Back in 2010 I published an article in the Nanotechnology Law &Business Journal (link
) discussing the business prospects of memristive electronics. I recently updated the data from this article to be current as of Jan 01, 2012 including data sorted by patent issue year, claimed application (memory, logic/computing, or neuromorphics) and claimed material (phase change, solid electrolyte, metal oxide, or molecular/polymer). The updated data is available at this link
Below is the list of the top 10 patent holding companies along with the primary class of material covered by the patents.
1) Samsung (387 US patents, phase change)
2) Micron (371 US patents, solid electrolyte)
3) Macronix (171 US patents, phase change)
4) Ovonyx (165 US patents, phase change)
5) IBM (126 US patents phase change)
6) HP (108 US patents, molecular)
7) Toshiba (108 US patents, metal oxide)
8) Sharp (107 US patents, metal oxide)
9) Intel (89 US patents, phase change)
10) Qimonda (88 US patents, phase change)
It is notable that the material covered by these patents may not necessarily be the same material that these companies are actually pursuing. For example, Micron seems to be committed to phase change memory rather than the solid electrolyte memory described in the bulk of their patents (link
). Also, as I have mentioned in this blog before, HP and Hynix are working on metal oxide ReRAM which HP is claiming as the fabled "missing memristor" of Leon Chua. Most of HP's memory resistor patents focus on using molecular materials for resistance switching and Hynix Semiconductor (#13 on the list) have almost all of their patents (62/71) dedicated to phase change material. Meanwhile, Samsung (e.g. US Patent 7417271
) and Sharp (e.g. US Patent 7796416
) hold the bulk of the metal oxide patents which HP and Hynix would require to commercialize their "memristor".
It is curious to me that Hynix is working towards manufacturing a form of ReRAM that, if successful, will render most of their phase change memory resistor patents useless. If I were cynical I would almost think that someone at Hynix were working behind the scenes (perhaps with other of the companies heavily invested in phase change memory) to screw over HP in 2013.
A spreadsheet containing the complete patent data is available by sending an E-mail to firstname.lastname@example.org including the subject “memresistor patents”.