news on Semiconductor Java Applets

JAS Website News (NSF Fastlane Project Report System)
(your comments to wie@eng.buffalo.edu)

August 2003: Interactive 3D data visualization applet is in service. This 'first' applet in 3D visualization visualizes a function or a 3-dimensional high-resolution x-ray diffraction data on AlGaAs/GaAs sample or a ZnCdSe/GaAs sample.
July 2003: The Semiconductor Applet Service has been awarded the 2003 MERLOT CLASSICS AWARD for Engineering discipline.
February 2003: A new machine is working as the backup server now, but under the same name, JAS.
February 2003: Power outage, twice in 5 days, costed our rather dependable backup server, jas.eng.buffalo.edu, which seems to have developed HD failure. Until we bring up JAS, we shall use JAS21 as a temporary backup server.
November 2002: The Internet Scout Project has selected our site--The Semiconductor Applet Service for inclusion in the National Science Digital Library Report for Math, Engineering, and Technology (October 25, 2002). Here is the criteria of this report and the report of our site.
October 2002: New virtual lab worksheets added ... Common-emitter amplifier, common-base amplifier, and common-collector (emitter-follower) amplifier circuits analysis applets.
October 2002: Applets improved ... Greatly refined and improved is the "Crystal Structure and 14 Bravais Lattices" applet. Also, errors and software bugs in the "Single-Stage BJT Amplifier Circuits applet" have been fixed.
October 2002: A new Applet entitled "Crystal Structure and 14 Bravais Lattices" has been added. This applet is a most ambitious crystal structure applet. You can create just about any crystal (using the 14 Bravais lattices and any crystal from the 7 crystal systems) and view them in 3D from any viewing angle.
September 2002: A new Applet entitled "PIN Junction Space Charge profile and Electric Field profile" has been added.
September 2002: A new Applet entitled "Solar cell design calculation" has been added.
September 2002: A new Applet entitled "PIN Junction Energy Band Diagram" has been added. This applet is similar to the energy band diagram drawing applet of PN junction, but for PIN junction.
September 2002: A new Applet entitled "CMOS Inverter Fabrication" has been added. This applet walks you through the CMOS fabrication steps using a cross-sectional view, animation, and explanation text view. At the end of the fab steps, a planar 'layout' view also appears in the applet.
August 2002: Debugged -- quite a few, minor problems are fixed in the Single-Stage BJT Amplifier Circuits applet and in the Single-Stage MOSFET Amplifier Circuits applet. Virtual lab worksheets for these two (actually four amplifier circuits in each applet) applets are presently being written and will be available for Fall 2002 semester.
August 2002: VirtualLab worksheets -- Virtual Laboratory Worksheets are added for two Bipolar Transistor visualization applets, "Current Components in BJT Virtual Lab" and "Base Width vs. Diffusion Length Virtual Lab".
July 2002: A new crystal unitcell applet entitled "hcp Crystal Unit Cell Applet" has been added. This applet visualizes the Hexagonal Closed Packed structure in 3D.
July 2002: Virtual Laboratory Worksheets are added for the applets entitled"Carrier Concentration and Fermi Level", "PN Junction Diode and Energy Band Diagram", "PN Junction Diode and Energy Band Diagram, ver.3", and "PN Junction Diode under Bias". These virtual lab worksheets are best used in a Computer Laboratory class or recitation for a Junior-level Electrical Engineering Undergraduate course.
June 2002: The existing applet entitled Fermi Level and Carrier Concentration Applet has been completed for temperature-dependence, showing the impurity states, etc. This applet is in THE final form now.
June 2002: A new applet entitled Circuit models of four basic amplifiers is in service. This applet is to visualize the basic building blocks of an amplifier circuit; understand the circuit models of the four different types of amplifiers; and be able to do a simple calculation of the amplifier Gain.
April 2002: A new applet -- Different load types in an IC Amplifier Circuit -- is in service. An analog amplifier circuit in Integrated Circuits (IC) uses a MOSFET transistor as the load device instead of a resistor. This applet discusses and visualizes the concepts.
April 2002: How To Print The Applet Page --In the computer lab (virtual lab) reports and homework assignments a printout of the applet page is frequently needed. Applets do not print directly. The how-to-print-applet instruction is added to each applet page.
February 2002: The final improvment of Framework for Visual Simulation Applets is nearly completed where the two applets (single-stage MOSFET amps, and single-stage BJT amps) are the direct examples of applets that can be developed with the Framework. We are currently working on another applet example and a sinple step-by-step usage tutorial for this Framework. When the documentation and tutorial are completed, we shall release the Framework from this site for free use by educators and developers.
February 2002: Single-stage MOSFET amplifier circuit analysis applet has been added. This applet, along with the single-stage BJT amplifier analysis applet, was developed by using the Framework for visual simulation applets. Also, the performance of the single-stage BJT amplifier applet has been significantly improved.
February 2002: (Important info about the future of Semiconductor Applets Serivce) Our current funding that supported Graduate Assistants to help develop and maintain the Semiconductor Applets and the JAS website is due to expire within this year. Our next options are: (Option-1) Securing industrial support (for two Graduate Assistants plus other expenses) for the development/maintenance of applets and for our free websites, JAS and JAS2; or (Option-2) Only the local versions (approximately $150 per single user license) made available and the free web service discontinued. Realization of the option-1 within the next six months will prevent us from adopting the option-2.
January 2002: Single-stage BJT amplifier circuit applet has been added. This is the first version with Common-Emiiter (with or without Re), Common-Base and Common-Collector configurations.
December 2001: The local version of Semiconductor Applets can be ordered at a nominal cost.
November 2001: Applet corrections -- Corrected are the current gain inconsistency (alpha and beta) in the BJT Base simulation applet and the background color (gray) problem in the NMOSFET Fabrication applet for some browsers.
November 2001: The MERLOT Physics team has completed Peer Review on several semiconductor applets as listed below. External peer reviews and other similar evaluations of materials on this site will be linked from each applet's FEEDBACK page.

The Semiconductor Applet Service general website: MERLOT peer review
Localized States and Fermi Function applet: MERLOT peer review
Fermi Energy, DOS, and Semiconductor Statistics applet: MERLOT peer review
Haynes-Shockley (Drift, Diffusion, and Recombination) applet: MERLOT peer review
Zincblende/Diamond Crystal Structure applet: MERLOT peer review

November 2001: The Worksheet pages of many applets are being modified to include directed, step-by-step instructions. Many of these were used in the computer lab recitation of a Junior-level electrical engineering undergraduate course. These worksheets are appropriate homework assignments also, in which case the students can print out the accompanying Excel spreadsheets, fill in and hand in for grading. More worksheets will be included over time. Most are first-time drafts and may contain errors/typos. Feedback will be welcomed. Some examples of these include:

The BJT Switching applet worksheet
Common-Emitter BJT Amplifier Biasing applet worksheet
The PN Juncion Diode applet worksheet
BJT Base Simulation applet worksheet
BJT Wide vs. Narrow Base applet worksheet.
MOSFET, enhancement-mode devices, operating mode vs. Vg (channel On/OFF); vs. Vgs and Vgd (Pinch-off at Drain-end); and vs. Vgs and Vds (Triode/Saturation).

September 2001: Several new Graduate assistants are being trained to improve and add resources at this site.
September 2001: This site has been added to the UK's PSIgate (http://www.psigate.ac.uk). Use key words "semiconductor applets" in their search function. "Your website has been catalogued for inclusion in PSIgate. PSIgate (http://www.psigate.ac.uk) is the physical sciences information gateway of the UK's Resource Discovery Network (RDN), providing access to high quality Internet science resources in the following areas: astronomy, chemistry, earth sciences, physics, aspects of materials science, and science history and policy. The information provided for each site includes the title, URL, keywords and a description written by one of our subject specialists."
June 2001: Our Semiconductor Applets website is in the Science magazine, June 8th issue, in the NetWatch column. You can try to view it online; it may require subscription though.
June 2001: Web-Based Simulation of Microelectronic Devices (WebSimMicro) -- The first (tentative) system is now in service at jas7.eng.buffalo.edu. This system allows users to simulate MOSFET devices and Bipolar Transistors. For more info, click here.
May 2001: Java-Extension Framework for Web-based Simulation -- A Java extension Framework has been designed and developed to enable an easy extension of legacy simulation programs to the web environment. This Framework is a product of a Thesis entitled "WEB-BASED SIMULATION OF MICROELECTRONIC DEVICES AND FRAMEWORK DESIGN". For more information on Java-extension framework, click here.
May 2001: Software Framework for Educational Java Applets -- Tutorial and API are available for preview. For more info, click here.
Feb. 2001: A twelve applet sequence is complete for the simulation of Semiconductor Memory architecture and component devices. Part of this set served as basis for analysis and design of Applet Framework, and the remainder of this set was developed directly from the Framework itself.
Jan. 2001: Framework for Visual SimulationApplets-- A Thesis entitled "DESIGN, IMPLEMENTATION AND APPLICATION OF FRAMEWORK IN JAVA EDUCATIONAL APPLETS". [A Framework is a development tool with reusable architectural designs and reusable software components, specific to a given application domain. The application domain here is the interactive animated visual simulation applets. This Framework is useful for writing Java applets quickly, that has guaranteed performance and interactivity, for visual simulation of scientific and engineering problems.] Educators and engineers with less experience in Object-Oriented software design or Java programming could benefit from this Framework in developing own applets. A first draft-tutorial on how to use this Framework for applet development is ready.
Jan. 2001: We have a backlog of CD-ROM requests from many US Institutions and from many foreign Institutions. We plan to process the US requests within the next couple of weeks. International requests could take a bit more time. Our apologies for the delay.
Oct. 2000: First round of CDROM dissemination is completed. Further distribution will take place upon receipt of individual requests.
Aug. 22, 2000: We shall be mailing the CDs Tomorrow (8/22/00) to the U.S. faculty members who have sent the license agreement form. (our apology for the delay -- we had to revise and correct many errors.) We received several requests from abroad. We shall look to mail these soon (if the shipping cost is acceptable).
Aug.11, 2000: We are close to finishing the preparation of the site for burning CD-R's. Have added many new text files (still need to add some more), and added a few more applets. I will be back on Aug.16 and try to complete the preparation and will immediately start writing to CD-R's. First round of mailing CD-R's will start around August 18 - 22.
June-August 2000: CD-ROM Dissemination --- We are producing a beta version CD-ROM of this website for dissemination and evaluation. This version will be provided, free of charge, to University Faculty members (in US Universities) involved in teaching related courses, The CD-ROM is provided in conjunction with our dissemination and assessment efforts. To receive a CD-ROM containing all the applets, please fill out the Licence Agreement Form and fax it back to us. The CD-ROMs will be mailed to you near the end of July 2000, in time for Fall semester.
March-May 2000: Several new applets have been added.
Feb. 2000: CD-ReWritable Simulation applet is in service now.
Jan & Feb 2000: New component applets for consumer products are in service now --- i) the Six-Transistor SRAM Cell operation; ii) Row-Decoder simulation for Memory architecture; and iii) CD-Recordable simulation. Improved is the applet that compares Maxwell-Boltzman approxmiation to the exact Fermi-Dirac calculation of carrier concentration vs. Fermi level.
December 1999: Another product-level applet is now available for review. This applet, Integrated-Optic CD-ROM Readhead Applet (click here for IE5.0 users, and here for Netscape4.7 users), demonstrates and simulates the operation of CD-ROM read process. This is the second of consumer-product applets which will serve as the top-level entry point into the underlying component subsystem, device, or materials applets which are under development at the present time. The first consumer-product applet was the CMOS memory architecture applet which was developed earlier.
December 1999: (1) A commercial wireless web access device Qubit^TM. Scheduled to be released in early 2000, it is a design based on National Semi's WebPAD. Enables web access for full multimedia viewing via 56K modem, cable modem, or ethernet port. Initial pricing planned at under $400. (2) Wired Info Appliance,i-opener^TM. Built-in 56kbps Modem, sized 9.33"x12"x3.5", priced at $199.
November 1999: Portable web access device WebPAD^TM and educational java applets -- National Semiconductor recently announced the reference platform, so-called Geode^TM WebPAD^TM, which is a portable web access device with a size 8-1/2" x 11" x 1.75". With now so much potential demand on such a consumer device (e.g., access to email, ecommerce, daily news, stock quote, ...) such device will of no doubt be priced low enough for every student to afford, just like yesterday's calculator. This means that the educational java applets will be 'one-step away', just like textbooks and lecture notes. The technology is advancing fast enough that students will soon use educational applets as frequently as textbooks and lecture notes and our effort of applet development will be well rewarded.
November 1999: MOS Memory Simulation Applet. It provides visual simulations of Read or Write operation, and allows users to interactively perform Read from or Write to the 8x8 MOS Memory Cell array. Written in Java1.1 (requires IE5.0 or Netscape4.7 or newer).
Re: Web Browser versions to run applets.

August 1999: The three applets are finally ready. These applets took much longer than we originally expected. The BJT switching characteristic applet was very complex and took over three months to develop, leading to many reusable library classes. No supplementary web pages have been written yet. We would welcome any comments and feedbacks on these: (1) The Bipolar Transistor Switching applet; (2) The Capacitance-Voltage of PN Junctions; and (3) Current-Voltage calculator of PN and Schottky Diodes. Written in Java1.1, they run in IE5 or recent versions of Netscape.
May 1999: The PN diode CV characteristic applet is well under progress. A new applet, the dynamic switching characteristics of BJT, is being analyzed and designed.
April 1999: Current projects -- i) capacitance-voltage of PN junction; and ii) architectural design of visual circuit simulator based in Java. The goal of the second project is to produce a library or platform that will enable SPICE-like circuit simulation over the internet, with an added capability of visual interaction and presentation, a unique feature enabled by Java.
April 1999: During the Summer of 1999, most of the text pages for every applet will be filled.
April 1999: The Bipolar Transistor applets has been corrected for the base-emitter bias range and for the base doping level. We wish to acknowledge the interaction with Dr. Bob Biard of Honeywell on the BJT applets.
March 1999: A new applet on Bipolar Junction Transistor -- Base simulation -- is available.
March 1999: Regarding Solid State Applet Webservers --- 1) jas2.eng.buffalo.edu is the development server, always current and always up-to-date; 2) jas.eng.buffalo.edu is a permanent, dedicated server, only serving the solid state applets, full-time; 3) jas5.eng.buffalo.edu is a back-up server in case the first two are down or inaccessible.
March 1999: Next applet to be on-line is the Current components moving in and out of the base region of a BJT as the bias at the two junctions is changed.
March 1999: Our recent analysis of the web access data showed that the most frequently accessing clients are U.C. Berkeley and Stanford for University users, and Texas Instrument, Samsung and Motorola for Industry users. The applet web pages were accessed at about 1,000 pages a day.
March 1999: The applet template design has changed a bit. This makes the pop-up window of the text pages a trimmed-down window.
March 1999: A Bipolar transistor applet is now on line. It shows a minority carrier concentration profile in the base region, the slope of carrier concentration at the emitter and collector junctions and the related current densities where the base width is a user-controlled parameter. The key concept to learn is how many of the carriers injected at the Emitter junction are collected at collector junction as controlled by the relative sizes of the base width and the minority carrier diffusion length in the base.