公开(公告)号：DE1261164B

公开(公告)日：1968-02-15

申请号：DEJ0028450

申请日：1965-06-26

Applicant: IBM

Inventor： FLEISHER HAROLD ,  KOSANKE KURT MAX

IPC: G02F3/00 ,  H01L27/00 ,  H01L27/144 ,  H01L31/00 ,  H01L31/12 ,  H03F3/08 ,  H03H11/02 ,  H03K17/795 ,  H03K19/14

公开(公告)号：DE1259380B

公开(公告)日：1968-01-25

申请号：DEJ0029483

申请日：1965-11-19

Applicant: IBM

Inventor： KOSANKE KURT MAX ,  KULCKE DR WERNER WOLFGANG ,  MAX DR ERHARD

IPC: G02F1/03 ,  G11C27/02 ,  H03K3/53 ,  H03K17/78

Abstract: 1,089,408. Modulating light; pulse circuits. INTERNATIONAL BUSINESS MACHINES CORPORATION. Oct. 14, 1965 [Feb. 24, 1965], No. 43567/65. Headings H3P and H4F A circuit for charging and discharging a capacitive load, e.g. an electro-optic crystal 8, comprises a tank capacitor 12 connected through an inductance 10 to the unearthed crystal plate 9 so as to form an oscillating circuit. Diodes D1 and D2 which block the flow of current towards the inductance but permit current to flow in the opposite direction are connected at the ends of the inductance and are by-passed by switches S1 and S2 which are closed intermittently by pulses derived from the data pulses, as shown, so as to transfer electrostatic energy from the tank capacitor to the crystal plate and then to return electrostatic energy from the crystal plate to the tank capacitor. After each return of energy to the tank capacitor i.e. after switch S2 is opened, a voltage pulse is applied to the tank capacitor through diode D4 to compensate for any losses, e.g. resistance losses, occurring during the operation of the circuit, and at the same time to ensure that the crystal is completely discharged the voltage on conductor 14, which is connected through diode D3 to the crystal plate and is normally subjected to a voltage equal to the initial voltage to which the tank capacitor is originally charged, is reduced to zero. The voltages on conductors 14 and 16 are derived from clock pulses which arc differentiated 20, delayed 22 and applied to a monostable circuit 24. In order that a half wave voltage may exist on the crystal by the discharging of the tank capacitor it is necessary that the initial voltage be greater than the half wave voltage by an amount equal to the voltage remaining on the tank capacitor after discharging. When the half wave voltage is applied across crystal 8 the plane of polarization of the plane polarized light from source 4 is changed by 90 degrees and thus the light is deflected in birefringent element 6.

公开(公告)号：GB1134373A

公开(公告)日：1968-11-20

申请号：GB3329967

申请日：1967-07-20

Applicant: IBM

Inventor： KOSANKE KURT MAX ,  KULCKE WERNER WOLFGANG ,  MAX ERHARD

IPC: G02F1/31 ,  G03B15/00 ,  G03F9/00 ,  H01L21/00 ,  H01L21/68 ,  H03K17/78

Abstract: 1,134,373. Optical alignment apparatus. INTERNATIONAL BUSINESS MACHINES CORP. July 20, 1967 [July 21, 1966], No.33299/67. Heading G2J. Apparatus for optically aligning an object such as a semi-conductor wafer 1 with a reference mark 6 comprises an optical deflecting system 15, 16 which transmits a beam of radiation from a reflecting reference mark 5 on wafer 1 towards mark 6, control devices 18, 19 causing deflecting systems 15, 16 to scan the beam over the plane 17 containing mark 6 in accordance with a predetermined raster, a photo-cell 20 interrupting the scanning operation when the beam is incident on mark 6. Printed circuit patterns 22 are to be projected successively on to the photo-sensitized surface of wafer 1, and the wafer is first roughly aligned with the projection axis by screws 3, 4. The optical axis is then finally adjusted relative to the wafer using a subsidiary monochromatic light source 8 to which the wafer surface is insensitive, and a light switch 7. Light polarized at 11 passes via beam-splitter 12, lenses 13, 4 and devices 7, 15, 16 on to the area containing mark 5 and is reflected back through the system on to reference mark plane 17. When alignment of the projection axis is achieved, radiation from source 8 is cut off by switch 7 and the wafer is exposed to the pattern 22 which may be in hologram form using polarizing laser 24. Light switch 7 comprises an electro-optical crystal (31), Fig. 2 (not shown), to which a voltage (V) may be applied whereby the plane of polarization of a monochromatic light beam is rotated through 90 degrees, a birefringent plate (32) and a reflecting plate (33). Polarizer (34) passes light polarised in direction (41) only which is that of light beam (40) from source 8. Beam (44) from the laser is polarized at 90 degrees to direction (41) and is therefore only passed when crystal (31) is energized. Beams (40), (44) correspond to the extraordinary and ordinary beams for plate (32). Deflection units 15, 16 operating in X and Y directions are similar to switch 7 and comprise five electro-optical elements each followed by a birefringent element through which light may pass, depending on the state of the electro-optical elements, either as an ordinary or a deflected extraordinary beam. Each birefringent element is twice the thickness of its preceding element. The scanning deflections of the beam are obtained by activating the electro-optical elements in succession through five inter-connected bi-stable devices each with a switching frequency half that of the preceding device. The outputs of these devices are fed to the electro-optical elements through a logic circuit whereby each may be activated without affecting its neighbours. Rotational adjustment of wafer 1 is possible by using a Piezo-electric torsional support whereby the wafer may be rotated until moirÚ patterns due to lines on the wafer and reference mark reach a standard setting as sensed by photo-cells.