公开(公告)号：US4728869A

公开(公告)日：1988-03-01

申请号：US845212

申请日：1986-03-27

申请人： Noel H. Johnson ,  Gary C. Elliott

发明人： Noel H. Johnson ,  Gary C. Elliott

IPC分类号： C23C16/44 ,  C23C16/455 ,  C23C16/52 ,  G05D16/20 ,  H02P5/16

CPC分类号： C23C16/45557 ,  C23C16/4412 ,  C23C16/52 ,  G05D16/2066 ,  Y10S388/90 ,  Y10S388/91 ,  Y10S388/929 ,  Y10S388/933

摘要： A low pressure control system for chemical vapor deposition (CVD) apparatus, including a vacuum pressure chamber and an exhaust pump, is provided by a vacuum pump DC motor which is supplied power from a DC motor speed controller coupled to a DC control input signal from a pulsewidth modulation DC converter. The converter receives a single pulsewidth modulated pulse train having its percentage of modulation controlled in accordance with a DC to pulsewidth modulation controller which operates in accordance with the difference between a pair of DC input signals corresponding to the actual pressure inside the vacuum pressure chamber and a desired or set point pressure respectively. The vacuum pump motor speed and accordingly the exhaust pump is controlled with a high degree of precision, thereby providing improved coating uniformity of semiconductor wafers being fabricated by the CVD apparatus.

摘要翻译： 包括真空压力室和排气泵的化学气相沉积（CVD）装置的低压控制系统由真空泵直流电动机提供，该真空泵直流电动机由直流电动机速度控制器供电， 脉宽调制DC转换器。 转换器接收单个脉宽调制脉冲串，其脉宽调制百分比根据直流 - 脉冲宽度调制控制器控制，该脉冲宽度调制控制器根据与真空压力室内的实际压力相对应的一对直流输入信号之间的差异操作， 分别需要或设定点压力。 真空泵电机的转速以及相应的排气泵被高精度地控制，从而提供由CVD装置制造的半导体晶片的改进的涂层均匀性。