Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
  • G01R23/02—Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
  • C23C14/54—Controlling or regulating the coating process
  • C23C14/542—Controlling the film thickness or evaporation rate
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
  • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
  • C23C16/52—Controlling or regulating the coating process

Definitions

• the present invention relates to a method of an apparatus for determining frequency of an unknown signal and operates at much higher speed than previous systems available at the price range proposed.
• the invention operates on the principle of determining the frequency of an unknown signal by counting a first frequency reference signal for a duration of time controlled by the unknown and counting a second higher frequency reference signal for the periods for which the reference overlaps or is otherwise out of phase with the first lower frequency reference signal. More specifically, apparatus is disclosed which generates a first 10 MHz reference signal and a second 100 MHz reference signal.
• the unknown signal whose frequency is to be determined triggers the 100 MHz reference signal on a falling edge of the unknown signal.
• the count of the 100 MHZ signal continues the duration of the 10 MHz reference signal from the aforementioned falling edge to the next rising edge of the unknown frequency.
• the process is then repeated triggering on the leading edge of the unknown signal which enables the 100 MHz high frequency clock for the duration of the 10 MHz reference signal until the occurrence of the falling edge of the unknown signal.
• the system could trigger in a reverse fashion: i.e. first on the leading edge, then on the trailing edge.
• the counts of 10 MHz reference signal and 100 MHz reference signal thus generated are analyzed by a computer program which operates in accordance with an algorithm to generate and display the frequency of the unknown signal.
• Additional capabilities are provided to enable the system to detect and track whether the unknown signal is at a preset given frequency.
• the circuit and program are used to control a physical system to drive it to a desired degree of accuracy.
• the invention can be used to control the frequency and duration of plating rate to achieve a very high resolution of 1 ppm by controlling the plating speed at a higher rate when the count is approaching the desired target frequency and at a slower, decreasing rates when the count is near and approaching the target frequency.
• Prior art frequency measurement techniques are available such as the universal freqency counter technique or the multiplication of frequency technique both of which achieve improved resolution at faster counter rates.
• the disadvantages of these prior art techniques is that the universal freqency counter method is limited to a maximum speed of 150 counts per second and is costly. In addition, the resolution of the measurement by this method is inaccurate.
• the multiplication method provides high resolution; however, errors in the detection are multiplied along with the desired signal so that resolution here is not satisfactory for the highest resolution applications.
• Applicant believes that the combination of a low cost personal computer programmed in accordance with the program described herein and the high speed frequency calculation circuit is an improved low cost frequency determination scheme.
• the computer reads the frequency analysis data rapidly at time intervals then resets the frequency analysis circuitry so as to free it to continue to accurately analyze the unknown signal in accordance with the method described herein.
• This parallel processing of frequency data enables the computer to analyze and determine the unknown frequency at very high speed.
• An object of the present invention is the provision of a high speed frequency analysis method and apparatus. Another object of the present invention to utilize a personal computer programmed to determine the frequency of an unknown signal which when coupled to unique circuitry, provides frequency analysis data to the computer in a parallel rather than a serial fashion.
• Another object of the present invention is the provision of a control system for high resolution applications which varies the speed of the controlled system starting at a high speed and slowing, as the desired resolution is achieved.
• Fig. 1 is a block diagram of the system in accordance with the invention.
• Fig. 2 is a wave form diagram of the various signals for timing and counting the unknown frequency
• Fig. 3 is a schematic diagram of the edge detection and control circuitry which detects the leading and trailing edges respectively of the various pulses of the unknown frequency and controls the high and low frequency reference counters;
• Fig. 4 is a block diagram of the frequency control system of Fig. 1 applied to final calibration of quartz crystals. Brief Description of the Drawing
• Fig. 1 is a block diagram of the computer hardware and digital circuitry employed in the invention. More particularly, numeral 2 denotes a digital computer of the popular PC type such as the APPLE IIE. Coupling the computer to the other circuitry is an interface unit 4 which will be described in connection with Fig. 3 below. Suffice it to say, however, that interface 4 uses ICs 74LS244, 74LS273, 74LS245 and 74LS151 which are well known ICs for interface applications connected in accordance with the directions contained in integrated circuit handbooks such as the Data Interface Handbook.
• ICs 74LS244, 74LS273, 74LS245 and 74LS151 which are well known ICs for interface applications connected in accordance with the directions contained in integrated circuit handbooks such as the Data Interface Handbook.
• Numeral 30 denotes the unknown signal whose frequency is to be measured.
• the invention employs two oscillators; a 10 MHz low frequency oscillator shown at numeral 20 which in practice is manufactured by CTS, Knight Corporation or Motorola and is known as a 10 MHz TCXO oscillator (temperature compensated crystal oscillator), and a high frequency 100 MHz oscillator shown in numeral 28 which, in practice, is also manufactured by CTS, Knight Corporation and is a standard commercial product.
• Buffers 6, 8, 10 and 12 respectively are provided to control signal transfer and loading as is standard practice. These buffers are integrated circuits 74LS244 manufactured by a wide variety of electronics concerns. Latches 14 are provided to connect the interface unit to test frequency counters which will be described later. These latches are again standard to provide signal conditioning and transfer. In practice latches 14 are an integrated circuit 74LS273 widely available commercially. The source of unknown frequency signal 30 is connected to test frequency counters 16. These counters are integrated circuits known as 74LF191 commercially available. In practice, 8 of these integrated circuits are connected together and are controlled by the computer via latch 14 to reset all the counters to zero so that the counters will zero and transfer data in parallel to enable the high speed data transfer of the present invention. The configuration of 74LF191 as a counter is well known in the integrated circuit handbooks.
• test frequency counter 16 is the same configuration as that employed in counters 18. Counter 16 counts the low frequency 10 MHz reference signal from oscillator 20.
• high frequency oscillator 28 has its output connected to a counter 26, which starts and stops under control of the edge detection control circuitry 22 which will be described in detail below.
• the output from the 100 MHz oscillator is connected to the computer via buffers 10, previously described.
• Latches 14 control the measurement speed by presetting the expected 10 MHz and 100 MHz counts in that preset period of time.
• Fig. 3 shows the edge detection and control circuit of the present invention
• the circuit consists of four line driver integrated circuits 32, 34, 36 and 38. These circuits are commercially available integrated circuits 74LS76.
• the inputs to line driver 32 are control signals from the computers' memory 50 and 52. These control signals enable and disable the edge detection and counter control circuitry in a manner which will be described further.
• numeral 30 is the source of unknown frequency. This unknown frequency is connected to line driver 34 via lines 24.
• the low frequency 10 MHz oscillator 20 is connected to line driver 36 and to line driver 38.
• Suitable gates for control which will be described below are shown at numerals 54, 56, 58, 60, 62, 64, 66, 68 and 70.
• letters corresponding to the electrical signals shown on Fig. 2 appear.
• the letter X appearing at line 24 at Fig. 3 is wave form X in Fig. 2.
• wave form Y in Fig. 2 appears at the output of line driver 32 in Fig. 3.
• the wave forms of Fig. 2 find correspondence at various points in Fig. 2 as will be discussed below.
• the control outputs of Fig. 3 at points 42, 44, 46 and 48 are connected as follows: control output 42 starts the 100 MHz counter which is shown in Fig. 1 as 26; control output 44 disables the test frequency counters 16 in the block diagram of Fig. 1; control output 46 stops the high frequency counter 26 in the block diagram and, lastly, control output 48 disables counter 18 in Fig. 1.
• the enable signal Y appears at the output of line driver 32 on command from the computer.
• wave form X is the unknown frequency which is inputted to line driver 34 via line 24.
• the clear wave form signal on the third line of Fig. 2 is generated by the other output of line driver 32 and clears all counters.
• the 10 MHz reference signal shown in Fig. 2 as the fourth wave form therein. Points Z, D, and a are shown on this wave form which will appear at corresponding points in the schematic of Fig. 3.
• the 100 MHz reference signal is shown counting the trailing edge of the unknown signal and subsequently the leading edge of the unknown signal all as will be described later.
• the trailing edge of the unknown frequency X triggers the start of the 100 MHz enable signal at wave form F point 42.
• This 100 MHz enable is triggered by the output of line driver 34 via gates 56 and 58.
• the duration of the 100 MHz enable signal is from point F to point Z, point Z being the occurrence of the trailing edge of the 10 MHz reference signal generated by oscillator 20 and fed to the input of line driver 36.
• a count is developed which considers the duration of the test frequency signal from the trailing edge to the leading edge thereof in terms of 100 MHz reference signals for the duration of the 10 MHz reference signal.
• the leading edge of the test frequency signal or unknown frequency signal at wave form C is developed. More particularly, points Z and a of the 10 MHz reference signal appear at the input to line driver 36 and 38 respectively. This, in turn, triggers wave form point E at output 46 of gate 66 which disables the 100 MHz counter 26 in Fig. 1.
• the 100 MHz count thus generated considers the interval of 100 MHz counts at the leading edge of the unknown signal.
• the equation for determining the frequency in the computer program is:
• Counter 72 in Fig. 3 counts the test frequency to zero and consists of integrated circuits 74F191 commercially available configured in a up/down counter configuration as is well known. This counter triggers on point D of the 10 MHz reference signal via line driver 38 and gate 64.
• Fig. 4 shows the application of the frequency counter apparatus and computer program described below to a vacuum deposition process.
• vacuum deposition of, for example, quartz crystals utilize a vacuum chamber 1 which operates under control of known control circuits 3 and which contains an oscillator driving crystal 5 to control the frequency of the deposition process.
• the apparatus and computer of the present invention are shown at 7 and 9 where the frequency counter 7 includes the circuitry previously discussed and computer 9 is the digital computer 2 incorporating the program described herein.
• the frequency counter 7 thus detects the frequency of deposition from the oscillator driving crystal 5 in the vacuum deposition chamber.
• the computer directly controls the deposition rate via control circuits 13 and volume, via shutter control in the chamber 1.
• lines 250-850 perform the initialization of the system variables; lines 865-1105 implement the system self test; lines 1120-1330 and 1345-1810 offer the operator's initialization run and the operator's set-up functions, if necessary.
• Lines 3610-8115 constitute the vaporization control function described above.
• the predicted values of plotting speed are loaded into the computer at line 8200.
• the remainder of the program through line 53000 also control the vacuum deposition operation.
• JLIST 1 ONERR GOTO 50000 10 REM CRYSTAL TUNING PROGRAM REV 1 25 REM COPYRIGHT 1985 40 REM ANY UNAUTHORIZED DUPLICATION OF THIS PROGRAM IS FORBIDDEN BY LAW 55 REM 70 REM START OF PROGRAM 85
• GOSUB 1120 REM OPERATOR INITIALIZATION 130
• GOSUB 1345 REM ENGINEERING DISPLAY 145
• GOSUB 1825 REM MAIN MENU
• GOSUB 865 GOTO 145: REM RUN SELFTEST
• GOSUB 1120 GOTO 145: REM NEW OPERATOR 205
• GOSUB 1345 GOTO 145: REM NEW ENGINEERING DATA
• GOSUB 2080 GOTO 145: REM WRITE REPORT
• GOSUB 2035 GOTO 145: REM SAVE FINAL DATA, WRITE REPORT AND POWER DOWN
• VTAB (4) HTAB (15) : INPUT NA$: VTAB (4) : HTAB (40) : PRINT ":";
• VTAB (8) HTAB (15) : INPUT SA$: VTAB (8) : HTAB (40) : PRINT ":";
• INPUT C1 INPUT C2: INPUT DI$: INPUT CH$: INPUT C$: INPUT P$: INPUT CU$
• VTAB 1560 VTAB (15) : HTAB (25) : FLASH : PRINT DI$: NORMAL
• VTAB (16) HTAB (25): FLASH : PRINT CU$: NORMAL
• VTAB (17) HTAB (25): FLASH : PRINT CH$: NORMAL
• VTAB 1705 VTAB (21) : HTAB (1) : PRINT HTAB (40) : PRINT ":";
• VTAB 1780 VTAB (23): HTAB (10) : INPUT "ENTER ⁇ CR> TO CONTINUE” ;K$
• VTAB (I): HTAB (1): PRINT ": :”; : NEX
• VTAB (1) HTAB (2): PRINT " ⁇ >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>”;
• VTAB HTAB (HE): PRINT HE$;
• VTAB 2935 VTAB (24): HTAB (2): PRINT " ⁇ >>>>>>>>>>>>>>>>>>>>>>>>>”;
• VTAB (24): HTAB (HE): PRINT HE$;
• VTAB (1) HTAB (2): PRINT " ⁇ >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>”;
• VTAB 3025 VTAB (1) HTAB (HE) : PRINT HE$;
• VTAB 3060 VTAB (24): HTAB (2): PRINT " ⁇ >>>>>>>>>>>>>>>>>>>>>>>>>”;
• VTAB 3100 VTAB (24): HTAB (HE): PRINT HE$;
• VTAB ((33)): HTAB (3): PRINT "1. 10MHZ XTAL CAL"
• VTAB 3370 VTAB (15): HTAB (2): PRINT D$;"OPEN ENGRDATA,S6,D1"
• PRINT C1 PRINT C2: PRINT DI$: PRINT CH$ : PRINT C$: PRINT P$: PRINT CU$
• VTAB (13): HTAB (8): PRINT "READ THE 10 MHZ VALUE"
• VTAB HTAB (3): PRINT "CHANGE CALIBRATION (Y OR N) " ; : GET K$
• GOSUB 3460 VTAB (12): HTAB (3): INPUT "ENTER NEW 10MHZ CAL VALUE: ";C2
• VTAB 3565 VTAB (14): HTAB (3): PRINT "VALUE CORRECT (Y OR N) ";: GET K$
• GOSUB 3460 VTAB (3): HTAB (22): PRINT SPC( 18);":": GOTO 3265
• VTAB (11) HTAB (3): PRINT "PLATING RATE MEAS.TIME CUTOFF"
• VTAB (12): HTAB (3) : PRINT " PPM/SEC SECONDS +PPM"
• VTAB (17) HTAB (3): INPUT "ENTER MEASUREMENT RATE:”;T(2): HTAB (40): PRIN
• GOSUB 3460 VTAB (12): HTAB (3): PRINT "CHAMBER OPERATION MODE SELECTION"
• GOSUB 3460 VTAB (12): HTAB (3): INPUT "ENTER NEW PASSWORD " ;K$
• VTAB (14): HTAB (3): PRINT "CORRECT (Y OR N) ";: GET L$
• GOSUB 3460 VTAB (12): HTAB (3): PRINT C$
• VTAB (14): HTAB (4): PRINT "CHANGE COMMENTS (Y OR N>? " ; : GET K$
• VTAB HTAB (2): PRINT SPC( 38): VTAB (18): HTAB (40): PRINT ":” 5100)VTABINT9 : "HTAB (2) : PRINT SPC( 38): VTAB (19): HTAB (1) : PRINT ":”;: HTA
• VTAB HTAB (3): PRINT "ENTER NEW COMMENTS. (36 CHARS MAX)"
• ARBA I 12 TO 19: VTAB (I): HTAB (30): PRINT SPC( 10) : NEXT : REM ERASE
• GOSUB 10100 REM SAVE DATA BUT KEEP XTAL POINTER IF LESS THAN 50
• V5 PR(RA,1) + (PR(RA,2) * 256) + (PR(RA,3) 65536) + (PR(RA,4) * 1677721
• V5 V5 / DT
• V5 V5 / 1E6: REM SET UNITS TO MHZ
• REM PM PARTS PER MILLION DELTA FROM TARGET 8551
• REM V5 ACTUAL FREQUENCY IN MHZ 8599
• GOSUB 8500 REM GET FREQUENCY AND PPM
• VTAB 9550 VTAB (12): HTAB (30): PRINT LEFT$ (K$ + " ",10)
• VTAB (18) HTAB (20) : PRINT SPC( 18);: HTAB (20): PRINT V5 24085 VTAB (19): HTAB (20): PRINT SPC( 18);: HTAB (20): PRINT PM 24090 GOTO 24040
• VTAB (14): HTAB (4): PRINT "ENTER FREQUENCY IN MHZ:
• V5 PR(RA,1) + (PR(RA,2) *
• V5 V5 / DT
• PR(RA, 1) POKE 4 9313,PR(RA,2) : POKE 49314, PR (RA,3) : POKE 49315, PR (RA, 4)
• VTAB HTAB (3): PRINT "ENTER NEW COMMENTS. (36 CHA RS MAX)"
• VTAB (3) HTAB (20) : PRINT SPC( 15) : GOTO 5200
• HE$ NEXT : NORMAL 2070 VTAB (15): HTAB (4): PRINT
• ATA SETUP ROUTINE 3460 FOR I 11 TO 22 : VTAB ( I ) : HTAB (1): PRINT “ : " ; SPC( 3
• VTAB 1735 VTAB (I + 7): HTAB (7): PRINT P(I);: HTAB (20): PRINT M(I) ;: HTAB (31) : PRINT C(I)

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• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• General Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Television Signal Processing For Recording (AREA)
• Chemically Coating (AREA)
• Feedback Control In General (AREA)
• Other Investigation Or Analysis Of Materials By Electrical Means (AREA)

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• 1986
  • 1986-05-23 AU AU59521/86A patent/AU5952186A/en not_active Abandoned
  • 1986-05-23 JP JP61503056A patent/JPS62503056A/ja active Pending
  • 1986-05-23 EP EP19860903860 patent/EP0224563A4/en not_active Withdrawn
  • 1986-05-23 WO PCT/US1986/001098 patent/WO1986007156A1/en not_active Application Discontinuation
  • 1986-05-28 ES ES555416A patent/ES8801866A1/es not_active Expired
• 1987
  • 1987-01-27 KR KR870700066A patent/KR880700272A/ko not_active Application Discontinuation

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