Reliability Comparison of Al2O3 and HfSiON for use as Interpoly Dielectric in Flash Arrays

Use of Al2O3 as inter-poly dielectric in a production proven 130 nm embedded Flash technology

“…Here, Al 2 O 3 is a good candidate [2], being a well-known high-k material that has already reached the required level of maturity [3,4]. Recently, integration and data retention were demonstrated on single cells [5] and small arrays [6]. In this paper, we present the successful integration of Al 2 O 3 as an IPD material into a qualified embedded Flash process using a 2 Mb memory array as demonstrator.…”

Improved Retention for a Al2O3 IPD Embedded Flash Cell without Top-Oxide

“…Successful integration and data retention have already been demonstrated on single-cells [4] and small 26kbit arrays [5], and more recently by us on 2Mb arrays [1,2]. In reference 1, we reported data for several high-k IPD constructions with different bottom oxide and Al 2 O 3 thicknesses and indicated that 4nm of bottom oxide was required to obtain sufficient retention.…”

“…Here, Al 2 O 3 is a good candidate, being a well known highk material that has already reached the required level of maturity [3][4][5]. Successful integration and data retention have already been demonstrated on single-cells [4] and small 26kbit arrays [5], and more recently by us on 2Mb arrays [1,2].…”

A Technique to Extract High-$k$ IPD Stack-Layer Thicknesses From $C$– $V$ Measurements

“…Nevertheless, NVM devices based on floating-gate (FG) concept are still very attractive for their performances and reliability at high temperatures despite some scaling-limiting factors like the high voltages required for program/erase (P/E) operations [3]. High-k interpoly dielectrics (IPDs) have been introduced to increase FG to control-gate (CG) coupling [4], thus allowing to reduce P/E voltages. Unfortunately, compared with standard IPD stacks, high-k dielectrics like HfO 2 , HfSiON, and Al 2 O 3 have generally lower tunnel barriers and high defect densities, that can threaten data retention [5].…”