公开(公告)号：US3599116A

公开(公告)日：1971-08-10

申请号：US3599116D

申请日：1968-07-05

Applicant: TEXAS INSTRUMENTS INC

Inventor： SPENCE HILTON W ,  BOHANNON RALPH O ,  JEFFREY EDWARD N

IPC: G01J1/42 ,  G01J1/44 ,  H01L21/00 ,  H01L27/144 ,  H01L31/10 ,  H01L31/12 ,  H03K3/282 ,  H03K7/06 ,  H03K7/08

CPC classification number: H03K3/2823 ,  G01J1/42 ,  G01J1/44 ,  H01L21/00 ,  H01L27/1443

Abstract: A circuit for producing an electrical signal proportional to light intensity having two amplifiers interconnected in a multivibrator configuration. The timing circuit of one amplifier is a standard RC circuit and in the second a photodiode. In one configuration, the amplifiers including associated transistors, resistors and capacitors along with a light sensitive diode are fabricated as an integrated circuit on a monolithic substrate. Because the device responds to light in the visible range which is absorbed close to the incident surface of silicon, the diffused diode must be as thin as possible to obtain the desired high light current. A process for fabricating the light sensitive diode and associated circuitry includes the step of a dilute deposition of phosphorous oxytrichloride for the transistor emitter. Special processing techniques are employed to minimize thermal shock and dislocations.