Mechanism of Depletion-Mode TDDB for 4H-SiC MOS Structure
Mechanism of Depletion-Mode TDDB for 4H-SiC MOS Structure
复制标题
4H-SiC MOS结构的耗尽型TDDB机制
DOI：
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发表时间：
2017
影响因子：
2
通讯作者：
S. Yamakawa
中科院分区：
文献类型：
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作者：
Tomokatsu Watanabe;S. Hino;T. Iwamatsu;S. Tomohisa;S. Yamakawa
利用高压直流偏压耗尽的n型4H-SiC MOS电容器，研究了耗尽模式时变介质击穿（DM-TDDB）机理。在DM-TDDB应力作用下，电流测量结果中出现了氧化物/SiC界面下的空穴生成及其向氧化物中的注入。寿命分布明显分为两组：分解时间较短和较长（<inline-formula> < text -math notation="LaTeX">${t}_{mathbf {BD}} $ </ text -math></inline-formula>）。较短的<inline-formula> < text -math符号="LaTeX">${t}_{mathbf {BD}} $ </ text -math></inline-formula> $ </ text -math符号="LaTeX">${t}_{mathbf {BD}} $ </ text -math></inline-formula>的击穿点位于4H-SiC的线位错（TD）附近，而较长的<inline-formula> < text -math符号="LaTeX">${t}_{mathbf {BD}} $ </ text -math></inline-formula>的击穿点不包含位错。对于较长的<inline-formula> < text -math notation="LaTeX">${t}_{mathbf {BD}} $ </ text -math></inline-formula>，在503 K时，随着电势下降（<inline-formula> < text -math notation="LaTeX">${Q}_{mathbf {BD}} $ </ text -math></inline-formula>）的增加（<inline-formula> < text -math notation="LaTeX">${V}_{mathbf {SiC}} $ </ text -math></inline-formula>），击穿电荷（<inline-formula> < text -math notation="LaTeX">${Q}_{mathbf {BD}} $ </ text -math></inline-formula>）从大约4.5 C/cm下降到0.1 C/cm<inline-formula> < text -math notation="LaTeX">$^{2}$ </ text -math></inline-formula>)，表明高能空穴注入降低了寿命。对于较短的<inline-formula> < text -math符号="LaTeX">${t} _{mathbf {BD}}$ </ text -math></inline-formula>，假定TD诱导了来自较深枯竭区域的额外热孔注入到局部氧化层，从而沉淀出渗流路径地层。
The depletion-mode time-dependent dielectric breakdown (DM-TDDB) mechanism was investigated with n-type 4H-SiC MOS capacitors depleted by high-voltage dc bias. Under the DM-TDDB stress, the hole generation beneath the oxide/SiC interface and its injection into the oxide appeared in the current measurement results. The lifetime distribution was clearly divided into two groups: shorter and longer time to breakdown (<inline-formula> <tex-math notation="LaTeX">${t}_{mathbf {BD}} $ </tex-math></inline-formula>). The breakdown point for the shorter <inline-formula> <tex-math notation="LaTeX">${t}_{mathbf {BD}} $ </tex-math></inline-formula> was located close to a threading dislocation (TD) of the 4H-SiC, whereas the capacitors for the longer <inline-formula> <tex-math notation="LaTeX">${t}_{mathbf {BD}} $ </tex-math></inline-formula> contained no dislocation. For the longer <inline-formula> <tex-math notation="LaTeX">${t}_{mathbf {BD}} $ </tex-math></inline-formula>, the charge-to-breakdown (<inline-formula> <tex-math notation="LaTeX">${Q}_{mathbf {BD}} $ </tex-math></inline-formula>) decreased from approximately 4.5 to 0.1 C/cm<inline-formula> <tex-math notation="LaTeX">$^{2}$ </tex-math></inline-formula> with an increase in the electric potential drop (<inline-formula> <tex-math notation="LaTeX">${V}_{mathbf {SiC}} $ </tex-math></inline-formula>) below the interface at 503 K, demonstrating that the high-energy-hole injection lowers the lifetime. For the shorter <inline-formula> <tex-math notation="LaTeX">${t} _{mathbf {BD}}$ </tex-math></inline-formula>, the TD was presumed to induce the additional hot-hole injection from the deeper depletion region into the local oxide and thereby precipitate the percolation path formation.