A 3-D chip is a three dimensional integrated circuit. In this chip the devices used are connected internally and performs analog, digital, neural network functions and image processing either individually or in combination.
3-D chip technology helps the chip manufacturers for reducing the processor size and increasing the performance. As these chips are becoming more powerful and smaller in size, the wires that are connected with the transistors are becoming necessarily closer and thinner. This will result in increase resistance and overheating. These will cause for the signal delay by limiting the clock speed of the central processing unit. With the support of Defense Advance Research Project Agency, IBM and Rensselear polytechnic Institute developed a new version of this 3-D chip in April 2007. IBM Company has made this 3-D chip by using a base layer of silicon with the active wafers layering on the top. This technique helps the engineers to place the processor at the stack and the memory layer at the top of the chip. This process helps in making the thousands of folds in to a connector length. In the two dimensional layouts the chips are no longer connected with the wires that are connected with the transistors, the processing of the chip will be faster. Similarly as the hundred folds increases in the connector density, the size of the chip reduces. IBM engineers used a new method called as “through silicon vias” which will allow the multiple components to be stacked upon another vertically, creating smaller, faster and low powered CPUs. This method also allows more efficient dissipation for the cooling system through the stack of the chip. According to IBM, improving the power efficiency in the silicon germanium based products up to 40% will reduce the battery life.
When IBM starts to producing these 3-D chips, initially BIG BLU applied this technology in to mobiles and wireless communication devices. In 2009 memory on processor technology is used in servers and supercomputers. In February 2007, Intel used a similar chip in its processor having capacity of a trillion calculations per second.