Microelectronics

A mainframe (in the test phase | during (a test run | testing | trial)): (Mastering | Managing) [of] the complexity - from the beginning of the (draft | initial design) to (acceptance | commissioning) by the quality assurance is a (decisive | crucial | essential) (prerequisite | qualification | precondition) for function[ing] and quality of electronics systems.

(Still | Even) smaller dimensions and (ever | always) (faster | higher) speeds (identify | characterize | define | label | mark | outline | are the keynotes of) the development-(tendencies | trends) in microelectronics [industry].

In [tele]communications- and data systems technology, in the process- and control engineering and even in consumer electronics circuits are (required | needed | called for) with typical "gate switching times" of less than 100 picoseconds - (during this | in (that | this) time) the light (covers | travels) (just about | a mere) 3 centimetres.

The 64-kilobit-memory has developed in less than 10 years into the 4-megabit (memory | store). The text of 250 typewriter pages can be (accommodated | stored | saved) in one such chip on an area less than one square centimetre. (All over the world | World-wide | Globally) the developers are (currently | in the meantime) (busily | intensively) working on the 16-megabit-memory.

Along with rising integration density more and more functions can be (concentrated on | accommodated on | implemented with) (a single | only one) chip (... | Given the increasing scale of integration ...). The complexity of circuits leads to (increasing | growing) problems in design, fabrication and (testing | inspection | check).

Technologies for (fast circuitry | high-speed (circuits | switching))

Bipolar technology

The (classical | conventional) bipolar-technology (harnesses | utilizes | exploits | makes use of) the physical effects on the (border | boundary) surfaces of p- and n-conducting silicon. (Minute | Small | Minor) (alterations | variations | changes) of a low (control | gate) current (result in | lead to) (significant | large | major) changes of the collector current: The transistor can (operate | function | work | act) as an amplifier or as a switch.

In order to (obtain | attain | gain | yield | achieve) high switching speeds, the parasitics on a chip (bulk resistances and capacitances) and the dimensions of the transistors (emitter penetration depth and base width) have to be (reduced | decreased). We have developed a new oxide-isolation (along | together) with a self-adjusting nitride-sidewall-masking, (that makes possible both | enables in addition to) a nearly ideally planar surface (and | also) a (significant | distinct | clear) reduction in horizontal dimensions.

The critical vertical dimensions can be reduced by means of (rapid | short-time) annealing with an optical energy source (Rapid Optical Annealing) instead of a conventional furnace annealing. (Thus | By those means) we have obtained emitter depths of less than 50 nanometers and basis widths below 120 nanometers at (significantly | considerably) higher electrical activation rates.

Gate switching times of 40 picoseconds (is what we have achieved so far with | are the (current | present) result of) such measures. By means of a static 16:1-frequency divider as test circuit we have (attained | achieved) (operating | working) frequencies of 15 GHz. A word generator (out of | from) D-flip flops, multiplexers and frequency dividers works with a data transfer rate of 5 gigabit/s; by means of a downstream 2:1 -(mux | multiplexer) we have doubled the data transfer rate to 10 gigabit/s.

15-GHz-frequency divider

Input signal (at the top): 15 GHz

Output signal (at the bottom): 938 MHz.