Semiconductor device fabrication

Semiconductor device fabrication is the process used to create the integrated circuits that are present in everyday electrical and electronic devices. It is a multiple-step sequence of photo lithographic and chemical processing steps during which electronic circuits are gradually created on a wafer made of pure semiconducting material. Silicon is almost always used, but various compound semiconductors are used for specialized applications.

The entire manufacturing process, from start to packaged chips ready for shipment, takes six to eight weeks and is performed in highly specialized facilities referred to as fabs.

History

When feature widths were far greater than about 10 micrometres, purity was not the issue that it is today in device manufacturing. As devices became more integrated, cleanrooms became even cleaner. Today, the fabs are pressurized with filtered air to remove even the smallest particles, which could come to rest on the wafers and contribute to defects. The workers in a semiconductor fabrication facility are required to wear cleanroom suits to protect the devices from human contamination.

Node

In general, a node is a localised swelling (a "knot") or a point of intersection (a vertex).

Node may refer to:

In mathematics

In computing and electronics

Freddie Wong

Freddie Wong (born September 13, 1985) is an American filmmaker, musician, VFX artist and competitive gamer. He is a major part of the YouTube channel RocketJump. He is the older brother of actor and YouTuber Jimmy Wong.

Early life

Wong attended Lakeside School in Seattle, Washington. He then attended and graduated from the University of Southern California School of Cinematic Arts. Wong owns and manages Overcrank Media, a Los Angeles-based media production company specializing in feature film and online video content, having produced an independent film titled Bear. Wong met his future collaborator Brandon Laatsch in college.

Career

Wong competed in the World Series of Video Games in Dallas in July 2007. He won first prize in the Guitar Hero 2 competition, playing the song "Less Talk More Rokk" by Freezepop.

During MTV's "Gamer's Week" celebration in November 2007, Freddie appeared as a guest on Total Request Live. Participating in the program with his newly formed band Hellanor Brozevelt, Wong was part of a country-wide search to find the best Rock Band ensemble. After receiving tutelage from well-known rockers Good Charlotte, Brozevelt performed at the Hard Rock Cafe in New York against Chicago-based Carrie Me Home.

Vertex (graph theory)

In mathematics, and more specifically in graph theory, a vertex (plural vertices) or node is the fundamental unit of which graphs are formed: an undirected graph consists of a set of vertices and a set of edges (unordered pairs of vertices), while a directed graph consists of a set of vertices and a set of arcs (ordered pairs of vertices). In a diagram of a graph, a vertex is usually represented by a circle with a label, and an edge is represented by a line or arrow extending from one vertex to another.

From the point of view of graph theory, vertices are treated as featureless and indivisible objects, although they may have additional structure depending on the application from which the graph arises; for instance, a semantic network is a graph in which the vertices represent concepts or classes of objects.

The two vertices forming an edge are said to be the endpoints of this edge, and the edge is said to be incident to the vertices. A vertex w is said to be adjacent to another vertex v if the graph contains an edge (v,w). The neighborhood of a vertex v is an induced subgraph of the graph, formed by all vertices adjacent to v.