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.
A technique for simultaneous definition of two metal levels in the fabrication of a semiconductor is shown that will produce a wiring level with a self-aligned stud level with one exposure.
English (United States)
This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately
93% of the total text.
Page 1 of 2
Simultaneous Definition of Two or More Patterns With One Multilevel Mask
A technique for simultaneous definition of two metal levels in the fabrication
of a semiconductor is shown that will produce a wiring level with a self-aligned
stud level with one exposure.
A double level image is transferred into a metal film(s) making up two metal
levels, i.e., the horizontal wiring level and the vertical stud level. A photoresist
layer is formed having a thin-thick pattern, as shown in Fig. 1. The dark layers
are tungsten, and the hatched layers are aluminum/copper. As shown in Fig. 2,
the upper tungsten layer is etched in an etchant that does not attack the
photoresist. This etch stops at the tungsten aluminum/copper interface. Then
another etch is carried out to etch the aluminum/copper in an etchant that does
attack the photoresist without attacking tungsten. As shown in Fig. 3, this has the
effect of transferring the thin resist profile into the aluminum/copper layer. Then
the first etchant is used again to attack the exposed tungsten shown in Fig. 4,
and the aluminum/copper is etched again (the tungsten serving as the mask
when the photoresist is completely eroded), as in Fig. 5.
The process sequence described defines two levels of metal, i.e., the wiring
level and the stud level, or else a thick metal (low resistance) or a thin metal (low
capacitance) structure. The relative absolute thickness of the bottom metal and
the top metal is determined by the meta...