Abstract Thin films of the Group IV materials silicon and germanium are produced in the range of 2.5 to 25 nm thick from nanocrystal precursors. According to the invention a solid, continuous film of silicon or germanium is formed by depositing a contiguous layer of nanocrystals of the semi-conductor materials onto a substrate, then heating the layer to a temperature below the bulk melting temperature which is nonetheless adequate to melt the nanocrystals and form a continuous liquid thin film upon cooling. The resulting thin film may be doped or intrinsic. The lower processing temperatures make it possible to form these thin semi-conductor films with less stringent thermal requirements on the underlayers, substrates and other related structures, thus supporting applications in microelectronics, solar conversion and so forth.
A method of forming a solid, continuous film of a Group IV semiconductor material on a surface, comprising the steps of: depositing on the substrate surface a thin, contiguous layer of nanocrystals of the semiconducting material, the size of the nanocrystals being sufficiently small that surface effects contribute to melting temperature; melting the nanocrystals at a temperature below the bulk melting temperature of the semiconductor material in order to form a continuous liquid thin film; and cooling the liquid thin to form a solid thin film.
Claim 2
Independent Claim
86 words
A method of forming a solid, continuous film of a Group IV semiconductor material on a surface, comprising the steps of: depositing on the substrate surface a thin, contiguous layer of nanocrystals of the semiconducting material, the size of the nanocrystals being sufficiently small that surface effects contribute to melting temperature; melting the nanocrystals at a temperature below the bulk melting temperature of the semiconductor material in order to form a continuous liquid thin film; and cooling the liquid thin to form a solid thin film.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein the semiconducting material is silicon.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein the semiconducting material is germanium.
Claim 5
Dependent Claim
18 words
The process of claim 1 wherein the nanocrystals have an average diameter of from 1 to 6 nm.
Claim 6
Dependent Claim
33 words
The method of claim 1 wherein the step of cooling the liquid thin film to form a solid thin film includes forming a thin film in the range of 2.5 to 25 nm.