The Niemeyer-Dolan technique, also called Dolan technique or shadow evaporation technique (the term preferred by its inventor, J. Niemeyer), is a lithographic

Lithography

Lithography is a method for printing using a stone or a metal plate with a completely smooth surface...

 method to create nanometre

Nanometre

A nanometre is a unit of length in the metric system, equal to one billionth of a metre. The name combines the SI prefix nano- with the parent unit name metre .The nanometre is often used to express dimensions on the atomic scale: the diameter...

-sized overlapping structures composed of two or more materials.

A shadow mask

Shadow mask

The shadow mask is one of two major technologies used to manufacture cathode ray tube televisions and computer displays that produce color images. The other approach is aperture grille, better known by its trade name, Trinitron. All early color televisions and the majority of CRT computer monitors...

 for oblique angle evaporation is created on the substrate. Depending on the evaporation angle the shadow image of the mask is projected onto different positions on the substrate. By carefully choosing an individual angle for each material to be deposited, adjacent openings in the mask can be projected on the same spot, creating an overlay of different materials.

Usage

The Niemeyer-Dolan technique can be used to create small nanostructures

Nanostructure

A nanostructure is an object of intermediate size between molecular and microscopic structures.In describing nanostructures it is necessary to differentiate between the number of dimensions on the nanoscale. Nanotextured surfaces have one dimension on the nanoscale, i.e., only the thickness of the...

, such as quantum dots

Quantum dot

A quantum dot is a portion of matter whose excitons are confined in all three spatial dimensions. Consequently, such materials have electronic properties intermediate between those of bulk semiconductors and those of discrete molecules. They were discovered at the beginning of the 1980s by Alexei...

 or tunnel junctions

Tunnel junction

A tunnel junction is any junction between two different materials, where electrons move through the junction by quantum tunneling. Tunnel junctions serve a wide variety of different purposes....

. With a tunnel junction the coulomb blockade

Coulomb blockade

In physics, a Coulomb blockade , named after Charles-Augustin de Coulomb's electrical force, is the increased resistance at small bias voltages of an electronic device comprising at least one low-capacitance tunnel junction. Because of the CB, the resistances of devices are not constant at low bias...

can be observed.