Spring01 reduce risk300

Page 1

S

P

300 mm

E

C

I

A

L

F

O

C

U

S

Reducing Risk at 300 mm By David J. Hemker, Ph.D., Lam Research Corporation

Drivers for the 300 mm transition are the need to reduce costs and increase capital productivity—not the need for new technical capability, although traditional design shrinks will occur concurrently. While the industry continually pushes the limits of technology, it is extremely adverse to risk. This article discusses the means to mitigate the risks of equipment procurement during the 300 mm transition.

Introduction

Minimizing Investment Risk

At 300 mm, IC manufacturers must concurrently manage increased wafer costs often accompanied by smaller geometries implemented in new materials. These tasks, combined with shrinking margins and fierce competition, create a situation where risk and development costs must be minimized in order to justify the transition from 200 mm wafers.

To minimize investment risk, manufacturers must consider initial equipment costs and other areas that are equally important over the long term. These include the state of the industry’s transition to 300 mm wafers and the production readiness of individual tools. Some factors that minimize risk are widely recognized and grouped by the industry under the term “overall equipment effectiveness’ (OEE), and each of these should be evaluated along with yield, which must be high to make the transition feasible. The following discusses each of the factors that reduce investment risk in detail.

Several areas need to be addressed to reduce the 300 mm transition risk. Delivering more mature equipment at release with fully developed 300 mm processes that leverage 200 mm experience is one way. This allows fabs to ramp quickly—without needing to debug new equipment or rework processes. Offering improved uptime and higher reliability on new tools is also important. Since manufacturers are targeting the same percent yield of good die at 300 mm as they currently achieve at 200 mm, addressing process uniformity and edge exclusion issues will be essential. Foundries and multi-product manufacturers will need application flexibility. Finally, minimizing 300 mm process equipment footprint and ensuring adaptability to future processes will be important. We can summarize all these requirements under three categories that must be managed to successfully transition to 300 mm: investment risk, technical risk, and obsolescence risk.

Equipment costs The economics of 300 mm equipment costs were debated back in 1998 in a two-part article by authors at Intel and Lam 1. Representing the IC manufacturers’ viewpoint, Intel considered the increase in capital (the relative cost of tools normalized by wafer output) and the increase in footprint (the relative size of the factory, similarly normalized) while transitioning from 200 mm to 300 mm on a factory-wide basis. From Intel’s viewpoint, in order to be economical, the increase in capital costs would have to be 1.3x or less, and the footprint should not increase. At Lam, we agree that, in the aggregate, 300 mm equipment costs may average a 1.3x increase over 200 mm equivalent equipment. However, to simply apply a 1.3x cost multiplier across all equipment ignores the possibility of broad capability differences among equipment offerings. Additions such as advanced factory automation and in situ sensors may not be available on all tools within an equipment category. Such capabilities should be considered in the cost equation since they impact productivity and yield, which affect overall Spring 2001

Yield Management Solutions

35


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.
Spring01 reduce risk300 by KLA Corporation - Issuu