{"id":19342,"date":"2024-03-25T18:18:37","date_gmt":"2024-03-25T18:18:37","guid":{"rendered":"https:\/\/chipedge.com\/?p=19342"},"modified":"2024-03-25T18:18:37","modified_gmt":"2024-03-25T18:18:37","slug":"what-is-a-stick-diagram-in-vlsi","status":"publish","type":"post","link":"https:\/\/chipedge.com\/resources\/what-is-a-stick-diagram-in-vlsi\/","title":{"rendered":"What is a Stick Diagram In VLSI?"},"content":{"rendered":"

What is a Stick Diagram In VLSI?<\/span><\/h2>\n
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A stick diagram in VLSI is a type of diagram that is used to lay out a transistor cell. The devices and conductors are represented by “sticks” or lines in stick diagrams. It is essential to define the direction and metalization of the power supply, ground, input, and output to create the circuit’s architecture. A Stick diagram is a typical approach to symbolic design. Now that we know what a stick diagram is, let us see how this diagram is drawn. Stick Diagram does not include Sizes of the transistors and Wire lengths, Wire Widths and Tub Boundaries.\u00a0<\/span><\/p>\n

How Does A Designer Draw A Stick Diagram?<\/span><\/h2>\n

The designer creates a freehand layout design, using coloured lines to indicate various process layers such as diffusion (p or n), metal, and polysilicon, where the polysilicon layer crosses the diffusion layer. Distribution or poly connections are made by joining metal wires.<\/span><\/p>\n

Design rules serve as a connection of communication between the designer, who specifies needs, and the fabricator, who materializes them. The goal of <\/span>VLSI course<\/span><\/a> is to convert circuit principles to silicon. Stick Diagrams may be used to represent layer information using colour coding. For a depletion mode transistor, implanting inside the thin oxide is required.<\/span><\/p>\n

We need design rules to draw a stick diagram which is the interface between designer and process engineer. Some of the stick diagram rules are:\u00a0<\/span><\/p>\n

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  1. When two or more sticks of the same type cross or touch each other, that represents the electrical contact.<\/span><\/li>\n
  2. When a poly crosses diffusion it represents a transistor.<\/span><\/li>\n
  3. In CMOS a demarcation line is drawn to avoid touching of p-diff with n-diff. All PMOS must lie on one side of the line and all NMOS will have to be on the other side.<\/span><\/li>\n
  4. Design rules allow the translation of circuits into actual geometry in silicon where it interfaces between circuit designer and fabrication engineer.<\/span><\/li>\n<\/ol>\n

    Why Do We Need Stick Diagrams in VLSI?<\/span><\/h2>\n