低濃度氫氧化氨、雙氧水混合物在深溝渠式記憶體清洗製程之研究

Abstract

本論文研製之低濃度APM（Ammonia (NH4OH ) and hydrogen Peroxide(H2O2) UMUixtures）之清洗液分別清洗溝渠式標準型DRAM（Dynamic Random Access Memory，動態隨機存取記憶體）的DT段製程（deep trench）、STI 段製程（shallow trench isolation）和磊晶裸片（Bare wafer）共三種實驗試片。清洗液測試前二種試片為微塵粒子的移除顆數，第三種試片則測試其表面粗糙度、崩潰電壓（VBD : Breakdown voltage）和崩潰電荷（QBD : Charge to breakdown）。清洗液實驗參數為濃度、溫度及超音波功率。本實驗推論出隨著濃度和溫度的上升，微塵去除的效果上升但表面損傷也大，利用試片C確認晶圓表面的損害程度，在移除效果和可接受損傷範圍中作取捨。本實驗試著降低4~5倍濃度從微塵移除量來看，清除效果並未明顯減少，並從試片C中得知晶圓損傷減少，故減低濃度來進行清洗是可行的。

In this thesis, clean solution of dulite APM（Ammonia (NH4OH ) and hydrogen Peroxide(H2O2) Mixtures）was evaluted to DT（Deep Trench）layer 、STI（Shallow Trench Isolation）layer of standard deep trench type DRAM（Dynamic Random Access Memory）and p-type bare wafer, three kinds of test wafer. Check item in DT and STI test wafer was particle removed counts. Check item in bare wafer were wafer suface roughness、Breakdown voltage （VBD）and Charge to breakdown（QBD）。 Clean solution experiment parameter were solution concentration,temperature and megasonic power. In those experiments, increased concentration and temperature were increased particle remove efficiency,but also damage wafer surface. Used test wafer C to confirm wafer surface damaged to choose one way to particle removed rate and surface roughness. In this thesis, decreased 4~5 times concentration, but particle remove counts not decreased very much, and in test wafer C could know wafer surface damage decreased. So used dulite APM to clean wafer were workable.