1. What is MOSIS?

1.1. Introduction
  The  MOSIS Service is a prototyping service offering fast-turnaround standard
cell and full-custom VLSI circuit development at very low cost.    Designs  are
combined  on  a single wafer fabrication run.  Therefore, instead of paying for
an entire wafer lot costing between $50,000 and $80,000, MOSIS users  only  pay
for the percentage of silicon that they use, which can be as low as $400.

  For   many   designers,   the   ease   of   access,   quick   turnaround  and
cost-effectiveness  have  afforded   opportunities   for   frequent   prototype
iterations that, without MOSIS, might not even have been considered.

1.2. State-of-the-Art Technologies
  Wafer  fabrication  runs  are scheduled on a regular basis for 2.0, 1.6,
and 1.2 micron double metal CMOS/Bulk technologies and for Gallium Arsenide.
A CMOS/Bulk double poly capacitor option for analog design is also available.

  The MOSIS vendor-base includes multiple fabricators for all technologies, and
prototyping  is  alternated  between  them.    Several sets of design rules are
supported, allowing designs done to MOSIS' own public  domain  scalable  rules,
a set of DoD-developed scalable rules, and a fabricator's own rules to be 
combined on the same wafer fabrication run.  The scalable CMOS rules allow
designers to move from 2.0 to 1.6 and 1.2 micron technologies.

  Those who wish to design for a  multivendor-base  using  the  MOSIS  scalable
rules  have  the benefit of not being tied to a particular vendor, which allows
direct comparison of vendor turnaround, yield and cost. After prototyping, they
can  choose among vendors for production. Other designers prefer to work with a
particular vendor e.g., in order to utilize that vendor's design tools.   MOSIS
offers the option of selecting which fabricator a design will go to.

  MOSIS distributes a DoD-developed standard cell library (2.0 and 1.2 micron).
CAD vendor support is in development for this (CMOSN) library.

1.3. How MOSIS Works
  MOSIS users request information from MOSIS on authorization, technologies and
schedules,  submitting their layout geometry in digital format on magnetic tape
or via electronic mail.  Within weeks, MOSIS  delivers  a  set  of  bonded  and
packaged  integrated  circuits  to  users,  which contain the design exactly as
submitted to MOSIS (see the illustration at the end of this chapter).

  MOSIS  merges  designs  submitted  from  different  organizations  onto   one
multiproject wafer (see photographs at the end of this chapter).  Projects from
the  same  organization  can  also  be  grouped  onto  one   chip,   called   a
multiproject-chip.

  MOSIS  will  fabricate  a  design  on the next available run of the requested
technology, according to a published fabrication schedule.   MOSIS  checks  for
correct  syntax  upon  receipt  of  the  layout  geometry but does not validate
designs.  After aggregating projects for a particular run, MOSIS  writes  tapes
and  sends  them  to  the  maskmaker  for  E-beam phototooling.  Masks are then
delivered to MOSIS for inspection and subsequently forwarded to the appropriate
fabrication line.

1.4. Quality Control
  Mask vendors are required to do an automated inspection and masks are
bought against industry defet density specifications.  MOSIS runs its own
process monitor as well as a yield monitor on every run, buying wafers against
parametric specifications that are checked by both the vendor and MOSIS.  
Information obtained from the yield monitor is maintained in statistical 
control charts to help select vendors and to continuously monitor vendor
quality.

  Once  probed  and  accepted,  the  selected wafers are sent to a packager for
assembly. Chips are wire-bonded according to either a  standard  MOSIS  bonding
map or one designed by the user.  MOSIS packagers are qualified on the basis of
bond pull tests and must follow strict static electricity control procedures in
handling  user's  projects.  MOSIS  requires  that  its  packaging vendors meet
industry visual inspection criteria. Packaged parts are  sent  to  MOSIS  users
with  process  parametric  data  and  SPICE  simulation  parameters  from their
particular wafer lot.

1.5. Background
  MOSIS is an acronym for MOS Implementation System.  The MOSIS Service,  begun
in  1980, provides fabrication services to government contractors, agencies and
university classes under the  sponsorship  of  the  Defense  Advanced  Research
Projects  Agency  (DARPA)  with assistance from the National Science Foundation
(NSF).

  The MOSIS user-base was initially primarily university and government  users.
However, MOSIS' success in serving this group of users led, in recent years, to
a natural expansion into the industrial sector, with a rapidly growing  use  of
MOSIS  by  commercial  companies.  MOSIS foundries have also taken advantage of
the frequent prototype runs for their own needs  as  well  as  those  of  their
clients.

  MOSIS  is  located at the Information Sciences Institute of the University of
Southern California (USC/ISI) in Marina del Rey, California.



                               Table of Contents

1. What is MOSIS?                                                             1

   1.1. Introduction                                                          1
   1.2. State-of-the-Art Technologies                                         1
   1.3. How MOSIS Works                                                       1
   1.4. Quality Control                                                       1
   1.5. Background                                                            1