SANDISK AND TOSHIBA are teaming up in a quest to finally bring some long awaited re-writeable 3D memory to market.

The news broke as Sandisk filed a U.S. stock market regulator report late on Tuesday, which notes that the two firms will contribute to and cross license technology for 3D memory chip development and production. About time too.

The 3D memory chip dream actually goes way back, with a company called Matrix already having discovered how to stack memory arrays vertically and not just horizontally, back in 2001. The discovery, which had incredible potential for lowering costs and boosting the amounts of memory able to be stored on a chip significantly, sadly never really took off, despite Matrix’s partnership with Taiwan Semiconductor Manufacturing (TSMC).

Matrix was snapped up by Sandisk, whose main product is NAND flash memory, in 2005, but it seems to have taken the company three years to come up with some sort of plan to finally bring the promising technology into the world. Matrix’s original attempt at producing the technology only yielded non rewritable chips, whereas this new joint venture aims at creating rewritable ones.

Toshiba will apparently pay licensing fees to SanDisk for the privelage of being part of the venture, according to the SanDisk statement.

It’s not the first time Toshiba have developed rewriteable 3D flash memory chips either. Several years ago the company came out with some working samples dubbed BiCS (Bit Cost Memory), but these too never caught on.

But now, even with the combined power of the two companies and their know-how, it could still take three or four years for product to tip up which actually has the promise of displacing NAND from its throne. This is because 3D memory chips are quite bothersome to manufacture at high yields.

Still, with the promise that the new chips will be able to store information significantly longer, (100 years some say), and lower costs, 3D memory is worth keeping in mind. µ