We combine a self-organizing diblock copolymer system with semiconductor processing to produce silicon capacitors with increased charge storage capacity over planar structures. Our process uses a diblock copolymer thin film as a mask for dry etching to roughen a silicon surface on a 30 nm length scale, which is well below photolithographic resolution limits. Electron microscopy correlates measured capacitance values with silicon etch depth, and the data agree well with a geometric estimate. This block copolymer nanotemplating process is compatible with standard semiconductor processing techniques and is scalable to large wafer dimensions.

Thin films of self-organizing diblock copolymers may be suitable for semiconductor applications since they enable patterning of ordered domains with dimensions below photolithographic resolution over wafer-scale areas. We investigate the process window for forming ordered arrays of nanoscale polymer domains in thin films across 8-in.-diam silicon wafers, including the effect of substrate material and surface treatment, annealing conditions, copolymer molecular weight, and film thickness. We also demonstrate pattern transfer of the nanoporous polymer template using both reactive ion etching and metal lift off.

A novel spectrometer is employed to study the spectrum of heavily doped quantum dots. A single-particle discrete spectrum is found to exist only in close vicinity to the Fermi energy. Levels further away are broadened beyond the average level spacing and merge to form a quasi-continuous spectrum. The broadening is traced to electron-electron interaction in the dot. For the discrete part of the spectrum, level statistics is studied as a function of magnetic field and found to agree remarkably well with recent calculations.

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Multi-quantum-wire strained lasers are reported in the Ga,-,In.tAs/Ga,-.,Al,As semiconductor material system with a minimum threshold current of IX8 ,xA and maximum powers of =50 PW in continuous multimode operation at wavelengths of-=4RO nm and differential output of =0.5 ,LLW/ ,uA. The structures, fabricated by molecular-beam epitaxy, are self-aligned, self-isolated, and minimize electrical and optical losses. Internal quantum efficiencies are-83% and internal losses are 4.2 cm I. Characteristic temperatures of-2X K, and an increase in threshold current and lasing wavelength under extermally applied stress changing from compressive to tensile conditions, show that the major determinants of lasing threshold are density of states and optical losses.