Multi-Gbit/s module for memory and processor products and method for improving the data transfer rate
Original Publication Date: 2001-Oct-01
Included in the Prior Art Database: 2003-Jul-23
The speed of electronic device is one of the con- cerned issues in microelectronic. Research and de- velopment are directed toward down scale of MOS transistor. Sub-micron technology has offered high- speed transistor. A 1GHz silicon chip is being manu- factured, but module of many silicon chips and dis- crete components is still operate at lower frequency than the silicon chip itself. This is mainly due to metal traces that are not able to hold an electronic high-speed signal. The bottleneck that the actual module is facing is how a signal of 1GHz that is de- livered by the silicon chip can be maintained on the bus of the module. In contrast to that and in other areas, it was demonstrated that laser light has solved some major problems that the pure electronic module is facing. The mixture of laser optic and electronic devices is widely used in Ethernet and has proved its capability in high-speed data transfer. A challenge of many Gb/s transfer rate is commercially available in telecommunication. In memory and processor pro- duction, the introduction of laser light for data trans- fer can make possible the development of a complete optoelectronic module with a speed above 1GHz. The solution detailed in this description is the way that the module should be made to respond to the equipment.
Multi-Gbit/s module for memoryand processor products and me-thod for improving the data trans-fer rate
Information / Kommunikation
Idee: Dr. Kamel Ayadi, München
The speed of electronic device is one of the con-cerned issues in microelectronic. Research and de-velopment are directed toward down scale of MOStransistor. Sub-micron technology has offered high-speed transistor. A 1GHz silicon chip is being manu-factured, but module of many silicon chips and dis-crete components is still operate at lower frequencythan the silicon chip itself. This is mainly due tometal traces that are not able to hold an electronichigh-speed signal. The bottleneck that the actualmodule is facing is how a signal of 1GHz that is de-livered by the silicon chip can be maintained on thebus of the module. In contrast to that and in otherareas, it was demonstrated that laser light has solvedsome major problems that the pure electronic moduleis facing. The mixture of laser optic and electronicdevices is widely used in Ethernet and has proved itscapability in high-speed data transfer. A challenge ofmany Gb/s transfer rate is commercially available intelecommunication. In memory and processor pro-duction, the introduction of laser light for data trans-fer can make possible the development of a completeoptoelectronic module with a speed above 1GHz. Thesolution detailed in this description is the way that themodule should be made to respond to the equipment.
Low cost and reliable package are the most con-cerned issues in optoelectronic module. Moduleequipped with waveguides and laser sources has acapability to easily transfer data at the speed of lasersource. Laser source made in other material thansilicon is general one to 10 orders of magnitudehigher in speed than that of silicon. 1GHz photore-ceiver in standard CMOS technology is possible toconvert light pulses to electronic pulses, it was re-cently demonstrated in [Woodwards99]. Waveguidecan be built in different materials such as plastic,polymer and glass. The real cost in packaging is thegeometric way that light should be guided.
Up to now the module was not changed in principle.The quality of the dielectric that is built between thelayers of the module was ameliorated so that couplingcapacitance is minimized. Also, the bus wires of themodule are terminated to a reference voltage, so thatthe swing voltage of the signal is kept low and theoperating frequency is therefore increased. In addi-tion to that, the electronic data is travelling at bothedges of the clock. A challenge of 800MHz datatransfer rate is being designed in the module, but itseems to be closed to the upper frequency limit.
Laser source con provide pulses at 10 to 100GHz,which means optical data of 10 to 100Gbit/s is possi-ble. Electronic data coming from the silicon chip (e.g.DRAM, processor) to the module bus at the speed ofe.g. 1GHz can be converted to light and delivered tothe silico...