The following operators can be used to better focus your queries.
( ) , AND, OR, NOT, W/#
? single char wildcard, not at start
* multi char wildcard, not at start
(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*
This guide provides a more detailed description of the syntax that is supported along with examples.
This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.
Concept Search - What can I type?
For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.
Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.
Polysilicon (Poly) is receiving much attention for use as a contact material for many silicon devices. However, the reliability of Poly is questionable.
English (United States)
This text was extracted from a PDF file.
This is the abbreviated version, containing approximately
95% of the total text.
Page 1 of 1
Method to Avoid the Polysilicon Film Tearing Mechanism
Polysilicon (Poly) is receiving much attention for use as a contact material for
many silicon devices. However, the reliability of Poly is questionable.
Polysilicon films are typically grown by chemical vapor
deposition (CVD) at low temperatures, 600 Degrees -700 Degrees C, in
order to minimize grain size and thereby reduce surface roughness.
After Poly deposition in this temperature range, the grain size is
less than 200 Angstrom. However, the Poly must then undergo several
high temperature treatments (doping, drive in, oxidation, anneals) of
1000 Degrees C or higher. The small grains grow to over 1000
Angstrom with the high temperature treatment. Associated with this
drastic change in grain size are changes in the surface area and
density of the Poly films. Therefore, large shear forces must exist.
In fact, transmission electron microscopy observation made during
grain growth has shown that the Poly films developed tears in places
as a result of recrystallization. Not only is the Poly film itself
rendered defective by this tearing mechanism, but both underlying and
overlying films also receive the transmitted shear forces, causing
further device damage.
To avert this tearing mechanism, the polysilicon film is grown at high CVD
temperatures of 800-1000 Degrees C to yield initially larger grains
(Approximately 1000 Angstrom). Therefore, further processing will not
substantially change the grain size, hence av...