Opinion ID: 671946
Heading Depth: 1
Heading Rank: 1

Heading: facts

Text: 2 The microelectronics industry constantly seeks more advanced technology to place more circuits on a semiconductor chip. Within this semiconductor chip technology, the claimed invention addresses the problem of combining circuits that have different thicknesses. The invention describes circuits which incorporate relatively thick light-emitting diodes (LEDs) into the same gallium arsenide (GaAs) substrate as the substantially thinner field-effect transistors (FETs). These FETs control the LEDs. Claim 1 states: 1. An integrated device comprising: 3 --a semi-insulating GaAs substrate layer, 4 --at least one channel etched into said substrate layer, 5 --a contact layer of a first conductivity type grown in and restricted to said channel(s), 6 --double heterostructure light-emitting diodes (LED) comprising a first layer of a ternary compound Alx Ga1-x As of a first conductivity type, a second light-emitting GaAs layer or a doped Aly Ga1-y As layer of said first conductivity type, a third layer of a ternary compound Alx Ga1-x As of a second conductivity type and a fourth doped GaAs layer of said second conductivity type grown on said third LED layer forming ohmic contact, each of said Leds being restricted to a channel and the individual LEDs being mutually insulated, 7 --a GaAs layer in which mutually insulated active FET area are formed, 8 --insulation means mutually insulating LEDs and FETs, 9 --a LED short circuit preventing layer at the edge of said channel(s), 10 --n-type and p-type metal depositions forming ohmic FET-source and FET-drain contacts, LED-electrodes and LED and FET interconnections, 11 --Schottky-type metal FET-gate electrodes, 12 --a LED and FET series resistance reducing metallization layer, 13 --LED windows etched in said fourth n-type GaAs LED layer[s]. 14 Claims 1 through 13 define the integrated circuit device. Claim 14 describes a recording head incorporating that device. The examiner rejected claims 1 through 13 under 35 U.S.C. Secs. 102(e) and 103 as being anticipated by, or obvious over, Wada et al., U.S. Patent No. 4,719,498 (Wada). The examiner rejected claim 14 as obvious over Wada in view of Iwata et al., Japanese Kokai No. 61-199681 (Iwata). 15 Wada teaches an integrated circuit device. Wada differs from the claimed invention in four areas: (1) the use of a laser diode (LD) 1 instead of an LED, (2) the use of only one light emitting element, (3) the lack of resistance-reducing metallization layer, and (4) the lack of a window etched into the LED. 16 According to undisputed facts on this record, one of ordinary skill in the semiconductor chip art would know that, under low current densities, an LD operates as an LED. Therefore, the examiner determined that the knowledge of a skilled artisan would eliminate the first difference between Wada and the claimed invention. Additionally, one of skill in the art would fabricate more than one light emitting element at a time. Thus, the examiner determined that the second difference between Wada and the claimed invention was inherently eliminated during high volume production. The examiner did not address the third and fourth differences. 17 The Board reversed the examiner. The Board detected no record evidence that an artisan of ordinary skill would normally operate the Wada invention at the lower current densities necessary to make the diode function as an LED. The Board also rejected the examiner's inherency argument for the second difference. The Board reasoned that, after production, multiple light emitting elements would ordinarily be separated for use. 18 The Board, however, rejected the claims on other grounds. The Board rejected the first 13 claims as obvious in view of Wada in conjunction with Pankove, 2 Itoh, 3 Sze, 4 and Levine. 5 The fourteenth claim fell when the Board added Iwata to this same combination.