Abstract: An improved chemical vapor deposition method is disclosed that increases the uniformity of silicon carbide epitaxial layers and that is particularly useful for obtaining thicker epitaxial layers. The method comprises heating a reactor to a temperature at which silicon carbide source gases will form an epitaxial layer of silicon carbide on a substrate in the reactor; and then directing a flow of source and carrier gases through the heated reactor to form an epitaxial layer of silicon carbide on the substrate with the carrier gases comprising a blend of hydrogen and a second gas in which the second gas has a thermal conductivity that is less than the thermal conductivity of hydrogen so that the source gases deplete less as they pass through the reactor than they would if hydrogen is used as the sole carrier gas.

Abstract: An improved chemical vapor deposition method is disclosed that increases the uniformity of silicon carbide epitaxial layers and that is particularly useful for obtaining thicker epitaxial layers. The method comprises heating a reactor to a temperature at which silicon carbide source gases will form an epitaxial layer of silicon carbide on a substrate in the reactor; and then directing a flow of source and carrier gases through the heated reactor to form an epitaxial layer of silicon carbide on the substrate with the carrier gases comprising a blend of hydrogen and a second gas in which the second gas has a thermal conductivity that is less than the thermal conductivity of hydrogen so that the source gases deplete less as they pass through the reactor than they would if hydrogen is used as the sole carrier gas.

Abstract: An improved retainer element has a mounting section which is connected with a rim portion of a panel. A longitudinally extending main spring section of the retainer element extends from the mounting section. A retainer section of the retainer element is connected with an end of the main spring section opposite from the mounting section. The retainer section includes a retainer flange and a pair of retainer arms which engage opposite sides of the rim portion of the panel. When the panel is moved into position relative to the support frame, a cam surface on the retainer flange engages the support frame and transmits force to deflect the main spring section of the retainer element. The retainer flange then snaps into engagement with the support frame. The retainer arms slide along opposite side surfaces of the rim portion of the panel to guide movement of the main spring section relative to the panel.