Monday, June 07, 2010

US Patent 7727786 - Photonic DRAM with nanotube layer

DRAM is popular as the main memory in personal computers due to its simplicity and small size. However, the requirement for frequent memory refreshing makes DRAM highly inefficient. This patent from Micron teaches a photonic memory variation in which the bits are stored based on photons in a phosphorescent material and in which aligned nanotube arrays are used to reduce crosstalk between adjacent memory cells. Claim 1 reads:

1. A method of fabricating a memory die, comprising the steps of:

forming a semiconductor substrate supporting a memory cell array, the memory cell array formed by:

forming a plurality of pixels on the semiconductor substrate, each pixel capable of emitting and receiving light; and

forming a material over the plurality of pixels, the material having nanotubes formed therein, the nanotubes having phosphorescent material localized over each pixel, the phosphorescent material capable of receiving light from and emitting light to the pixel; and

electrically coupling the memory cell array to the semiconductor substrate.