Search

We have fabricated 77 K deep-submicron MOSFETs on the basis of the temperature-dimension combination scaling theory (CST). The 77 K MOSFETs with 1-V supply voltage are designed from a 300 K MOSFET with 4-V supply voltage. The fabricated 77 K 0.18 /spl mu/m device has exhibited fully scaled characteristics. The subthreshold swing (S) and the threshold voltage (V/sub th/) of the 77 K device are found to be 1/4/spl ap/77 K/300 K of those of the 300 K device. Furthermore, S and V/sub th/ are achieved to be 27 mV/dec and 0.21 V without short-channel effect degradation. >

An asynchronous spread spectrum (SS) modem in the 2.45-GHz band has been implemented using an efficient ZnO-SiO/sub 2/-Si surface acoustic wave (SAW) convolver. The modem, which can operate under full duplex transmission is based on a direct-sequence/code-shift-keying (DS/CSK) method for the modulation. Pseudonoise (PN) codes are chosen from a preferred pair of m-sequences of period 127, and the code rate is 14 MHz. The demodulation is carried out asynchronously, utilizing the coherent correlation characteristics of the SAW convolver. The main interference caused by a transmitted signal in the modem itself is effectively reduced by an RF isolator and the SS process gain. Adequate self-jamming rejection capability has been confirmed; a bit error rate of 10/sup -6/ is observed at -78.3 dB of a desired-to-undesired-signal ratio using an artificial transmission line. >

Lowering both the threshold voltage (V th ) and subthreshold swing (S) at the same time is essentially required for 0.1 μm and below 0.1 μm MOSFETs with low supply voltage. In this paper, we discuss a temperature scaling concept of MOSFET and the device characteristics of the fabricated 77K MOSFETs. In the temperature scaling concept, the physical quantities relating to potential are scaled with operation temperature, while the dimensional quantities are constant. The distribution of mobile carrier concentration are kept constant. In order to design 0.1 μm MOSFET with low supply voltage, we proposed the temperature-dimension combination scaling theory (CST). The 77K MOSFET with supply voltage of 1-V has been designed from a 300K parent device on the basis of the combination scaling theory. The fabricated 77K-CST 0.18 μm MOSFET has exhibited fully scaled characteristics. The subthreshold swing (S) and the threshold voltage (V th ) of this device is achieved to be 27 mV/dec and 0.21 V without degradation of S and V th due to the short-channel-effects degradation

Experiments on a two‐dimensional acoustic distributed feedback (ADFB) laser are described. A set of distributed Bragg reflectors (DBR’s) were formed on a GaAs crystal which was optically pumped at liquid‐nitrogen temperature and an surface acoustic wave (SAW) at a frequency around 1.2 GHz was injected into the planar region between the DBR’s. We observed the oscillation of the two‐dimensional ADFB modes. The SAW power, needed for the onset of the oscillation of the modes, was about 5 mW under the present experimental condition. Some discussions on its applications are briefly described.