Faculty Innovators

T.P. Ma

Building Ever-Greater Memory Capacity for Ever-Smaller Digital Devices

When you buy a laptop, you get to decide how much memory to pack into your computer. The same kind of memory, known as DRAM (dynamic random access memory), is in your cell phone or PC.

As consumers expect lighter products with greater memory, industry faces a mounting challenge to fit the more powerful memory devices — including a transistor and a storage capacitor — into smaller spaces.

Enter T.P. Ma, a Yale electrical engineering professor whose work is known to virtually every semi-conductor and computer hardware company in the world. One of his inventions is an improved DRAM that major corporations see as a promising technology to solve this problem.

His invention eliminated the need for a storage capacitor; it’s built into the transistor, thus solving the space problem. It also dramatically increases the intervals between which the memory has to be refreshed — another major advance. Yale has patented the technology, and Ma expects it will be a couple of years before it arrives on the market.

“Several major companies are talking to us and will want to do some prototyping,” he said. “What we have done on the university scale they will want to do on the demonstration scale, for production.”

Ma has served as principal investigator on joint research and development projects with numerous companies. They include Motorola, General Electric, Hughes, Rockwell, Phillips, Siemens, Hitachi, Toshiba, Mitsubishi, Intel and IBM, where Ma worked for three years after receiving his Yale doctorate. His students have gone on to leadership roles at high-technology companies.

He first arrived at Yale as a graduate student from Taiwan, not because of some grand plan but because of the vagaries of graduate school applications. Completing required military service, he had little time to write essays — in English — for his applications. Other top schools called for five-page essays, but Yale asked for only two pages. Thus, Yale became his first choice, quipped Ma.

At Yale, Ma’s earlier research papers helped lay the foundation for flash memory, which can be electrically erased and reprogrammed in many devices.

He recently won the Connecticut Medal of Technology, the state’s highest honor for technological achievement. In bestowing the award, the chair of the board of governors of higher education said it’s not often that basic academic research leads to widespread applications: “But the next time you answer your cell phone, take a digital picture, or tune into your iPod, know that its flash memory is in large part made possible by the pioneering work of T.P. Ma.”