Growth
| Growth | |
|---|---|
 Schematic of principal elements of MBE[1] | |
| Technology Details | |
| Other Names | Growth, MBE, Epitaxy, Epitaxial growth |
| Technology | Deposition |
| Equipment | List of growth equipment |
| Materials | %Optional materials processed% |
 Warning: | This page has not been released yet. |
Growth or Molecular beam epitaxy (MBE) is a technique for growing thin epitaxial films of semiconductors, metals, and insulators. In MBE, thin films crystallize through reactions between thermal-energy molecular or atomic beams of constituent elements and a substrate surface that is maintained at an elevated temperature in an ultrahigh vacuum chamber.
Contents
Method of operation
In MBE, a heated substrate is placed in an ultrahigh vacuum (~1e-11 Torr). The substrate is in the line of sight of streams of atoms from heated cells that contain the elements to be grown. These atomic streams impinge on the surface of the substrate creating layers with a structure that is controlled by the crystal structure of the substrate, the thermodynamics of the constituents, and the sample temperature. This technique is the most sophisticated form of PVD. The deposition rate of MBE is very low (about 1 μm/hr or 1 monolayer per second), and considerable attention is devoted to in-situ material characterization to obtain high-purity epitaxial layers. Fast-acting shutters control the deposition. At most, a couple atomic layers of material are released between the opening and closing of the shutters. The low deposition rate gives better control over the film thickness. MBE growth also allows for precise control of the doping profile on an atomic level. With molecular beam epitaxy, virtually any device structure can be grown. The limitations of this technique are in volume manufacturing and cost. The ultrahigh vacuum requirements make operation very expensive.
A big advantage of MBE is the ability to utilize in-growth surface characterization techniques. In particular, reflection high energy electron diffraction (RHEED) allows direct measurements of the surface structure of the substrate and the grown epitaxial layer. It also allows observation of the dynamics of MBE growth.
Applications
Epitaxially grown substrates are used in Electronic Devices Applications such as high electron mobility devices, Optoelectronic Devices such as quantum well lasers and quantum cascade lasers, and Magnetic Semiconductors and Spintronics Devices such as magnetoresistive memory and spin-based quantum computers.
Parameters
Here we describe what parameters are of importance in this technology (e.g. power, temperature...). May not be relevant to some technologies.
Parameter 1
You may want to make a separate sub-page or article specifically for a parameter if this is longer than, say a paragraph or two. If not, get rid of the {{main|xyz}} below the heading.
Subtechnology 1
Describe any sub-technologies of this technology.
Materials
Optional description of materials that can be processed by technology. I think the best example of where this comes in handy would be with LPCVD describing the difference between HTO and LTO.
Equipment
If this is a "main category" for equipment (i.e. you categorized that equipment page to be this technology), you should list the equipment here with a brief description of that tool's capabilities. Seriously, though, just check out the RIE page.
Equipment 1
Brief description of that piece of equipment.
Complete tool list
See also
Other related wiki pages
References
- ↑ Puebla, Jorge. (2012). Spin phenomena in semiconductor quantum dots.
Further reading
- Other stuff, e.g. technology workshop slides
- External links (can be in another section below, if appropriate)
