A Schottky diode needs to be fabricated by deposition of a s

A Schottky diode needs to be fabricated by deposition of a suitable metal on an n-type Si doped at a concentration of 2.33×1014 cm-3 as shown in the figure. Work function of various metals are listed in

                 n-Si

(a) List the metals from the table which can NOT be used to fabricate a Schottky diode. Explain your answer with necessary calculations.

(b) Which metal would you chose to fabricate a Schottky diode with highest

Schottky barrier height? Justify your answer. What would be the built-in potential in that diode?

(c) Draw band diagram of the Schottky diode (mark all energy levels).

Solution

A Schottky diode, also known as a hot carrier diode, is a semiconductor diode which has a low forward voltage drop and a very fast switching action. There is a small voltage drop across the diode terminals when current flows through a diode. A normal diode will have a voltage drop between 0.6 to 1.7 volts, while a Schottky diode voltage drop is usually between 0.15 and 0.45 volts. This lower voltage drop provides better system efficiency and higher switching speed. In a Schottky diode, a semiconductor–metal junction is formed between a semiconductor and a metal, thus creating a Schottky barrier. The N-type semiconductor acts as the cathode and the metal side acts as the anode of the diode. This Schottky barrier results in both a low forward voltage drop and very fast switching.

Types of Schottky Diodes

There are many different kinds of Schottky diodes and at Future Electronics we stock many of the most common types categorized by maximum average rectified current, maximum reverse voltage, maximum reverse current, forward voltage, packaging type and maximum peak current. The parametric filters on our website can help refine your search results depending on the required specifications.

The most common sizes for maximum average rectified current are 70 mA, 100 mA, 200 mA and 1 A. We also carry Schottky diodes with maximum average rectified current as high as 300 A. Forward voltage can range from 280 mV to 430 V, with the most common Schottky diode semiconductor chips having a forward voltage of 800 mV or 1 V.

Schottky Diodes from Future Electronics

Future Electronics has a full selection of Schottky diode chips from several manufacturers that can be used for any circuits that may require a Schottky barrier diode. Simply choose from the Schottky diode technical attributes below and your search results will quickly be narrowed to match your specific Schottky diode application needs.

If you have a preferred brand, we deal with several manufacturers such as NXP, Diodes Inc., ON Semiconductor, ROHM Semiconductor, STMicroelectronics or Vishay, among other manufacturers. You can easily refine your Schottky diode product search results by clicking your preferred Schottky diode brand below from our list of manufacturers.

Applications for Schottky Diodes:

Schottky diodes are useful in voltage clamping applications and prevention of transistor saturation due to the higher current density in the Schottky diode. Also, because of the low forward voltage drop in a Schottky diode, less energy is wasted as heat, therefore making them an efficient choice for applications that are sensitive to efficiency. Because of this, they are used in stand-alone photovoltaic systems in order to prevent batteries from discharging through the solar panels at night as well as in grid-connected systems containing multiple strings connected in parallel. Schottky diodes are also used as rectifiers in switched-mode power supplies.

Choosing the Right Schottky Diode:

When you are looking for the right Schottky diodes, with the FutureElectronics.com parametric search, you can filter the results by various attributes: by Maximum Average Rectified Current (70 uA, 70 mA, 100 mA, 200 mA,…), Maximum Peak Current (200 uA, 600 mA, 1A,…) and Forward Voltage (280 mV to 430 V) to name a few. You will be able to find the right semiconductor chip from several manufacturers that can be used for any other circuits requiring a Schottky barrier diode.

Schottky Diodes in Production Ready Packaging or R&D Quantities

If the quantity of Schottky diodes required is less than a full reel, we offer customers many of our programmable Schottky diode products in tube, tray or individual quantities that will avoid unneeded surplus.

In addition, Future Electronics offers clients a unique bonded inventory program that is designed to eliminate potential problems that may arise from an unpredictable supply of products containing raw metals and products with erratic or long lead times. Talk with your nearest Future Electronics branch and find out more on how you and your company can avoid possible shortages.

metals having values before 5.0 are used in fabrication process

When less power dissipation is desired, a MOSFET and a control circuit can be used instead, in an operation mode known as active rectification.

A super diode consisting of a pn-diode or Schottky diode and an operational amplifier provides an almost perfect diode characteristic due to the effect of negative feedback, although its use is restricted to frequencies the operational amplifier used can handle

i would prefer coblat