摘要:
A Schottky diode is fabricated according to the following steps: forming a layer of metal-silicide on an underlying dielectric layer, forming a polysilicon layer on the upper surface of the metal-silicide layer, forming a second dielectric layer on the upper surface of the polysilicon layer and patterning the second dielectric layer to create a contact window through the second dielectric layer to an exposed surface region of the polysilicon layer, and forming a metal contact to the exposed surface region.
摘要:
An electrically erasable programmable read-only memory (E 2 PROM) is provided which utilizes an inhibit voltage applied to unselected word lines during writing to prevent writing in unselected rows. In the preferred embodiment, each memory cell of the E 2 PROM array consists of a single floating gate field effect transistor. The E 2 PROM of the present invention provides for row erasure and single bit writing.
摘要:
A method and apparatus is described for dynamically testing the overall performance characteristics of digital-to-analog converts and analog-todigital converters which involve excitation of the converters by an orthogonal function signal. Specifically the method comprises dynamically exercising a converter with an analog or digital signal pattern characterized by the sum of a set of mutually orthogonal functions, the sum having substantially uniform amplitude distribution among allowable states (maximum entropy), and simultaneously examining the output response of the converter for a plurality of basic performance parameters. The basic performance parameters typically include distortion, linearity and optimum gain. The simultaneous examination involves sorting out expected responses to simultaneously applied orthogonal signals. The method yields a relatively complete statistical description of the performance characteristics. The preferred excitation is based on the Walsh functions. The output response is readily analyzed by Fast Walsh Transform processors.
摘要:
A timing subsystem 10 including several test period generators for supplying a variety of timing signals to a device under test. Major, minor, and free-run period generators each supply various timing signals to a multiplexer 18, which selectively connects the timing signals to timing generators 20. A central processing unit 28 supplies data to the period generators and timing generators to define their respective timing signals. Timing signals generated by the major period generator 12 define the overall testing rate. The minor period generator 14 generates multiple timing signals within the periods of the major clock signals to permit higher clock rates. Timing signals that are independent of the major clock periods are generated by the free-run period generator 16. An external synchronizer circuit 26 provides a feedback loop from the device under test 22 to the major period generator. A reference driver trigger delay circuit 27 provides means for calibrating the timing generators. Each of the three period generators includes two interconnected timing interval generators 30 and 40 that alternately generate overlapping timing signals. Each timing interval generator includes a stop-restart oscillator 32, a counter 34, and a delay-line vernier 36. Upon the receipt of a start signal, the oscillator stops and restarts to align its clock pulses to the start signal. The oscillator output clocks the counter, which supplies a signal to the vernier when a preselected number is reached. The vernier delays the counter signal by a preselected delay and issus a signal that designates the end of the period.
摘要:
A process for improving the quality of an oxide thermally grown or doped polysilicon by doping the polysilicon so that the V I resistance of the polysilicon is less than approximately 3 ohms as measured by a companion single crystal test wafer The process applied to an EPROM device eliminates deprogramming defects in the device.
摘要:
A timing subsystem 10 including several test period generators for supplying a variety of timing signals to a device under test. Major, minor, and free-run period generators each supply various timing signals to a multiplexer 18, which selectively connects the timing signals to timing generators 20. A central processing unit 28 supplies data to the period generators and timing generators to define their respective timing signals. Timing signals generated by the major period generator 12 define the overall testing rate. The minor period generator 14 generates multiple timing signals within the periods of the major clock signals to permit higher clock rates. Timing signals that are independent of the major clock periods are generated by the free-run period generator 16. An external synchronizer circuit 26 provides a feedback loop from the device under test 22 to the major period generator. A reference driver trigger delay circuit 27 provides means for calibrating the timing generators. Each of the three period generators includes two interconnected timing interval generators 30 and 40 that alternately generate overlapping timing signals. Each timing interval generator includes a stop-restart oscillator 32, a counter 34, and a delay-line vernier 36. Upon the receipt of a start signal, the oscillator stops and restarts to align its clock pulses to the start signal. The oscillator output clocks the counter, which supplies a signal to the vernier when a preselected number is reached. The vernier delays the counter signal by a preselected delay and issus a signal that designates the end of the period.
摘要:
A data processing system (20) incorporates host processors (22 and 24) connected by network interface units (28 and 34) to a coaxial cable (26). The network interface units (28 and 34), cable (26), and network interface units (40-56) form a local area network capable of carrying out processing operations on information independent of the host processors (22 and 24). As a result, interrupts of the host processors (22 and 24) for data transfer operations are significantly reduced, allow- , ing the system (20) to support a much larger number of user terminals and other peripherals.
摘要:
A method, timing control circuit, and power supply are described for initiating arc discharge between the cover gas delivery shroud and lead wire held in the bonding tool of a lead wire bonding machine for melting and forming a ball at the end of the lead wire. An arc discharge timing control pulse controls duration of the arc discharge within an empirically determined time window between the shortest and longest durations of arc discharge which result in optimal ball formation of a substantially spherical ball at the end of the lead wire without necking of the lead wire above the formed ball. The timing control circuit also provides an initial cover gas movement delay before ball formation for displacing oxygen from the shield and the end of the lead wire, and a subsequent cooling delay for solidifying and cooling the formed ball in the cover gas stream prior to ball bonding. Initially, the lead wire tail length extending below the bonding tool is selected to provide a ball of specified size; the voltage is selected according to tail length to form the mass of tail length metal into a substantially spherical ball; and a neck of desired thickness is selected by adjusting the duration of the arc discharge timing control pulse within the time window.
摘要:
An improved lift-off process for forming metallized interconnections between various regions on a semiconductor device relies on the use of a particular polyimide in forming a protective mask over the device. The polyimide is a copolymer of an aromatic cycloaliphatic. diamine and a dianhydride which allows the resulting structure to withstand particularly high temperatures in the fabrication process. In particular, the polyimide when subjected to high temperature metallization under vacuum remains sufficiently soluble to be substantially completely removed from the device by immersion in common organic solvents. This allows high temperature metallization as interconnects for integrated circuits.