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.
This article concerns a real-time Photoresist Shelflife Monitor (PSM) for tracking photoresist shelflife as it is affected by storage time and temperature.
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
67% of the total text.
Page 1 of 2
Photoresist Shelflife Monitor
This article concerns a real-time Photoresist Shelflife Monitor (PSM) for
tracking photoresist shelflife as it is affected by storage time and temperature.
Positive photoresists used in semiconductor manufacturing processes
generally suffer a loss of photoactivity, if not kept under refrigeration, due to
storage at too high a temperature for too long a time. Existing functional tests to
establish photoresist adequacy are time consuming and may result in costly
rework when done on a product basis. The real-time monitor described in this
article makes use of a thermocouple, microprocessor and clock/counter system
to record and present the amount of time a photoresist container has spent
above a known critical temperature while in storage.
The drawing is a schematic diagram of a PSM. The thermocouple 1 provides
an input signal (a voltage corresponding to actual container storage temperature)
to the analog-to-digital converter 2 whose digital output is fed, for comparison, to
a predetermined temperature set-point value in the comparator 3. Thermocouple
1 is calibrated by means of the potentiometer control 4. The temperature set-
point value, which is dependent upon the photoresist type, is adjusted by means
of potentiometer control 5. Both components 2 and 3 are incorporated into the
battery-powered microprocessor chip 6, as is the clock/counter 7. The
clock/counter 7 may be activated above (and deactivated below), an established