Thermal Boundary Resistance Measurements for Phase-Change Memory Devices

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Thermal interfaces play a key role in determining the programming energy of phase-change memory (PCM) devices. This letter reports the picosecond thermoreflectance measurements of thermal boundary resistance (TBR) at TiN/GST and Al/TiN interfaces, as well as the intrinsic thermal conductivity measurements of fcc GST between 30 <formula formulatype="inline"><tex Notation="TeX">$^{\circ}\hbox{C}$</tex></formula> and 325 <formula formulatype="inline"><tex Notation="TeX">$^{ \circ}\hbox{C}$</tex></formula>. The TiN/GST TBR decreases with temperature from <formula formulatype="inline"><tex Notation="TeX"> $\sim\!\!\hbox{26}$</tex></formula> to <formula formulatype="inline"><tex Notation="TeX">$\sim\!\!\hbox{18}\ \hbox{m}^{2}\cdot \hbox{K/GW}$</tex></formula>, and the Al/TiN ranges from <formula formulatype="inline"><tex Notation="TeX">$\sim$</tex></formula>7 to 2.4 <formula formulatype="inline"><tex Notation="TeX">$\hbox{m}^{2}\cdot\break\hbox{K/GW}$</tex></formula>. A TBR of 10 <formula formulatype="inline"><tex Notation="TeX">$\hbox{m}^{2}\cdot\hbox{K/GW}$</tex></formula> is equivalent in thermal resistance to <formula formulatype="inline"><tex Notation="TeX">$\sim$</tex></formula>192 nm of TiN. The fcc GST conductivity increases with temperature between <formula formulatype="inline"><tex Notation="TeX">$\sim$</tex></formula>0.44 and 0.59 W/m/K. A detailed understanding of TBR is essential for optimizing the PCM technology. </para>