by Debra Vogler, senior technical editor, Solid State Technology

May 22, 2008 – At the final ConFab 2008 session, a diversity of opinions were presented about whether or not 450mm manufacturing is needed, and if so, how will it be financed — topics hashed out ad infinitum in recent symposia and conferences, including ISMI and ISSM, and SEMICON West. Amid the verbal volleying, however, was proof that a few suppliers and chipmakers are actually taking initial steps to develop tools for 450mm wafer manufacturing. ISMI’s associate director, Joe Draina, reported on the progress being made in a number of areas, including the silicon wafer readiness project, wafer manufacturing infrastructure readiness, and a 450mm factory integration testbed.

The factory integration testbed user group, which meets quarterly with suppliers, seeks to demonstrate and identify challenges in moving silicon from shippers through an EFEM, then returning to a desired FOUP/slot.

450mm factory integration testbed approach. (Source: ISMI)

ISMI is fully staffed (both ISMI and supplier assignees) to take on the testbed project, and lab space has been allocated and prepared for carriers and equipment, Draina said. Additionally, 50 mechanical test wafers are in hand at ISMI with plans to go to 100 by next month. Five thicknesses of wafers have been tested for mechanical properties and interaction with shippers, FOUPs, and wafer handlers, he said. Phased factory integration testing comprises early shippers and fab carriers, wafer handling robots and loadports, and full EFEMs by the end of this year, he indicated. Testing will be aligned to maximize efficiency and be linked with SEMI standards development.

Draina also reported that wafer-manufacturing infrastructure activities are moving ahead, encompassing pullers, crucibles, and DSP polishers. Mechanical test wafers (sintered) started to come in during 2H06. Additionally, CZ single crystal pulling feasibility studies have already been completed with initial wafers expected by the end of this year.

A 450mm Si crystal boule. (Source: ISMI)

Goals of the 450mm silicon wafer readiness project include:

– Assessment of technical feasibility and implementation plans for silicon, inspection and silicon manufacturing infrastructure;
– Validation of 450mm handling wafer and process test grade wafer assumptions; and
– Establishing standards, where needed, on 450mm silicon handling wafer and process test grade wafers.

ISMI has also begun “high-level” engagement with process and metrology equipment suppliers, and has been providing periodic workshops on guidelines and testbed progress to keep interested suppliers informed. Twenty-two individual supplier meetings have either taken place or are scheduled, Draina told attendees, and the group expects to continue briefings at major forums such as SEMICON West, SEMICON Japan, and the ISMI Manufacturing Symposium. — D.V.