-11-30 2007-05-31 Axcelis Technologies, Inc. Beam current stabilization utilizing gas feed control loop

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1982004351A1 (en) * 1981-05-26 1982-12-09 Aircraft Co Hughes Focused ion beam microfabrication column

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3437734A (en) * 1966-06-21 1969-04-08 Isofilm Intern Apparatus and method for effecting the restructuring of materials
US3442725A (en) * 1966-05-05 1969-05-06 Motorola Inc Phosphorus diffusion system
US3477887A (en) * 1966-07-01 1969-11-11 Motorola Inc Gaseous diffusion method
US3484313A (en) * 1965-03-25 1969-12-16 Hitachi Ltd Method of manufacturing semiconductor devices
US3547074A (en) * 1967-04-13 1970-12-15 Block Engineering Apparatus for forming microelements
US3558376A (en) * 1966-01-07 1971-01-26 Siemens Ag Method for controlled doping by gas of foreign substance into semiconductor materials
US3737346A (en) * 1971-07-01 1973-06-05 Bell Telephone Labor Inc Semiconductor device fabrication using combination of energy beams for masking and impurity doping

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3484313A (en) * 1965-03-25 1969-12-16 Hitachi Ltd Method of manufacturing semiconductor devices
US3558376A (en) * 1966-01-07 1971-01-26 Siemens Ag Method for controlled doping by gas of foreign substance into semiconductor materials
US3442725A (en) * 1966-05-05 1969-05-06 Motorola Inc Phosphorus diffusion system
US3437734A (en) * 1966-06-21 1969-04-08 Isofilm Intern Apparatus and method for effecting the restructuring of materials
US3477887A (en) * 1966-07-01 1969-11-11 Motorola Inc Gaseous diffusion method
US3547074A (en) * 1967-04-13 1970-12-15 Block Engineering Apparatus for forming microelements
US3737346A (en) * 1971-07-01 1973-06-05 Bell Telephone Labor Inc Semiconductor device fabrication using combination of energy beams for masking and impurity doping

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4179312A (en) * 1977-12-08 1979-12-18 International Business Machines Corporation Formation of epitaxial layers doped with conductivity-determining impurities by ion deposition
DE2835121A1 (de) * 1978-08-10 1980-02-14 Fraunhofer Ges Forschung Verfahren und vorrichtung zum dotieren von halbleitern mittels ionenimplantation
WO1986006875A1 (en) * 1985-05-17 1986-11-20 J.C. Schumacher Company Ion implant using alkali or alkaline earth metal tetrafluoroborate as boron ion source
US4721683A (en) * 1987-05-21 1988-01-26 American Cyanamid Company Use of alkylphosphines and alkylarsines in ion implantation
US5063294A (en) * 1989-05-17 1991-11-05 Kabushiki Kaisha Kobe Seiko Sho Converged ion beam apparatus
US5349196A (en) * 1992-04-10 1994-09-20 Hitachi, Ltd. Ion implanting apparatus
US5837568A (en) * 1995-12-12 1998-11-17 Sanyo Electric Co., Ltd. Manufacturing method of semiconductor devices
US6521506B1 (en) 2001-12-13 2003-02-18 International Business Machines Corporation Varactors for CMOS and BiCMOS technologies
US20030122128A1 (en) * 2001-12-13 2003-07-03 International Business Machines Corporation Novel varactors for CMOS and BiCMOS technologies
US6891251B2 (en) 2001-12-13 2005-05-10 International Business Machines Corporation Varactors for CMOS and BiCMOS technologies
US20050245038A1 (en) * 2001-12-13 2005-11-03 International Business Machines Corporation Novel varactors for CMOS and BiCMOS technologies
US7135375B2 (en) 2001-12-13 2006-11-14 International Business Machines Corporation Varactors for CMOS and BiCMOS technologies
US20070120075A1 (en) * 2005-11-30 2007-05-31 Axcelis Technologies, Inc. Beam current stabilization utilizing gas feed control loop
WO2007064507A1 (en) * 2005-11-30 2007-06-07 Axcelis Technologies, Inc. Beam current stabilization utilizing gas feed control loop
US7361915B2 (en) 2005-11-30 2008-04-22 Axcelis Technologies, Inc. Beam current stabilization utilizing gas feed control loop

Also Published As

Publication number Publication date
CH578891A5 (fi) 1976-08-31
BE799319A (fr) 1973-08-31
LU67556A1 (fi) 1973-07-13
DE2222736A1 (de) 1973-11-22
JPS4962076A (fi) 1974-06-15
CA1011228A (en) 1977-05-31
FR2183853A1 (fi) 1973-12-21
NL7306419A (fi) 1973-11-13
FR2183853B1 (fi) 1977-02-11
IT987106B (it) 1975-02-20

Similar Documents

Publication Publication Date Title
US6130436A (en) Acceleration and analysis architecture for ion implanter
US5517084A (en) Selective ion source
US5300891A (en) Ion accelerator
US5313067A (en) Ion processing apparatus including plasma ion source and mass spectrometer for ion deposition, ion implantation, or isotope separation
Ravn Status and future development of ion sources for on-line mass separators
US3909305A (en) Ion implantation process
US3845312A (en) Particle accelerator producing a uniformly expanded particle beam of uniform cross-sectioned density
US4737688A (en) Wide area source of multiply ionized atomic or molecular species
US3955091A (en) Method and apparatus for extracting well-formed, high current ion beams from a plasma source
US7223984B2 (en) Helium ion generation method and apparatus
JP3523313B2 (ja) イオン注入システムに用いられる低エネルギによる大電流ビームの発生
Rahman Ion sources for use in research and low energy accelerators
US4881010A (en) Ion implantation method and apparatus
EP0995214B1 (en) Method and apparatus for neutralising space charge in an ion beam
KR100565814B1 (ko) 이온주입장치 및 그 운전방법
Walther et al. Production of atomic nitrogen ion beams
KR100289668B1 (ko) 이온주입장치
Batalin et al. Report on ITEP MEVVA development
WO2003044837A2 (en) Ion imlantation method and apparatus
JPH04124267A (ja) イオン注入装置
Grime et al. An ion accelerator facility for the preparation of nuclear bombardment targets
JPH08241687A (ja) Ｅｃｒ型イオン源
Wolf et al. Mevva development for the new GSI high-current injector
Bernardet et al. A highly reliable trigger for vacuum ARC plasma source
Bernardet et al. Investigation of firing properties of a vacuum arcs triggered by plasma injection